Physical Training Dec 2004

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Water Works: Running Injuries II

Copyright Michael Moon © 2004 all rights reserved
Mike Moon, Deep Water Exercise
Mike Moon, founder of
Deep Water Exercise
Sport Medicine and Injury Rehabilitation: Running Injuries

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


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

For more columns check out the column archives.

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:

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Physical Training Dec 2004