Physical
Training
Dec 2004
Water Works: Running Injuries II
Copyright Michael Moon © 2004 all rights reserved
Mike Moon, founder of
Deep Water Exercise
Last issue we introduced this series of articles with an overview of
the stresses that result from running on land and the injuries that
very often result. Let us now consider the first of these injury
categories, stress reactions and/or fractures.
Stress Reactions and Fractures
The injury category most frequently associated with distance running is
stress reactions or the more advanced stage of injury known as stress
fractures. The initial stage of injury in this category would be
known as a stress reaction found somewhere on the skeletal frame.
A more precise description of this reaction would be periostitis.
This indicates that the outer lining of the bone known as the
periosteum has become inflamed due to a repeated overstress that has
been localized to that area. This may present as a dull ache in a
general area, and/or tenderness on palpation of the affected
area. It is at this stage that minor modifications in training or
equipment in combination with basic therapy for inflammation and
compensatory muscle strengthening that the injury can be eliminated in
short order. However if the injury is not properly diagnosed and
treated at this early stage it may progress to be a more serious stress
fracture.
A stress fracture is a result of continued overstress on the skeletal
frame beyond the stage at which periostitis is present. Due to
this continued overstress the bone is unable to remodel itself at a
pace necessary to maintain its integrity. As the stress proceeds
it becomes more and more localized leading to micro-fractures in the
bone itself (stress reaction stage). Eventually these
micro-fractures will grow closer and in number such that a complete
fracture of the bone will occur. In the most severe cases an
actual displaced fracture could result, but cases of this magnitude are
the extreme exception. The pain of continued activity will
usually stop the overstress before the injury becomes that
severe. In fact the site of a displaced stress fracture occurring
is most probable in the neck of the femur. This being the major
weight bearing bone in the body it is highly susceptible to complete
fracture if a stress fracture is present in this area. The
greatest precaution should be taken and complete non-weight-bearing
should be prescribed immediately for an injury of this nature.
The most common sites for stress reactions and fractures to occur in
runners are as follows; Tibia, Fibula, and Metatarsals. In a
review of 180 cases of stress fractures seen at a sports medicine
clinic in Australia the distance runners presented with over 42% of
their stress fractures in the Tibia. The most frequent stress
fracture site for track runners in this particular review was the
tarsal navicular at 35%. The following table, taken from this
review, shows the percentage distribution of stress fracture sites from
the four sports that presented with the most stress fractures.
| Site |
Track(n=54) |
Distance(n=35) |
Dance(n=32) |
Aus.Football(n=14) |
| Metatarsal |
16.7 |
14.3 |
56.3 |
14.3 |
| Tibia |
25.9 |
42.9 |
3.8 |
21.4 |
| Fibula |
9.3 |
22.9 |
21.9 |
21.4 |
| Tarsal navicular |
35.2 |
2.9 |
0 |
14.3 |
| Pars interartic. |
1.9 |
0 |
9.4 |
0 |
| Femur shaft |
1.9 |
5.7 |
0 |
0 |
| Talus |
1.9 |
0 |
3.1 |
7.1 |
| Pubic bones |
1.9 |
5.7 |
3.1 |
0 |
| Calcaneus |
1.9 |
5.7 |
0 |
7.1 |
| Sesamoid |
1.9 |
0 |
3.1 |
0 |
| Patella |
0 |
2.9 |
0 |
0 |
| Toe phalanx |
1.9 |
0 |
0 |
0 |
| Media malleol. |
0 |
0 |
0 |
7.1 |
| Femur-neck |
0 |
0 |
0 |
7.1 |
Prevention
The single most important factor in prevention of injuries in the
stress reaction/fracture category would be appropriate modification of
training regimens. Injuries of this nature most often present
themselves when the runner increases the intensity or quantity of
training too quickly, hence the saying “too much, too fast”. A
general rule for increasing training load is, no more than 10% per
week. This may be a bit conservative for some well conditioned
athletes but straying very much from this rule is more likely to lead
to injury than great performance improvements in the short term.
Mechanics are the next factor that should be considered. If the
individual runner has a specific bio-mechanic abnormality such as over
pronation, the proper steps must be taken to correct this
problem. Excessive pronation causes inordinate rotational stress
to be placed on the bones of the lower leg, as well as greater impact
forces being taken up by the small bones of the foot. In
addition, “excessive pronation overloads the medial soleus which may
repetitively fatigue the posteromedial tibia” leading to a stress
fracture. A quality motion control shoe may be all that is
required, however in severe cases an in-shoe orthotic device may be
necessary.
Another contributing problem is often muscular weaknesses or
imbalances. This would create a situation where an inordinate
amount of impact stress is directed to a small localized area, or
stronger muscle actions are not being offset by their anatomical
antagonists. A basic knowledge of anatomy and running mechanics
tell us which muscles are being strengthened through running itself and
which ones are not. The distance runner therefore should perform
exercises which will strengthen the muscles not being used as primary
movement units during running, but that work to support the integrity
of the movement. The most important of these muscles or groups of
muscles would be the anterior muscles of the lower leg, specifically
the anterior tibialis. This particular muscle is not worked
concentrically in any regularly performed activity. The runner
must therefore perform an exercise of dorsal flexion against
resistance. This is easily done with a rubberized band of some
sort such as a bicycle tire tube. The importance of strengthening
this particular area for the distance runner can not be emphasized
enough. The calf muscles are used dynamically during running and
the force that they generate on the skeletal structure is
significant. If the anterior muscles are weak they can not offset
this force and an excessive amount of torque is placed on the bone by
the posterior muscles, initiating inflammation of the periosteum and a
corresponding stress reaction. In addition to the above problem,
a weakness in the anterior muscles of the lower leg means that more of
the impact forces generated through running are transferred directly to
the bone. The bone most directly affected by this weakness being
the tibia, which again explains why the majority of stress fractures in
distance running occur in the tibia. If the anterior muscles are
strengthened they act to decelerate the dorsal flexion which occurs on
impact with the ground, thereby absorbing much of this impact stress
which would otherwise be taken up by the bone.
Another area that must be given consideration is the nutritional status
of the athlete, especially if this is a recurrent problem.
Athletes that are not taking in adequate amounts of the vitamins and
minerals that insure proper bone regeneration are setting themselves up
for injuries of this nature. It is especially important to
consider this possibility with female athletes due to a much higher
presence of eating disorders than with the male population.
“Women have a higher incidence of stress fractures than men and
amenorrhoeic athletes with decreased bone density are particularly at
risk. The female athlete triad consists of disordered eating,
amenorrhoea and osteoporosis”.
Treatment and Rehabilitation
The immediate response for treatment of injuries in the stress
reaction/fracture category should always be to reduce or eliminate the
offending activity. In this case that activity would be
running. Indeed this would be the most important first response
to all of the most common running injuries. However, due to the
nature of the sport and the mindset of its participants this is also
the least desirable solution for most individuals. The last thing
runners want to do is stop running!
In some situations it is appropriate to simply reduce the intensity or
quantity of the running being performed. If the problem is
detected at an early stage of its development (periostitis) the first
step would be to reduce the training load and make an assessment of the
other factors possibly contributing to the problem (see prevention).
If the injury has reached the more advanced stage of a full stress
fracture than complete non-weight bearing must be implemented.
The duration of this non-weight bearing period can vary greatly, from
as little as 2 weeks up to 16 weeks or more depending on the severity
of injury, the location of the injury, and the health status of the
athlete themselves. In a very small number of cases, complete
immobilization of the injured area is recommended. This again is
determined by many factors, including the injury site, the severity of
the injury, as well as the mindset of the individual athlete. The
treating physician may in some extreme cases feel that the only way in
which to stop the athlete from continuing to aggravate the injury is
through cast immobilization. Casting of the injured athlete may
also be recommended when the stress fracture presents in the femur
where a complete displacement fracture is a possibility. With
stress fractures of the most common nature however, cast immobilization
is not only unnecessary it is also not recommended. There are
many cross-training activities that the injured athlete can participate
in, that would not be possible if they were wearing a cast. Once
the athlete has begun the non-weight bearing, the next step is to
determine the cause of the injury. As with most injuries it is
often a complex interplay of factors that lead to the onset of the
injury. An accurate determination of what the contributing
factors were, needs to be made in order to prevent the injury from
recurring in the future.
Maintaining Fitness
Maintenance of fitness parameters during the period of rehabilitation
is of primary concern to both the injured athlete and the coach.
The higher the level of fitness the athlete can retain during the time
that they are unable to run, the less time it will take to return to
pre-injury performance levels. The activity of choice for the
running athlete should be deep water running. This is a
completely non-weight bearing activity that most closely replicates the
activity of running on land.
“Cross-training is very important during the rehabilitation
period to maintain aerobic conditioning. Pool-running has the
greatest carry-over for the distance runner”. If performed
optimally, following known training guidelines and individual fitness
parameters and performed with proper technique, close to 100 percent of
the individual's land running performance variables can be maintained,
even over a prolonged period of non-weight bearing
rehabilitation. In a case study of a distance running athlete,
suffering from a right foot Jones Fracture which required cast
immobilization for 14 weeks, it was determined that close to 100
percent of the performance variables were maintained through a program
of deep water running.
The benefit to the injured athlete, of any cross-training activity, is
directly related to how closely the activity corresponds to their
regular training regimen. This follows the rule of sport
specificity. The cross-training activity of swimming for example
bares little relation to the activity of running, due to the different
muscular demands. Swimming therefore is a poor choice of
activities for the injured runner. Cycling is a somewhat more
specific activity for runners with a relatively good carry over
effect. Weight training during a period of injury can often
provide long term benefits. Muscular weaknesses and imbalances
that may have even contributed to the injury should be addressed at
this time if possible. Cross-country ski machines and stair
climber machines may prove beneficial as well. All of these
cross-training activities have some cross over effect for the runner
and do provide variety to the training. As stated previously
though, deep water running has by far the greatest carry over effect
for the injured runner. A comprehensive description of Deep Water
Exercise/Running will be provided at the end of this series of articles.
Next Issue: Achilles Tendinitis
Mike Moon has a M.Ed in
Coaching (UVIC) B.PHED, BA,
B.ED (UBC) and
has been Assistant Coach of UBC Track and Cross Country for 15 years.
He
is also Head Coach, St. Georges Junior School Track and Field Program.
He has developed the Deep Water Exercise
program
which is used by elite level and professional athletes for
rehabilitation
and training. Mike continues to compete at the Masters level (in
distances
from 5000m to the marathon).
His website is: http://www.deepwaterexercise.com/
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