Conditioning for Skiing and Ski Injury Prevention
MATTHEW C. MORRISSEY, MA, PT,* JUDY LEE SETO, MA, PT,t CLlVE E. BREWSTER, MS, PT,t
ROBERT K. KERLAN, MDt
As the popularity of skiing has risen in the United States over the last two decades so has the incidence of skiing injuries. The possibility exists that a proper conditioning program may decrease the frequency and severity of musculoskeletal injuries that occur during skiing. To ascertain the most appropriate components of a ski conditioning program, a review of the literature regarding downhill and crosscountry
skiing is presented. Specifically, the literature was evaluated to determine the most recent research findings in the areas of physiological demands in downhill and cross-country skiing, the frequency and types of injuries that occur during each type of skiing, and the most common mechanisms of injury for the major types of ski
injuries. This information was used to devise a muscular strengthening and musculoskeletal stretching program that may be useful in conditioning for skiing and for prevention of ski injuries.
The two fastest growing outdoor recreational the health professional and recreational skier in a activities in the United States of America are conditioning program necessaryfor a safe, enjoycross- country skiing and downhill ~ k i i n gN. ~in e able ski experience. Safety and enjoyment can be percent of the American population over 12 years best attained through a program that emphasizes of age participate in skiing. This increase in the education of the patient in equipment and haznumber of skiers has resulted in an increase in ards, and training to improve flexibility, muscular the number of musculoskeletal injuries requiring strength and endurance. medical attention, not to mention muscular strain and soreness not requiring medical care. The
chances of injury during skiing exceed football, PHYSIOLOGICAL DEMANDS IN SKIING which many people consider to be one of the most dangerous sports.20 The major requisite to devising a conditioning
Proper physical conditioning is important to pre- program for skiing is the analysis of the physiovent
joint injury as well as muscular strains and logical demands incurred the body during soreness. Fatigue is a major factor causing ski skiing. With this information, a Program may be injury.~3.~4.~3.28.37,4~ not surprising since, devised to properly prepare the body to satisfacas ~ ~ ~ ~ap~tlyts tahted2, 0 isp robably the torily meet these physiological demands. The end sport in which the largest proportion of people result of the use of a proper conditioning program
who participate, especially adults, do not condim Can be a ski exertiom themselves." A strong muscle that has adequate endurance is more resistant to the fatigue The physiological demands are much different
that causes muscular soreness and may cause in skiing as compared to cross-country
injury. ~~~~i~~~~~a~n~d ~m~u scular endurance skiing. Alpine skiing is characterized by high intenalso
add t~ the enjoyment of the skiing activity. sity exercise over a relatively brief period of time,
The purpose of this manuscript is to educate 1 .O-2.5 Whether a high intensity exercise
mainly taxes the anaerobic system or requires
energy from the aerobic system is partly
* Department of Physical Therapy. University of Wisconsin, La Crosse, time dependent. Karl~son*h~as noted the follow-
W154601.
t ~erlan-~obOer thopaedic Clinic, Inc., 501 E. Hardy st., Inglewocd, ing relationship between the length of time of the
CA 90301. exercise and the energy system used:
428
JOSPT March 1987 SKI CONDITIONING 429
Time O/O Anaerobic
40-50 seconds 50
11/2 minutes 30-40
21/2 minutes 15-25
Alpine skiing requires using both the anaerobic
and aerobic systems, relying on the former system
for 30-35% of its energy.41 In short, conditioning
programs for alpine skiing should consist
of exercises of brief duration that will tax both the
anaerobic and aerobic systems.
Another factor in devising a training program
for alpine skiing is analyzing the muscles used in
this activity, and the type of contraction (i.e.,
static, dynamic, concentric, eccentric) that these
muscles typically perform during this sport. Electromyographic
(EMG) analysis can measure utilization
of various muscles during a specific activity.
Due to the difficulties of analysis in an alpine
environment, few studies have been published on
EMG activity during downhill ~kiing.".'~.~'
Of the three studies published, the one that is
most applicable to the purpose of this paper is
the Louie et al. study.27 They studied the gluteus
medius and maximus, biceps femoris, semitendinosus,
peroneus longus, and tibialis posterior
muscles. They noted that all these muscles were
active at various intensities during torsional movements
of the lower extremity in skiing. A great
need for more skiing EMG research is obvious.
Without EMG studies the best analysis of muscular
activity is a theoretical one in which, based
on the movements performed or the positions
maintained at each joint, estimates of the muscle
group most utilized are noted. Foss and Garrick16
have presented an excellent review of the muscles
used in downhill skiing. These muscles are
grouped according to the actions they perform
(Table 1).
The type of muscle contraction used in downhill
skiing varies and is partly dependent on the particular
muscle group studied and also on the
experience of the individual skier. Most of the
muscular analysis in downhill skiing has appropriately
centered on s t a t i ~ ' ~a,n*d~ d y n a m i ~ ' ~ . ~ ~ . ~ ~
quadriceps contractions. The quadriceps is the
muscle group that is most important to the skier
as it controls changes in the stiffness of the knee
in the sagittal plane. Static muscular contractions
may block the arterial transport of oxygen to the
muscle.25 By necessity, the muscle must then
resort to use of the anaerobic energy system.
With increasing skill, the contractions become
more dynamic and less ~ t a t i c .H~o~w.ev~e~r, the
static component is very important for all downhill
skiers. Its importance has been displayed by the
greater isometric quadriceps strength of downhill
skiers compared to athletes of various sport^.'*^'^
In the same sample of athletes, the quadriceps of
the skiers were not as strong as some of the
other athletic groups in dynamic contractions.
Other muscles besides the quadriceps must
also act both dynamically and statically. These
are the actions that are caused by muscles that
contract both statically and dynamically:
1) Trunk rotation
2) Trunk lateral flexion
3) Hip extension
4) Hip abduction
5) Hip adduction.
The predominantly static contractors result in:
1) Trunk flexion
2) Trunk extension
3) Ankle inversion
4) Ankle eversion
5) Ankle plantarflexion
6) Finger flexion.
Finally, the muscles that act predominantly in
the dynamic mode are those that account for the
following actions:
1) Hip rotation
2) Hip flexion
3) Arm extension
4) Elbow extension.
There are multiple classifications of dynamic
muscular contraction based on: 1) speed (fast
versus slow); 2) movement that occurs with the
contraction (eccentric versus concentric); and 3)
intensity (maximal versus submaximal). In downhill
skiing, contractions of the quadriceps are typ
ically of high intensity at slow velocity, and are
both concentric and eccentric.15 In sum, training
of the quadriceps should include both static and
slow dynamic exercise at high intensity with the
dynamic exercise taxing the muscle both concentrically
.and eccentrically. For the purposes of
this paper we will assume that the other dynamic
muscles function in a similar manner as the quadriceps,
i.e., slow velocity, high intensity eccentric
and concentric contractions. It is apparent that
more research is needed to assess the specific
modes of contraction of the other dynamic muscles.
Special demands are required of other systems
of the human body because of the high speeds
and forces inherent in alpine skiing. The neuromuscular
system must be trained for balance to
allow efficient movement down the ski slope and
to prevent falls. The skeletal system is taxed
heavily in ski falls and flexibility exercises are
necessary to allow adequate joint movement that
must occur in the high momentum/velocity falls.
While alpine skiing relies on both the aerobic
and anaerobic systems for energy production,
cross-country skiing requires, for the most part, a
430 MORRISSEY ET AL JOSPT Vol. 8, No. 9
TABLE 1
Muscles important in downhill skiing'
Action Musclds) Ski functionls)
1. Neck extension Spinalis Hold head position
2. Trunk flexion Rectus abdominus Hold ski position
lnitiate and block turning
3. Trunk extension Trunk extensors Hold ski position
4. Lateral trunk flexion Quadratus lum- Hold ski position
borum
5. Trunk rotation Sacrospinalis Initiate turning
Internal and external
obliques
6. Shoulder extension Posterior deltoid Poling
Latissimus dorsi Rising from fall
Teres major
Triceps brachii
7. Elbow extension Triceps brachii Poling
Rising from fall
8. Finger flexion Finger flexors Pole grasp
9. Hip extension Gluteals Pelvic thrust
Hamstrings Movement out of tuck
position
Holding ski position
10. Hip flexion Rectus femoris Return leg to ski posilliopsoas
tion
11. Hip adduction Adductor magnus, Hold legs together
longus, and
brevis
12. Hip abduction Gluteus medius Heel thrust
Tensor fascia latae
13. Hip rotation Hip internal and ex- Heel thrust
ternal rotators
14. Knee extension Quadriceps femoris Hold ski position
15. Ankle inversion Tibialis anterior and Edging
posterior
16. Ankle eversion Peroneals Edging
17. Ankle plantarflexion Triceps surae Hold ski position
Derived from Foss and Garrick.16
strong and efficient aerobic system. Although under
dispute, it has been noted that the aerobic
system is taxed more in uphill skiing than it is in
uphill treadmill r~nningH.~ay mes and Dickenson"
noted a greater maximal oxygen uptake in crosscountry
skiers as compared to downhill skiers. In
fact, Saltin and A ~ t r a n sdtu~d~ie d a large group of
athletes from different sports and noted that the
cross-country skiers had the greatest maximal
oxygen uptake. Even when maximal oxygen uptake
was considered relative to body weight, the
cross-country skiers were second only to marathon
runners.24
As mentioned previously, an alpine skier receives
approximately 65-7O0/0 of their energy
from the aerobic system. This is in contrast with
the estimated 95-1 00% reliance on the aerobic
system in cross-country skiing.24 Not only are
cross-country skiers able to reach high values for
maximal oxygen uptake, they are also able to
maintain high percentages of their maximal oxygen
uptake over long periods during skiing. Maintenance
of 80% of maximum oxygen uptake for
hours has been noted among cross-country
skier^.^ Therefore, there is little doubt about the
necessity for a strong and efficient aerobic system
to perform cross-country skiing at an enjoyable
level. On a competitive level, the ability to maintain
near maximum oxygen energy metabolism is a
major determinant of success when skill and lean
body mass are
Cross-country skiing requires concentric muscular
contractions that are less intense and of
higher velocity than those required in downhill
skiing. Thus, strengthening should emphasize exercises
that are faster in speed, greater in repetition,
and against smaller loads than those used in
downhill ski conditioning.
Although there are few EMG reports for downhill
skiing, there are even fewer concerning crosscountry
skiing. Hixsonl' has described the muscles
that are important in cross-country skiing.
JOSPT March 1987 SKI CONDITIONING 43 1
The muscles and their major functions in crosscountry
skiing are listed in Table 2. In general, the
muscles that are of greatest importance in providing
the power necessary for propelling the skier
are the extensors. They provide the pole thrust,
by rapid extension of the shoulder (posterior deltoid,
latissimus dorsi, teres major, and triceps
brachii) and elbow (triceps brachii), and the kick
by strong extension of the low back (trunk extensors),
hip (gluteals and hamstrings), knee (quadriceps),
and ankle (triceps surae).
SKI INJURIES
When devising an injury prevention program,
understanding the parts of the musculoskeletal
system most commonly injured during skiing and
the biomechanics involved in their mechanical failure
is important. Identifying and specifically
strengthening muscles that act to protect frequently
injured areas is vital in designing a conditioning
program.
Downhill ski injuries most frequently occur in
the lower extremity (versus the upper extremity,
spine, etc.). Table 3 describes the injury frequency
pattern for the major areas of injury in downhill
skiing. A 1982 survey of ski injuries noted that of
the total number of injuries, 27.8% occur at the
knee, and of Ithese, knee ligament injury is most
frequent (Table 4).19
The usual mechanism of knee ligament injury is
a fall that results in a knee valgus force, combined
with tibial external rotation." This usually occurs
when one ski becomes fixed or loses its parallel
alignment to the ski that is moving in the correct
direction. This type of injury is more common in
novice skiers who have a tendency to ski with
their legs spread apart in attempting to maintain
a wider, more stable base of support. These
combined forces may result in injury of the medial
collateral ligament (MCL), anterior cruciate ligament
(ACL), and one or both menisci. Medial
collateral ligament injury with or without ACL injury
represents 61.3% of the injuries.lg A possible
method of prevention for this frequent type of
injury is to strengthen the muscles of the leg that
act to assist these two ligaments in their function.
Stress on the MCL occurs with tibial external
rotation and valgus force. The q~adriceps,~'.~"
sartorius,30 and hamstrings3' may dynamically o p
pose knee valgus force, while the muscles comprising
the pes anserinus (semitendinosus, gracilis,
and sartorius), and the other medial hamstring
muscle, the semimembranosus, offer the
major opposition to tibial external rotation. Use of
resisted knee flexion, knee extension, and tibial
internal rotation will specifically strengthen the
hamstrings, quadriceps, and pes anserinus, respectively.
Lateral collateral ligament (LCL) and posterior
cruciate ligament (PCL) injuries occur less frequently
than MCL injuries. Injury to the LCL represents
4.2% of the knee injuries that occur during
skiing, while PCL injuries represent only 1 % (compared
to 61.3% for the MCL).lg Opposite to MCL
injury, LCL injury occurs with combined knee
TABLE 2
Muscles important in cross-country skiing
Action Muscle(s) ' Ski function(s)
1. Trunk flexion
2. Trunk extension
3. Scapular adduction
4. Shoulder extension
5. Elbow extension
6. Hip extension
7. Hip flexion
8. Knee extension
Rectus abdominus
Trunk extensors
Rhomboid major
and minor
Trapezius
Posterior deltoid
Latissimus dorsi
Teres major
Triceps brachii
Triceps brachii
Gluteals
Hamstrings
Rectus femoris
lliopsoas
Quadriceps
Double poling
Stable base
Stable base
Assist in kick
Poling
Poling
Poling
Kicking
Leg return after kick
Kicking
Hold ski position
Leg return after kick
Kicking
9. Ankle dorsiflexion
10. Ankle plantarflexion
Tibialis anterior
Triceps surae
JOSPT Vol. 8, No. 9
TABLE 3
Areas and percentage of the body injuries during downhill
skiing*
Area Percentage
Lower extremity 65
Upper extremity 29
Head and face 3
Chest 2
Back
Total
From Davis et aI.*
TABLE 4
Knee injuries in downhill skiing*
% of knee
injuries
Ligament sprains
Medial collateral with or without
anterior cruciate
"Isolated" anterior cruciate
Lateral collateral
Posterior cruciate or capsule
Complete dislocation
SUBTOTAL
Other knee injuries
Contusions
Possible tom menisci
Patellar: chondromalacia, pain, subluxation
Laceration
Tibial plateau fracture
Patellar fracture
SUBTOTAL
TOTAL
'10 of total
injuries
17.1
2.0
1.2
0.3
20.5
3.1
1.9
1.5
0.6
0.1
0.1
7.3
27.8
From Howe and Johnson.lg
varus force and internal tibial rotation. These
forces result when a skier catches the outside
edge of one ski, causing it to run across the other
ski. Aggin, this type of fall is more common in
novices. A strong tibial external rotation group
(the lateral hamstring-biceps femoris) as well as a
strong iliotibial band may aid in preventing excess
tibial internal rotation and knee varus. The biceps
femoris may be strengthened using resisted knee
flexion and tibial external rotation. The gluteus
maximus and tensor fascia latae, by way of the
iliotibial band, may be strengthened with resisted
hip abduction and extension.
Two other significant knee injuries that may be
prevented with proper conditioning are patellofemoral
dysfunction and derangement. Patellofemoral
dysfunction, for the purpose of this paper,
includes patellofemoral pain syndrome, patellofemoral
arthralgia, patellar tendinitis, parapatellar
pain, and iliotibial band inflammation. The iliotibial
band has been included in the classification because
of its attachment to the patella. One cause
of these disturbances is overloading of the patellofemoral
joint. Downhill skiing places great loads
on the patellofemoral joint as the skier maintains
a flexed knee position which requires a strong
quadriceps contraction.
Preventing patellofemoral dysfunction can be
best obtained by strengthening the quadriceps
musculature. A strong quadriceps is necessary
for proper function at the patellofemoral joint.
Resisted knee extension acts to strengthen the
quadriceps. In addition, hamstring and calf
stretching should also be performed to decrease
the load on the quadriceps in knee extension
activity. A flexible joint requires less energy to
move and can more further within its range.26,32
Antich et aL2 have noted that patients with patellofemoral
dysfunction had significantly tighter
hamstrings in the involved leg.
Patellar derangement includes patellar subluxation
and dislocation. Injuries of this type are often
confused with MCL injury for two reasons. First,
the mechanism of injury is the same for both
groups, i.e., knee valgus force combined with
tibial external rotation. Second, t6e area of pain
is in close proximity for each injury. In patellar
subluxation or dislocation, pain may be localized
at the stretched or torn medial retinaculum, while
in MCL injury pain may be located along the length
of the ligament. A program preventing patellar
derangement is, in essence, a combination of the
prevention program for MCL injury and patellar
dysfunction. Emphasis is placed on strengthening
the muscles preventing external tibial rotation,
and also on the quadriceps which control patellar
tracking.
Sprains may occur at the foot and ankle, but
these represent only 2% of the total number of
injuries.39 Tibial fracture is another injury that occurs
in downhill skiing and this represents 3.1%
of the total number of inj~ries.~F'r actures of this
type are becoming much less frequent in downhill
skiing.39
Two other lower extremity injuries that may be
prevented through an adequate conditioning program
are peroneal tendon subluxation and gastrosoleus
strains. Trevino and Alvarez3' described
peroneal tendon subluxation as "one of the most
overlooked skiing injuries." These authors reported
that this injury represents only 0.5O/0 of the
JOSPT March 1987 SKI CONDITIONING 433
total number of injuries, but warned that this may
actually be an underestimation. Regardless of the
frequency of this injury, we believe that a strong,
flexible peroneal muscle group may prevent this
type of injury. Strengthening of the peroneals may
be obtained through resisted ankle eversion and
foot plantarflexion exercises. Stretching of the
ankle into inversion and dorsiflexion will maintain
mobility of the peroneal muscle group. This
stretching is vital because a lack of full dorsiflexion
range of motion is important in the mechanism of
this injury, forward falling into ankle dorsifle~ion.~~
Forced dorsiflexion in a forward fall causing
peroneal subluxation is the same mechanism that
causes gastrocsoleus strains.39 To prevent injury
of this musculotendinous unit, resistive plantarflexion
and stretching into ankle dorsiflexion
should be performed to assure strength and flexibility,
respectively.
Though lower extremity injuries are the dominant
injuries in downhill skiing, injury also occurs
to the upper extremity. Upper extremity injuries
represent 25% of the total number of injuries that
occur in downhill skiing.' This compares with the
approximation of 60% that occur at the lower
extremity. Injury to the thumb accounts for over
one-third of the'upper extremity inj~ries.T~h' umb
injuries usually consist of ulnar collateral ligament
sprain. This typically results from a fall onto an
outstretched hand causing the thumb to be forced
into abduction and e~tension.~W' e suggest three
measures of prevention for this injury. First,
strengthening the thumb musculature to prevent
excessive extension and abduction should be performed
with ball squeeze exercises. Second,
proper instruction in correct falling using shouldertrunk
rolling may decrease the frequency of this
injury without exposing the shoulder, neck, and
head to injury. Finally, skiing without a strap may
be helpful in decreasing thumb injury.
In addition to thumb injury, the shoulder is
frequently injured representing approximately
one-fourth of the upper extremity inj~ries.~T'h e
most frequent of these is anterior shoulder subluxation
or dislocation. Injury of this type results
from a fall on an outstretched arm. To protect
against this injury again we advise a program of
stretching and strengthening as well as instruction
in shoulder trunk roll falling. An exercise program
focusing on strengthening the anterior shoulder
musculature may decrease anterior movement of
the humeral head in the glenoid fossa. Especially
emphasized is the subscapularis muscle since it
is a major anterior ~tabilizer.~T' his muscle may
be strengthened by resistive internal rotation. To
strengthen the other anterior shoulder musculature,
resistive shoulder flexion and horizontal adduction
should be performed. Aronen and Regan3
have presented the successful results of their
program of shoulder strengthening for prevention
of dislocation recurrence.
Besides shoulder musculature strengthening
we also suggest stretching of the shoulder joint
and musculature. A joint with normal flexibility
may be less likely to suffer derangement than a
hypomobile joint. At the same time a hypermobile
person should not increase mobility through
stretching. For skiing, the shoulder should be
stretched in the position that will offer enough
mobility for the most typical mechanical cause of
injury-external rotation and horizontal abduction
with the arm in 90° abduction.
Cross-country skiing, though growing at a rapid
rate, is still not as popular as downhill skiing. In
addition, the medical literature devoted to crosscountry
skiing compared to downhill is disproportionate.
For the sports medicine specialist, crosscountry
skiing differs from downhill skiing mainly
in the physiological demands and the smaller number
of injuries that occur with this type of skiing.
The major factor in both of these differences
results from the means of propulsion in each type
of skiing, i.e., downhill relies on gravity while
cross-country relies on self propulsion.
The rate of injury in downhill skiing has been
estimated to be from two to 26 times greater than
cross-country skiing.43 However, injuries do occur
in cross?country skiing and warrant detailed analysis.
Concern over cross-country skiing injuries can
be justified by the study of Jarvinen and ~annus~'
who noted in a group of ACL injured individuals
that 50% were injured cross-country skiing.
As in downhill skiing, the lower extremity is the
area most often injured in cross-country skiing.
Lower extremity injuries represent 61 % of the
injuries while approximately 26% are of the upper
extremity (compared to 60 and 25%, respectively,
for downhill skiing).42 Another study has noted
that 49% of the cross-country injuries are of the
lower extremity while 41% are of the upper extremity.'
Most of the injuries in cross-country
skiing occur when the individual is being propelled
by gravity down an incline. Fortunately, this type
of propulsion represents only a minor part of the
ski activity. The major force in propulsion is the
activity of the skier's musculature. As a result, the
Y ET AL JOSPT Vol. 8, No. 9
conditioning necessary for self propulsion differs
from the gravity propulsion program and the injuries
in gravity propulsion are more serious and
occur more frequently.
As one might expect, the mechanism of injury
during hilly descent in cross-country skiing also
mimics those occurring in downhill skiing, e.g., a
fall results in knee valgus and tibia1 external rotation,
thus injuring the medial collateral ligament.
Since the mechanisms of injury are similar to
those which occur in downhill injuries, the muscles
that require training to prevent injuries are similar
to those described in the downhill ski injury prevention
section.
MUSCULOSKELETAL CONDITIONING
PROGRAMS
Based on the information presented in the sections
on physiological demands and mechanisms
of injury, a specific conditioning program for the
musculoskeletal system may be devised. Below
is a description of two suggested programs, one
for downhill skiing and the other for cross-country
skiing. These are only suggested programs and
may serve as a framework for programs that have
modifications and additions to fit an individual's
needs or preferences.
The following programs should be performed
at least twice a week during the off-season and
more frequently-at least three times a weekduring
the ski season. Ideally, the workout program
will be divided into strengthening days and
endurance days to be performed on alternate
days for a total of 6 days per week with 1 day off
each week. For example, strengthening exercises
should be performed Monday, Wednesday, and
Friday while endurance exercises are performed
on Tuesday, Thursday, and Saturday with Sunday
as the day off. At the very least, the strength and
endurance sessions should each occur twice per
week.
For the strengthening exercises we have noted
successful results using a protocol of one to three
sets of 10 to 20 repetitions with a 1 minute rest
period between sets. At no time during the exercise
program should joint pain be experienced by
the athlete. Muscular "fatigue pain," i.e., burning
discomfort in the muscle during exercise, is allowed
and is actually a goal of the individual
exercise because this indicates that the muscle is
being taxed. Finally, the resistance used (or the
muscle tension elicited) should be the maximum
the muscle group can work against for the number
of sets and repetitions used. Resistance should
be increased whenever the muscle is not being
taxed to the fullest amount.
Cardiovascular endurance should be trained for
a minimum of 20 minutes at a level that causes
the heart rate to increase to at least 70% of its
maximum (equal to 220-age).29 If endurance training
is performed on the same day as the strengthening
program, it is suggested that the endurance
training occur prior to the strengthening to allow
the body to be more "warmed up" for the strengthening
exercises.
The endurance training should differ for downhill
skiers compared to cross-country skiers.
Downhill skiing usually consists of short high intensity
work punctuated by brief periods of rest
(while still on the slope going down) or longer rest
periods (chair lift return to top of slope). As a
result, brief, high intensity sprints should occur
throughout the training session. For cross-country
skiing, endurance training should be of longer
duration than the downhill ski endurance program.
Low intensity exercise, relative to the sprints used
for downhill skiing, should be employed.
DOWNHILL SKI PROGRAM
Combining the muscles importdnt in the downhill
ski activity with the muscles that may act in
musculoskeletal injury prevention, the specific exercise
for strengthening can be devised. In each
case a number of methods may be used to offer
resistance to the muscle group being exercised.
These will be divided into upper extremity, trunk,
and lower extremity exercises.
A. Upper Extremity
Resistance should be offered to the following
muscle groups.
1. Shoulder flexors. Performed dynamically to
increase their function in offering anterior stability
to the joint.
2. Shoulder extensors. Performed dynamically
to increase their function in poling and rising
from falls.
3. Shoulder internal rotators. Performed dynamically
to offer greater anterior shoulder stability.
4. Shoulder horizontal adductors. Performed
dynamically to offer greater anterior shoulder
stability.
5. Elbow extensors. Performed dynamically to
JOSPT March 1987 SKI CONDITIONING 435
increase their function in poling and rising
from falls.
6. Finger flexion. Perform ball squeezes for 5-
10 minutes at a time to protect against thumb
injury.
B. Trunk
1. Neck extensors. Performed statically to increase
their ability to hold the head position.
2. Trunk flexors. Performed dynamically to increase
their ability to hold the ski position
and to initiate and block turning.
3. Trunk extensors. Performed dynamically to
increase their ability to hold the skin position.
4. Trunk rotators. Best performed statically to
increase their ability to initiate turning.
5. Lateral trunk flexors. Performed dynamically
to increase their ability to hold the ski position.
C. Lower Extremity
1. Hip flexors. Performed dynamically to increase
their ability to return the leg to the
proper ski position.
2. Hip extensors. Performed dynamically and
statically gince this muscle group acts in both
modes during downhill skiing. Increased
strength of this muscle group may increase
its ability to function in pelvic thrust, movement
out of tuck position, and holding of the
ski position.
3. Hip adductors. Performed statically and dynamically
to increase their ability to hold the
legs together.
4. Hip abductors. Performed dynamically to increase
their ability in heel thrusting.
5. Knee extensors. Performed statically and dynamically
to increase its ability to hold the ski
position, offer knee stability against valgus
forces, and prevent patellofemoral pathology.
6. Knee flexors. Performed dynamically to offer
support to anterior and rotational knee stability.
7. Tibial internal and external rotators. Performed
dynamically to offer support to rotational
and valgus (sartorius) knee stability.
8. Ankle invertors. Performed statically to increase
their ability in edging.
9. Ankle evertors. Performed statically to increase
their ability in edging and prevention
of peroneal tendon subluxation.
10. Ankle plantarflexors. Performed statically to
increase their ability to hold ski position and
prevent gastrosoleus strains.
Stretching is another important facet of the ski
conditioning program. For optimal results and
safety we suggest static, musculature stretching
of 10-20 sec duration (except for trunk-2-4 sec
duration) repeated 10-15 times per position of
stretch. Light stretching should be performed before
workouts and restretching with stronger
force should be done immediately after the workout
while the muscle is "warmed up." Stretching
should be performed daily with or without the
strengthening exercises. The most important time
of the year for stretching is during the season,
especially on days when the individual is skiing.
Again, in these instances stretching should occur
before and after the skiing. In fact, periodic
stretching throughout the ski day is optimal.
Anderson1 has presented excellent illustrations
of stretching positions. The stretching positions
that are most important for the downhill skier are:
1. Shoulder external rotation with horizontal abduction.
Performed at 90' of shoulder abduction
in a supine position, this exercise will
increase the mobility of the anterior shoulder
joint and musculature.
2. Trunk flexion. This exercise stretches the posterior
back soft tissue.
3. Trunk extension. This exercise helps to maintain
the normal lumbar curvature.
4. Trunk rotation. This exercise offers added mobility
for trunk rotation that is vital to the turning
action of the skier.
5. Hip flexion with knee straight (hamstrings).
Thi$ exercise is important not only as a possible
prevention for patellofemoral problems
but also as a preventive measure for hamstring
muscle strains and tears.
6. Ankle dorsiflexion (calf). Should be performed
with the knee straight and with the knee bent
to emphasize stretching of the gastrocnemius
and soleus, respectively.
7. Ankle dorsiflexion (peroneals). Performed similar
to the soleus stretch except the foot should
be placed in a position of inversion to specifically
stretch the peroneals.
A final component of the downhill program is
an exercise that mimics the ski activity and will
increase the skier's balance, agility, and endurance.
The exercise, called the pillow jump, is
performed by standing parallel to a pile of pillows
or similar object and jumping sideways from one
side of the pillows to the other. As the exercise
436 MORRISSEY ET AL JOSPT Vol. 8, No. 9
becomes easier to perform, more jump repetitions ankle dorsiflexors should be performed. The knee
and a higher pile of pillows should be used. extensors are also important in holding the ski
position and this requires isometric exercise of
CROSS-COUNTRY SKI PROGRAM these muscles.
There are two major differences between the
downhill ski program and the cross-country ski
program. One of these differences has been described
previously, i.e., that the cardiovascular
endurance exercise of the cross-country skier
should be of longer duration and less intensity.
The second difference consists of the manner in
which the strengthening exercises are performed.
The cross-country skier should perform strengthening
exercises with more repetitions and less
resistance. This is done in order to mimic the
repetitive, lower intensity muscular contractions
of the cross-country ski activity.
Hixson,'' in his excellent text, has described
the muscles that are important in cross-country
skiing. Focusing on the muscles important in the
cross-country ski activity (Table 2) with the muscles
that may act in musculoskeletal injury pre-
The stretching program for the cross-country
skier is similar to the downhill skier's stretching
program with special emphasis on the following:
1. Triceps brachii/shoulder extensors. Performed
with the elbow and shoulder flexed to end
range.
2. Trunk. As described for the downhill ski program.
3. Buttocks. Performed in sitting with the leg
stretched across the abdomen with the knee
flexed.
4. Quadriceps/iliopsoas. Performed standing
with the knee in complete flexion and the hip
extended.
5. Hamstrings. As described for the downhill ski
program.
6. Gastrocnemius/soleus. As described for the
downhill ski program.
vention, a specific exercise strengthening proaram
mav be devised. The exercises devised to SUMMARY
Erevent iijury have been described in the downhill
program; therefore, only the exercises for the
muscles used in the cross-country ski activity will
be described. In each case a number of methods
may be used to offer resistance to the muscle
group being exercised. The exercises will be divided
into upper extremity, trunk, and lower extremity.
Exercise of the upper extremity focuses on
three muscle groups and their specific function in
poling. These three muscle groups are the shoulder
extensors, scapular adductors, and elbow
extensors. All exercise of these muscles should
be performed in a dynamic fashion.
Dynamic trunk exercises should be devised to
offer resistance to the flexors and extensors. The
flexors are important in double poling. The extensors
are important in assisting in the kick motion.
Both muscle groups are important in offering a
stable base of support to the continuously moving
extremities.
For the lower extremities exercise is centered
on the functional capacity of thigh and leg musculature
in kicking, leg return after kicking, and
holding the ski position. For kicking, dynamic resistance
exercise of the hip extensors, knee extensors,
and ankle plantarflexors should be performed.
For returning the leg after kicking, dynamic
resistance exercise of the hip flexors and
The popular sports of downhill and cross-country
skiing require proper conditioning and may
result in a number of musculoSkeletal injuries.
Injuries of this variety may be prevented by physical
conditioning of the skiing enthusiast in a yearround
program. We have presented a program
that may be useful in both clinical and training
settings as a method to enhance muscular endurance
necessary for increased enjoyment of the
skiing experience and to condition the musculoskeletal
system for the substantial demands required
of it during downhill and cross-country
skiing. Research is needed to determine the effectiveness
of conditioning programs such as this
in decreasing the prevalence of musculoskeletal
injury in sport.
The authors wish to thank Karen Kassa and Lillian Smith for their
assistance in manuscript preparation.
MATTHEW C. MORRISSEY, MA, PT,* JUDY LEE SETO, MA, PT,t CLlVE E. BREWSTER, MS, PT,t
ROBERT K. KERLAN, MDt
As the popularity of skiing has risen in the United States over the last two decades so has the incidence of skiing injuries. The possibility exists that a proper conditioning program may decrease the frequency and severity of musculoskeletal injuries that occur during skiing. To ascertain the most appropriate components of a ski conditioning program, a review of the literature regarding downhill and crosscountry
skiing is presented. Specifically, the literature was evaluated to determine the most recent research findings in the areas of physiological demands in downhill and cross-country skiing, the frequency and types of injuries that occur during each type of skiing, and the most common mechanisms of injury for the major types of ski
injuries. This information was used to devise a muscular strengthening and musculoskeletal stretching program that may be useful in conditioning for skiing and for prevention of ski injuries.
The two fastest growing outdoor recreational the health professional and recreational skier in a activities in the United States of America are conditioning program necessaryfor a safe, enjoycross- country skiing and downhill ~ k i i n gN. ~in e able ski experience. Safety and enjoyment can be percent of the American population over 12 years best attained through a program that emphasizes of age participate in skiing. This increase in the education of the patient in equipment and haznumber of skiers has resulted in an increase in ards, and training to improve flexibility, muscular the number of musculoskeletal injuries requiring strength and endurance. medical attention, not to mention muscular strain and soreness not requiring medical care. The
chances of injury during skiing exceed football, PHYSIOLOGICAL DEMANDS IN SKIING which many people consider to be one of the most dangerous sports.20 The major requisite to devising a conditioning
Proper physical conditioning is important to pre- program for skiing is the analysis of the physiovent
joint injury as well as muscular strains and logical demands incurred the body during soreness. Fatigue is a major factor causing ski skiing. With this information, a Program may be injury.~3.~4.~3.28.37,4~ not surprising since, devised to properly prepare the body to satisfacas ~ ~ ~ ~ap~tlyts tahted2, 0 isp robably the torily meet these physiological demands. The end sport in which the largest proportion of people result of the use of a proper conditioning program
who participate, especially adults, do not condim Can be a ski exertiom themselves." A strong muscle that has adequate endurance is more resistant to the fatigue The physiological demands are much different
that causes muscular soreness and may cause in skiing as compared to cross-country
injury. ~~~~i~~~~~a~n~d ~m~u scular endurance skiing. Alpine skiing is characterized by high intenalso
add t~ the enjoyment of the skiing activity. sity exercise over a relatively brief period of time,
The purpose of this manuscript is to educate 1 .O-2.5 Whether a high intensity exercise
mainly taxes the anaerobic system or requires
energy from the aerobic system is partly
* Department of Physical Therapy. University of Wisconsin, La Crosse, time dependent. Karl~son*h~as noted the follow-
W154601.
t ~erlan-~obOer thopaedic Clinic, Inc., 501 E. Hardy st., Inglewocd, ing relationship between the length of time of the
CA 90301. exercise and the energy system used:
428
JOSPT March 1987 SKI CONDITIONING 429
Time O/O Anaerobic
40-50 seconds 50
11/2 minutes 30-40
21/2 minutes 15-25
Alpine skiing requires using both the anaerobic
and aerobic systems, relying on the former system
for 30-35% of its energy.41 In short, conditioning
programs for alpine skiing should consist
of exercises of brief duration that will tax both the
anaerobic and aerobic systems.
Another factor in devising a training program
for alpine skiing is analyzing the muscles used in
this activity, and the type of contraction (i.e.,
static, dynamic, concentric, eccentric) that these
muscles typically perform during this sport. Electromyographic
(EMG) analysis can measure utilization
of various muscles during a specific activity.
Due to the difficulties of analysis in an alpine
environment, few studies have been published on
EMG activity during downhill ~kiing.".'~.~'
Of the three studies published, the one that is
most applicable to the purpose of this paper is
the Louie et al. study.27 They studied the gluteus
medius and maximus, biceps femoris, semitendinosus,
peroneus longus, and tibialis posterior
muscles. They noted that all these muscles were
active at various intensities during torsional movements
of the lower extremity in skiing. A great
need for more skiing EMG research is obvious.
Without EMG studies the best analysis of muscular
activity is a theoretical one in which, based
on the movements performed or the positions
maintained at each joint, estimates of the muscle
group most utilized are noted. Foss and Garrick16
have presented an excellent review of the muscles
used in downhill skiing. These muscles are
grouped according to the actions they perform
(Table 1).
The type of muscle contraction used in downhill
skiing varies and is partly dependent on the particular
muscle group studied and also on the
experience of the individual skier. Most of the
muscular analysis in downhill skiing has appropriately
centered on s t a t i ~ ' ~a,n*d~ d y n a m i ~ ' ~ . ~ ~ . ~ ~
quadriceps contractions. The quadriceps is the
muscle group that is most important to the skier
as it controls changes in the stiffness of the knee
in the sagittal plane. Static muscular contractions
may block the arterial transport of oxygen to the
muscle.25 By necessity, the muscle must then
resort to use of the anaerobic energy system.
With increasing skill, the contractions become
more dynamic and less ~ t a t i c .H~o~w.ev~e~r, the
static component is very important for all downhill
skiers. Its importance has been displayed by the
greater isometric quadriceps strength of downhill
skiers compared to athletes of various sport^.'*^'^
In the same sample of athletes, the quadriceps of
the skiers were not as strong as some of the
other athletic groups in dynamic contractions.
Other muscles besides the quadriceps must
also act both dynamically and statically. These
are the actions that are caused by muscles that
contract both statically and dynamically:
1) Trunk rotation
2) Trunk lateral flexion
3) Hip extension
4) Hip abduction
5) Hip adduction.
The predominantly static contractors result in:
1) Trunk flexion
2) Trunk extension
3) Ankle inversion
4) Ankle eversion
5) Ankle plantarflexion
6) Finger flexion.
Finally, the muscles that act predominantly in
the dynamic mode are those that account for the
following actions:
1) Hip rotation
2) Hip flexion
3) Arm extension
4) Elbow extension.
There are multiple classifications of dynamic
muscular contraction based on: 1) speed (fast
versus slow); 2) movement that occurs with the
contraction (eccentric versus concentric); and 3)
intensity (maximal versus submaximal). In downhill
skiing, contractions of the quadriceps are typ
ically of high intensity at slow velocity, and are
both concentric and eccentric.15 In sum, training
of the quadriceps should include both static and
slow dynamic exercise at high intensity with the
dynamic exercise taxing the muscle both concentrically
.and eccentrically. For the purposes of
this paper we will assume that the other dynamic
muscles function in a similar manner as the quadriceps,
i.e., slow velocity, high intensity eccentric
and concentric contractions. It is apparent that
more research is needed to assess the specific
modes of contraction of the other dynamic muscles.
Special demands are required of other systems
of the human body because of the high speeds
and forces inherent in alpine skiing. The neuromuscular
system must be trained for balance to
allow efficient movement down the ski slope and
to prevent falls. The skeletal system is taxed
heavily in ski falls and flexibility exercises are
necessary to allow adequate joint movement that
must occur in the high momentum/velocity falls.
While alpine skiing relies on both the aerobic
and anaerobic systems for energy production,
cross-country skiing requires, for the most part, a
430 MORRISSEY ET AL JOSPT Vol. 8, No. 9
TABLE 1
Muscles important in downhill skiing'
Action Musclds) Ski functionls)
1. Neck extension Spinalis Hold head position
2. Trunk flexion Rectus abdominus Hold ski position
lnitiate and block turning
3. Trunk extension Trunk extensors Hold ski position
4. Lateral trunk flexion Quadratus lum- Hold ski position
borum
5. Trunk rotation Sacrospinalis Initiate turning
Internal and external
obliques
6. Shoulder extension Posterior deltoid Poling
Latissimus dorsi Rising from fall
Teres major
Triceps brachii
7. Elbow extension Triceps brachii Poling
Rising from fall
8. Finger flexion Finger flexors Pole grasp
9. Hip extension Gluteals Pelvic thrust
Hamstrings Movement out of tuck
position
Holding ski position
10. Hip flexion Rectus femoris Return leg to ski posilliopsoas
tion
11. Hip adduction Adductor magnus, Hold legs together
longus, and
brevis
12. Hip abduction Gluteus medius Heel thrust
Tensor fascia latae
13. Hip rotation Hip internal and ex- Heel thrust
ternal rotators
14. Knee extension Quadriceps femoris Hold ski position
15. Ankle inversion Tibialis anterior and Edging
posterior
16. Ankle eversion Peroneals Edging
17. Ankle plantarflexion Triceps surae Hold ski position
Derived from Foss and Garrick.16
strong and efficient aerobic system. Although under
dispute, it has been noted that the aerobic
system is taxed more in uphill skiing than it is in
uphill treadmill r~nningH.~ay mes and Dickenson"
noted a greater maximal oxygen uptake in crosscountry
skiers as compared to downhill skiers. In
fact, Saltin and A ~ t r a n sdtu~d~ie d a large group of
athletes from different sports and noted that the
cross-country skiers had the greatest maximal
oxygen uptake. Even when maximal oxygen uptake
was considered relative to body weight, the
cross-country skiers were second only to marathon
runners.24
As mentioned previously, an alpine skier receives
approximately 65-7O0/0 of their energy
from the aerobic system. This is in contrast with
the estimated 95-1 00% reliance on the aerobic
system in cross-country skiing.24 Not only are
cross-country skiers able to reach high values for
maximal oxygen uptake, they are also able to
maintain high percentages of their maximal oxygen
uptake over long periods during skiing. Maintenance
of 80% of maximum oxygen uptake for
hours has been noted among cross-country
skier^.^ Therefore, there is little doubt about the
necessity for a strong and efficient aerobic system
to perform cross-country skiing at an enjoyable
level. On a competitive level, the ability to maintain
near maximum oxygen energy metabolism is a
major determinant of success when skill and lean
body mass are
Cross-country skiing requires concentric muscular
contractions that are less intense and of
higher velocity than those required in downhill
skiing. Thus, strengthening should emphasize exercises
that are faster in speed, greater in repetition,
and against smaller loads than those used in
downhill ski conditioning.
Although there are few EMG reports for downhill
skiing, there are even fewer concerning crosscountry
skiing. Hixsonl' has described the muscles
that are important in cross-country skiing.
JOSPT March 1987 SKI CONDITIONING 43 1
The muscles and their major functions in crosscountry
skiing are listed in Table 2. In general, the
muscles that are of greatest importance in providing
the power necessary for propelling the skier
are the extensors. They provide the pole thrust,
by rapid extension of the shoulder (posterior deltoid,
latissimus dorsi, teres major, and triceps
brachii) and elbow (triceps brachii), and the kick
by strong extension of the low back (trunk extensors),
hip (gluteals and hamstrings), knee (quadriceps),
and ankle (triceps surae).
SKI INJURIES
When devising an injury prevention program,
understanding the parts of the musculoskeletal
system most commonly injured during skiing and
the biomechanics involved in their mechanical failure
is important. Identifying and specifically
strengthening muscles that act to protect frequently
injured areas is vital in designing a conditioning
program.
Downhill ski injuries most frequently occur in
the lower extremity (versus the upper extremity,
spine, etc.). Table 3 describes the injury frequency
pattern for the major areas of injury in downhill
skiing. A 1982 survey of ski injuries noted that of
the total number of injuries, 27.8% occur at the
knee, and of Ithese, knee ligament injury is most
frequent (Table 4).19
The usual mechanism of knee ligament injury is
a fall that results in a knee valgus force, combined
with tibial external rotation." This usually occurs
when one ski becomes fixed or loses its parallel
alignment to the ski that is moving in the correct
direction. This type of injury is more common in
novice skiers who have a tendency to ski with
their legs spread apart in attempting to maintain
a wider, more stable base of support. These
combined forces may result in injury of the medial
collateral ligament (MCL), anterior cruciate ligament
(ACL), and one or both menisci. Medial
collateral ligament injury with or without ACL injury
represents 61.3% of the injuries.lg A possible
method of prevention for this frequent type of
injury is to strengthen the muscles of the leg that
act to assist these two ligaments in their function.
Stress on the MCL occurs with tibial external
rotation and valgus force. The q~adriceps,~'.~"
sartorius,30 and hamstrings3' may dynamically o p
pose knee valgus force, while the muscles comprising
the pes anserinus (semitendinosus, gracilis,
and sartorius), and the other medial hamstring
muscle, the semimembranosus, offer the
major opposition to tibial external rotation. Use of
resisted knee flexion, knee extension, and tibial
internal rotation will specifically strengthen the
hamstrings, quadriceps, and pes anserinus, respectively.
Lateral collateral ligament (LCL) and posterior
cruciate ligament (PCL) injuries occur less frequently
than MCL injuries. Injury to the LCL represents
4.2% of the knee injuries that occur during
skiing, while PCL injuries represent only 1 % (compared
to 61.3% for the MCL).lg Opposite to MCL
injury, LCL injury occurs with combined knee
TABLE 2
Muscles important in cross-country skiing
Action Muscle(s) ' Ski function(s)
1. Trunk flexion
2. Trunk extension
3. Scapular adduction
4. Shoulder extension
5. Elbow extension
6. Hip extension
7. Hip flexion
8. Knee extension
Rectus abdominus
Trunk extensors
Rhomboid major
and minor
Trapezius
Posterior deltoid
Latissimus dorsi
Teres major
Triceps brachii
Triceps brachii
Gluteals
Hamstrings
Rectus femoris
lliopsoas
Quadriceps
Double poling
Stable base
Stable base
Assist in kick
Poling
Poling
Poling
Kicking
Leg return after kick
Kicking
Hold ski position
Leg return after kick
Kicking
9. Ankle dorsiflexion
10. Ankle plantarflexion
Tibialis anterior
Triceps surae
JOSPT Vol. 8, No. 9
TABLE 3
Areas and percentage of the body injuries during downhill
skiing*
Area Percentage
Lower extremity 65
Upper extremity 29
Head and face 3
Chest 2
Back
Total
From Davis et aI.*
TABLE 4
Knee injuries in downhill skiing*
% of knee
injuries
Ligament sprains
Medial collateral with or without
anterior cruciate
"Isolated" anterior cruciate
Lateral collateral
Posterior cruciate or capsule
Complete dislocation
SUBTOTAL
Other knee injuries
Contusions
Possible tom menisci
Patellar: chondromalacia, pain, subluxation
Laceration
Tibial plateau fracture
Patellar fracture
SUBTOTAL
TOTAL
'10 of total
injuries
17.1
2.0
1.2
0.3
20.5
3.1
1.9
1.5
0.6
0.1
0.1
7.3
27.8
From Howe and Johnson.lg
varus force and internal tibial rotation. These
forces result when a skier catches the outside
edge of one ski, causing it to run across the other
ski. Aggin, this type of fall is more common in
novices. A strong tibial external rotation group
(the lateral hamstring-biceps femoris) as well as a
strong iliotibial band may aid in preventing excess
tibial internal rotation and knee varus. The biceps
femoris may be strengthened using resisted knee
flexion and tibial external rotation. The gluteus
maximus and tensor fascia latae, by way of the
iliotibial band, may be strengthened with resisted
hip abduction and extension.
Two other significant knee injuries that may be
prevented with proper conditioning are patellofemoral
dysfunction and derangement. Patellofemoral
dysfunction, for the purpose of this paper,
includes patellofemoral pain syndrome, patellofemoral
arthralgia, patellar tendinitis, parapatellar
pain, and iliotibial band inflammation. The iliotibial
band has been included in the classification because
of its attachment to the patella. One cause
of these disturbances is overloading of the patellofemoral
joint. Downhill skiing places great loads
on the patellofemoral joint as the skier maintains
a flexed knee position which requires a strong
quadriceps contraction.
Preventing patellofemoral dysfunction can be
best obtained by strengthening the quadriceps
musculature. A strong quadriceps is necessary
for proper function at the patellofemoral joint.
Resisted knee extension acts to strengthen the
quadriceps. In addition, hamstring and calf
stretching should also be performed to decrease
the load on the quadriceps in knee extension
activity. A flexible joint requires less energy to
move and can more further within its range.26,32
Antich et aL2 have noted that patients with patellofemoral
dysfunction had significantly tighter
hamstrings in the involved leg.
Patellar derangement includes patellar subluxation
and dislocation. Injuries of this type are often
confused with MCL injury for two reasons. First,
the mechanism of injury is the same for both
groups, i.e., knee valgus force combined with
tibial external rotation. Second, t6e area of pain
is in close proximity for each injury. In patellar
subluxation or dislocation, pain may be localized
at the stretched or torn medial retinaculum, while
in MCL injury pain may be located along the length
of the ligament. A program preventing patellar
derangement is, in essence, a combination of the
prevention program for MCL injury and patellar
dysfunction. Emphasis is placed on strengthening
the muscles preventing external tibial rotation,
and also on the quadriceps which control patellar
tracking.
Sprains may occur at the foot and ankle, but
these represent only 2% of the total number of
injuries.39 Tibial fracture is another injury that occurs
in downhill skiing and this represents 3.1%
of the total number of inj~ries.~F'r actures of this
type are becoming much less frequent in downhill
skiing.39
Two other lower extremity injuries that may be
prevented through an adequate conditioning program
are peroneal tendon subluxation and gastrosoleus
strains. Trevino and Alvarez3' described
peroneal tendon subluxation as "one of the most
overlooked skiing injuries." These authors reported
that this injury represents only 0.5O/0 of the
JOSPT March 1987 SKI CONDITIONING 433
total number of injuries, but warned that this may
actually be an underestimation. Regardless of the
frequency of this injury, we believe that a strong,
flexible peroneal muscle group may prevent this
type of injury. Strengthening of the peroneals may
be obtained through resisted ankle eversion and
foot plantarflexion exercises. Stretching of the
ankle into inversion and dorsiflexion will maintain
mobility of the peroneal muscle group. This
stretching is vital because a lack of full dorsiflexion
range of motion is important in the mechanism of
this injury, forward falling into ankle dorsifle~ion.~~
Forced dorsiflexion in a forward fall causing
peroneal subluxation is the same mechanism that
causes gastrocsoleus strains.39 To prevent injury
of this musculotendinous unit, resistive plantarflexion
and stretching into ankle dorsiflexion
should be performed to assure strength and flexibility,
respectively.
Though lower extremity injuries are the dominant
injuries in downhill skiing, injury also occurs
to the upper extremity. Upper extremity injuries
represent 25% of the total number of injuries that
occur in downhill skiing.' This compares with the
approximation of 60% that occur at the lower
extremity. Injury to the thumb accounts for over
one-third of the'upper extremity inj~ries.T~h' umb
injuries usually consist of ulnar collateral ligament
sprain. This typically results from a fall onto an
outstretched hand causing the thumb to be forced
into abduction and e~tension.~W' e suggest three
measures of prevention for this injury. First,
strengthening the thumb musculature to prevent
excessive extension and abduction should be performed
with ball squeeze exercises. Second,
proper instruction in correct falling using shouldertrunk
rolling may decrease the frequency of this
injury without exposing the shoulder, neck, and
head to injury. Finally, skiing without a strap may
be helpful in decreasing thumb injury.
In addition to thumb injury, the shoulder is
frequently injured representing approximately
one-fourth of the upper extremity inj~ries.~T'h e
most frequent of these is anterior shoulder subluxation
or dislocation. Injury of this type results
from a fall on an outstretched arm. To protect
against this injury again we advise a program of
stretching and strengthening as well as instruction
in shoulder trunk roll falling. An exercise program
focusing on strengthening the anterior shoulder
musculature may decrease anterior movement of
the humeral head in the glenoid fossa. Especially
emphasized is the subscapularis muscle since it
is a major anterior ~tabilizer.~T' his muscle may
be strengthened by resistive internal rotation. To
strengthen the other anterior shoulder musculature,
resistive shoulder flexion and horizontal adduction
should be performed. Aronen and Regan3
have presented the successful results of their
program of shoulder strengthening for prevention
of dislocation recurrence.
Besides shoulder musculature strengthening
we also suggest stretching of the shoulder joint
and musculature. A joint with normal flexibility
may be less likely to suffer derangement than a
hypomobile joint. At the same time a hypermobile
person should not increase mobility through
stretching. For skiing, the shoulder should be
stretched in the position that will offer enough
mobility for the most typical mechanical cause of
injury-external rotation and horizontal abduction
with the arm in 90° abduction.
Cross-country skiing, though growing at a rapid
rate, is still not as popular as downhill skiing. In
addition, the medical literature devoted to crosscountry
skiing compared to downhill is disproportionate.
For the sports medicine specialist, crosscountry
skiing differs from downhill skiing mainly
in the physiological demands and the smaller number
of injuries that occur with this type of skiing.
The major factor in both of these differences
results from the means of propulsion in each type
of skiing, i.e., downhill relies on gravity while
cross-country relies on self propulsion.
The rate of injury in downhill skiing has been
estimated to be from two to 26 times greater than
cross-country skiing.43 However, injuries do occur
in cross?country skiing and warrant detailed analysis.
Concern over cross-country skiing injuries can
be justified by the study of Jarvinen and ~annus~'
who noted in a group of ACL injured individuals
that 50% were injured cross-country skiing.
As in downhill skiing, the lower extremity is the
area most often injured in cross-country skiing.
Lower extremity injuries represent 61 % of the
injuries while approximately 26% are of the upper
extremity (compared to 60 and 25%, respectively,
for downhill skiing).42 Another study has noted
that 49% of the cross-country injuries are of the
lower extremity while 41% are of the upper extremity.'
Most of the injuries in cross-country
skiing occur when the individual is being propelled
by gravity down an incline. Fortunately, this type
of propulsion represents only a minor part of the
ski activity. The major force in propulsion is the
activity of the skier's musculature. As a result, the
Y ET AL JOSPT Vol. 8, No. 9
conditioning necessary for self propulsion differs
from the gravity propulsion program and the injuries
in gravity propulsion are more serious and
occur more frequently.
As one might expect, the mechanism of injury
during hilly descent in cross-country skiing also
mimics those occurring in downhill skiing, e.g., a
fall results in knee valgus and tibia1 external rotation,
thus injuring the medial collateral ligament.
Since the mechanisms of injury are similar to
those which occur in downhill injuries, the muscles
that require training to prevent injuries are similar
to those described in the downhill ski injury prevention
section.
MUSCULOSKELETAL CONDITIONING
PROGRAMS
Based on the information presented in the sections
on physiological demands and mechanisms
of injury, a specific conditioning program for the
musculoskeletal system may be devised. Below
is a description of two suggested programs, one
for downhill skiing and the other for cross-country
skiing. These are only suggested programs and
may serve as a framework for programs that have
modifications and additions to fit an individual's
needs or preferences.
The following programs should be performed
at least twice a week during the off-season and
more frequently-at least three times a weekduring
the ski season. Ideally, the workout program
will be divided into strengthening days and
endurance days to be performed on alternate
days for a total of 6 days per week with 1 day off
each week. For example, strengthening exercises
should be performed Monday, Wednesday, and
Friday while endurance exercises are performed
on Tuesday, Thursday, and Saturday with Sunday
as the day off. At the very least, the strength and
endurance sessions should each occur twice per
week.
For the strengthening exercises we have noted
successful results using a protocol of one to three
sets of 10 to 20 repetitions with a 1 minute rest
period between sets. At no time during the exercise
program should joint pain be experienced by
the athlete. Muscular "fatigue pain," i.e., burning
discomfort in the muscle during exercise, is allowed
and is actually a goal of the individual
exercise because this indicates that the muscle is
being taxed. Finally, the resistance used (or the
muscle tension elicited) should be the maximum
the muscle group can work against for the number
of sets and repetitions used. Resistance should
be increased whenever the muscle is not being
taxed to the fullest amount.
Cardiovascular endurance should be trained for
a minimum of 20 minutes at a level that causes
the heart rate to increase to at least 70% of its
maximum (equal to 220-age).29 If endurance training
is performed on the same day as the strengthening
program, it is suggested that the endurance
training occur prior to the strengthening to allow
the body to be more "warmed up" for the strengthening
exercises.
The endurance training should differ for downhill
skiers compared to cross-country skiers.
Downhill skiing usually consists of short high intensity
work punctuated by brief periods of rest
(while still on the slope going down) or longer rest
periods (chair lift return to top of slope). As a
result, brief, high intensity sprints should occur
throughout the training session. For cross-country
skiing, endurance training should be of longer
duration than the downhill ski endurance program.
Low intensity exercise, relative to the sprints used
for downhill skiing, should be employed.
DOWNHILL SKI PROGRAM
Combining the muscles importdnt in the downhill
ski activity with the muscles that may act in
musculoskeletal injury prevention, the specific exercise
for strengthening can be devised. In each
case a number of methods may be used to offer
resistance to the muscle group being exercised.
These will be divided into upper extremity, trunk,
and lower extremity exercises.
A. Upper Extremity
Resistance should be offered to the following
muscle groups.
1. Shoulder flexors. Performed dynamically to
increase their function in offering anterior stability
to the joint.
2. Shoulder extensors. Performed dynamically
to increase their function in poling and rising
from falls.
3. Shoulder internal rotators. Performed dynamically
to offer greater anterior shoulder stability.
4. Shoulder horizontal adductors. Performed
dynamically to offer greater anterior shoulder
stability.
5. Elbow extensors. Performed dynamically to
JOSPT March 1987 SKI CONDITIONING 435
increase their function in poling and rising
from falls.
6. Finger flexion. Perform ball squeezes for 5-
10 minutes at a time to protect against thumb
injury.
B. Trunk
1. Neck extensors. Performed statically to increase
their ability to hold the head position.
2. Trunk flexors. Performed dynamically to increase
their ability to hold the ski position
and to initiate and block turning.
3. Trunk extensors. Performed dynamically to
increase their ability to hold the skin position.
4. Trunk rotators. Best performed statically to
increase their ability to initiate turning.
5. Lateral trunk flexors. Performed dynamically
to increase their ability to hold the ski position.
C. Lower Extremity
1. Hip flexors. Performed dynamically to increase
their ability to return the leg to the
proper ski position.
2. Hip extensors. Performed dynamically and
statically gince this muscle group acts in both
modes during downhill skiing. Increased
strength of this muscle group may increase
its ability to function in pelvic thrust, movement
out of tuck position, and holding of the
ski position.
3. Hip adductors. Performed statically and dynamically
to increase their ability to hold the
legs together.
4. Hip abductors. Performed dynamically to increase
their ability in heel thrusting.
5. Knee extensors. Performed statically and dynamically
to increase its ability to hold the ski
position, offer knee stability against valgus
forces, and prevent patellofemoral pathology.
6. Knee flexors. Performed dynamically to offer
support to anterior and rotational knee stability.
7. Tibial internal and external rotators. Performed
dynamically to offer support to rotational
and valgus (sartorius) knee stability.
8. Ankle invertors. Performed statically to increase
their ability in edging.
9. Ankle evertors. Performed statically to increase
their ability in edging and prevention
of peroneal tendon subluxation.
10. Ankle plantarflexors. Performed statically to
increase their ability to hold ski position and
prevent gastrosoleus strains.
Stretching is another important facet of the ski
conditioning program. For optimal results and
safety we suggest static, musculature stretching
of 10-20 sec duration (except for trunk-2-4 sec
duration) repeated 10-15 times per position of
stretch. Light stretching should be performed before
workouts and restretching with stronger
force should be done immediately after the workout
while the muscle is "warmed up." Stretching
should be performed daily with or without the
strengthening exercises. The most important time
of the year for stretching is during the season,
especially on days when the individual is skiing.
Again, in these instances stretching should occur
before and after the skiing. In fact, periodic
stretching throughout the ski day is optimal.
Anderson1 has presented excellent illustrations
of stretching positions. The stretching positions
that are most important for the downhill skier are:
1. Shoulder external rotation with horizontal abduction.
Performed at 90' of shoulder abduction
in a supine position, this exercise will
increase the mobility of the anterior shoulder
joint and musculature.
2. Trunk flexion. This exercise stretches the posterior
back soft tissue.
3. Trunk extension. This exercise helps to maintain
the normal lumbar curvature.
4. Trunk rotation. This exercise offers added mobility
for trunk rotation that is vital to the turning
action of the skier.
5. Hip flexion with knee straight (hamstrings).
Thi$ exercise is important not only as a possible
prevention for patellofemoral problems
but also as a preventive measure for hamstring
muscle strains and tears.
6. Ankle dorsiflexion (calf). Should be performed
with the knee straight and with the knee bent
to emphasize stretching of the gastrocnemius
and soleus, respectively.
7. Ankle dorsiflexion (peroneals). Performed similar
to the soleus stretch except the foot should
be placed in a position of inversion to specifically
stretch the peroneals.
A final component of the downhill program is
an exercise that mimics the ski activity and will
increase the skier's balance, agility, and endurance.
The exercise, called the pillow jump, is
performed by standing parallel to a pile of pillows
or similar object and jumping sideways from one
side of the pillows to the other. As the exercise
436 MORRISSEY ET AL JOSPT Vol. 8, No. 9
becomes easier to perform, more jump repetitions ankle dorsiflexors should be performed. The knee
and a higher pile of pillows should be used. extensors are also important in holding the ski
position and this requires isometric exercise of
CROSS-COUNTRY SKI PROGRAM these muscles.
There are two major differences between the
downhill ski program and the cross-country ski
program. One of these differences has been described
previously, i.e., that the cardiovascular
endurance exercise of the cross-country skier
should be of longer duration and less intensity.
The second difference consists of the manner in
which the strengthening exercises are performed.
The cross-country skier should perform strengthening
exercises with more repetitions and less
resistance. This is done in order to mimic the
repetitive, lower intensity muscular contractions
of the cross-country ski activity.
Hixson,'' in his excellent text, has described
the muscles that are important in cross-country
skiing. Focusing on the muscles important in the
cross-country ski activity (Table 2) with the muscles
that may act in musculoskeletal injury pre-
The stretching program for the cross-country
skier is similar to the downhill skier's stretching
program with special emphasis on the following:
1. Triceps brachii/shoulder extensors. Performed
with the elbow and shoulder flexed to end
range.
2. Trunk. As described for the downhill ski program.
3. Buttocks. Performed in sitting with the leg
stretched across the abdomen with the knee
flexed.
4. Quadriceps/iliopsoas. Performed standing
with the knee in complete flexion and the hip
extended.
5. Hamstrings. As described for the downhill ski
program.
6. Gastrocnemius/soleus. As described for the
downhill ski program.
vention, a specific exercise strengthening proaram
mav be devised. The exercises devised to SUMMARY
Erevent iijury have been described in the downhill
program; therefore, only the exercises for the
muscles used in the cross-country ski activity will
be described. In each case a number of methods
may be used to offer resistance to the muscle
group being exercised. The exercises will be divided
into upper extremity, trunk, and lower extremity.
Exercise of the upper extremity focuses on
three muscle groups and their specific function in
poling. These three muscle groups are the shoulder
extensors, scapular adductors, and elbow
extensors. All exercise of these muscles should
be performed in a dynamic fashion.
Dynamic trunk exercises should be devised to
offer resistance to the flexors and extensors. The
flexors are important in double poling. The extensors
are important in assisting in the kick motion.
Both muscle groups are important in offering a
stable base of support to the continuously moving
extremities.
For the lower extremities exercise is centered
on the functional capacity of thigh and leg musculature
in kicking, leg return after kicking, and
holding the ski position. For kicking, dynamic resistance
exercise of the hip extensors, knee extensors,
and ankle plantarflexors should be performed.
For returning the leg after kicking, dynamic
resistance exercise of the hip flexors and
The popular sports of downhill and cross-country
skiing require proper conditioning and may
result in a number of musculoSkeletal injuries.
Injuries of this variety may be prevented by physical
conditioning of the skiing enthusiast in a yearround
program. We have presented a program
that may be useful in both clinical and training
settings as a method to enhance muscular endurance
necessary for increased enjoyment of the
skiing experience and to condition the musculoskeletal
system for the substantial demands required
of it during downhill and cross-country
skiing. Research is needed to determine the effectiveness
of conditioning programs such as this
in decreasing the prevalence of musculoskeletal
injury in sport.
The authors wish to thank Karen Kassa and Lillian Smith for their
assistance in manuscript preparation.
