Shin Splints vs. Exertional Compartment Syndrome in Runners

Introduction and Background

This paper details the personal experiences of the author in identifying the source of physiological symptoms triggered by sports and fitness activities involving running or extensive (i.e., fast-paced and/or long-distance) walking. The author experienced significant discomfort in a localized region of both shins associated with running as a physical fitness activity. Anecdotal information based on advice from more experienced runners suggested that the problem related to the early formation stages of "shin splints," a colloquial term for micro-fractures in the tibia caused by repetitive impact stress from running-type activity.

To resolve the problem, the author attempted to identify its cause. In connection with this, footwear was changed to address potential causes attributable to dampening the intensity of repetitive foot-fall impact. When the problem persisted, the author attempted to vary the running surface to further reduce any physiological stress that was a function of impact intensity with harder running surfaces.

The author conducted simultaneous research of scientific literature to confirm the initial assumptions about shin splints and to identify other possible causes in the event that the symptoms were associated with alternate physiological issues possibly requiring different solutions. In fact, the author determined that the source of the symptoms was more likely attributable to an alternate diagnosis: namely, the buildup of intramuscular pressure within the anterior lateral compartment of the tibialis muscles.

More specifically, the muscles involved in raising the foot at the conclusion of each individual stride run along the front of the shin bone. They are encased within a thin sheath composed of fascia tissue, as is typical of muscle systems and their attachments throughout the body. As in the case of other areas susceptible to Exertional Compartment Syndrome (ECS) — such as the muscles of the forearms — ECS in the tibial area is caused by insufficient space within the fascia sheath to allow for normal expansion of the muscle during strenuous athletic activity involving those muscle systems. The differentiation of shin splints and chronic ECS problems is crucial because they are distinct conditions with different mechanical causes and, therefore, substantially different methods of treatment most conducive to their resolution.

Methodology

In principle, the methodology consisted of a relatively long-term process of recording the author's symptoms in conjunction with a comparison of those symptoms against descriptions found in the literature pertaining to shin splints and ECS-related pathology. More particularly, the author recorded all apparent symptoms experienced during, immediately after, one day after, and several days after exercise sessions. Those symptoms were then compared to the detailed symptomatology provided within the scientific literature pertaining to shin splints, exertional compartment syndrome, and the established criteria for differentiating between the two different types of ailments commonly affecting runners and other athletes and fitness enthusiasts.

Initial Symptoms and Anecdotal Diagnosis

Initial Symptom Awareness

The author began running in the fall of 2009, initially on an outdoor running track. Almost immediately, acute pain was noticed in the front (anterior) outside (lateral) portion of the lower leg in the upper region of the tibial bone. The discomfort consisted of a dull ache that increased in intensity with continued running but subsided substantially afterwards. The symptoms were ignored at first, as they were believed to be simply a variation of ordinary aches and pains often caused by athletic activity, particularly in persons who are not accustomed to those activities.

Anecdotal information from more experienced runners suggested that the symptoms were functions of a phenomenon called "shin splints," a colloquial reference to small fractures developing in the tibial bone itself. Informal advice consisted of decreasing the distances run in each exercise session, increasing the rest and recuperation periods between successive sessions, and evaluating the quality and proper fit of running shoes.

Anecdotal Information and Informal Confirmation

Prior to conducting a search for scientific literature, the author attempted to follow the advice provided by experienced runners. Specifically, this involved cutting back on the duration and distance of individual running sessions, increasing rest periods between successive sessions, and investing in a higher-quality pair of running shoes. The sales staff at the athletic footwear store concurred with the experienced runners' suspicions and suggested that insufficient arch support, inadequate cushioning, and imprecise fit were contributing to excessive impact forces associated with each foot-fall of the running stride.

Additionally, the store personnel suggested that the choice of running surface might also be a contributing factor, noting that the asphalt-based outdoor running track was among the least forgiving surfaces because it absorbs very little of the energy of foot-fall impact. The salesman expressed optimism that the new running shoes would provide sufficient protection even on hard surfaces but simultaneously suggested that the author consider softer surfaces such as modern composite materials used on newer running tracks or natural surfaces such as grassy terrain.

In retrospect, the author should have conducted at least a preliminary search for available empirical research on shin splints before relying on information from any individual whose obvious self-interest — in this case, retail sales — could have accounted for potentially biased information. However, because the information provided by the retail sales personnel matched the anecdotal information supplied by the experienced runners (which presumably did not reflect any conflicts of self-interest), the author began implementing the advice prior to conducting a search for empirical research on the informal concurrent diagnosis of "shin splints" from two independent lay sources.

Realistically, the main impetus for conducting further research was the persistence of the problem despite implementing all of the elements of the informal solutions suggested by experienced runners and retailers. The author first tried changing running shoes, reducing exercise session duration and distance, and increasing the rest period from one or two days to three, then four and five days between sessions. Initially, the running surface variable was not changed, in the hope that the other implemented changes would be sufficient to resolve the symptoms without changing the exercise venue.