Shin Splints From Ecs Conditions

¶ … Shin Splints From Ecs Conditions

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

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

The experimenter conducted simultaneous research of scientific literature for the purposes of confirming the initial assumptions about shin splint 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 experimenter determined that the source of the symptoms were more likely attributable to an alternate diagnosis; namely, to 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 foot 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 that are susceptible to Exertion-related 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 experimenter's symptoms in conjunction with a comparison of the symptoms described within the literature pertaining to shin splints and ECS-related pathology. More particularly, the experimenter recorded all apparent symptoms experienced during, immediately after, one day, and several days after exercise sessions. Those symptoms were then compared to the detailed symptomatology provided within the scientific literature pertaining to shin splints, Exertion-related Compartment Syndrome, and to the established criteria for differentiating between the two different types of ailments commonly affecting runners and other athletes and fitness enthusiasts.

Initial Symptom Awareness Stage

The experimenter began running in the fall of 2009, initially, on an outdoor running track. Almost immediately, the experimenter noticed acute pain 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 experimenter ignored the symptoms at first believing they were 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 (in the form of advice provided by 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 in-between successive exercise sessions, and evaluating the quality and proper fit of running shoes.

Anecdotal Information Collection and Informal Information Confirmation Stage

Prior to conducting a search for scientific literature, the experimenter attempted to follow the advice provided by experienced runners. Specifically, the experimenter cut back on the duration and distance of individual running sessions, increased the rest periods in-between successive running sessions, and invested in a higher quality pair of running shoes. The sales staff at the athletic footwear store concurred with the suspicions of the experienced runners and suggested that insufficient arch support, thickness and quality of the cushioning material, and imprecise fit of the experimenter's running shoes 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 also might be a contributing factor and indicated that the asphalt-based outdoor running track where the experimenter had been running was among the least forgiving surfaces in that it absorbs very little of the energy of foot-fall impact. In that regard, the salesman expressed optimism that the $120.00 running shoes the experimenter purchased would provide sufficient protection even on hard surfaces, but simultaneously suggested that the experimenter "look into some other types of surfaces" such as modern composite materials used on newer running tracks and natural surfaces such as grassy terrain.

In retrospect, the experimenter 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 (i.e. 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 potential conflicts on the realm of self-interest), the experimenter began implementing the advice prior to conducting a search for empirical research about shin pains associated with running and the informal concurrent diagnosis of "shin splints" from two independent lay sources.

Realistically, the main impetus for conducting further research for information was the persistence of the problem despite implementation of all of the elements of informal solutions suggested by experienced runners and retailers of running shoes. In that respect, the experimenter first tried changing running shoes, reducing the exercise session duration and distance run during each session, and increasing the rest period from one or two days to three (and then four and five) days in-between exercise sessions. Initially, the experimenter did not change the running surface variable but hoped optimistically that the other elements of the implemented changes would be sufficient to resolve the symptoms without changing the exercise venue.

Survey of Empirical Research on Shin Splints

The experimenter noticed that the changes in workout intensity, duration, and the substitution of footwear seemed to help resolve the symptoms only very moderately. Mainly, those changes merely delayed the onset of discomfort and delayed its escalation to the point of significant discomfort. After initial attempts to resolve the problem as described failed to do so, the experimenter began a search for empirical literature and other authoritative information on shin splints.

According to the available literature, the shin splints actually refers to medial tibial stress syndrome, a condition that has two principle causes: (1) micro-fractures within the tibial bone; and (2) irritation and inflammation of the periosteum tissue lining the tibia (AOS, 2009; NIH, 2007; Wilder & Sethi, 2004). Sports physiologists and orthopedic physicians report that runners vary considerably with respect to their physiology as well as with respect to the biomechanics of their running strides (AOS, 2009; NIH, 2007).

These variations can result in dramatically different exposure of various tissues to impact stress associated with running. In general, runners with poor biomechanics tend to achieve much higher vertical elevation in their strides as compared to better biomechanical strides that minimize vertical clearance between the soles of the feet and the running surface. In turn, the excessive elevation of poor running strides results in much greater impact forces transmitted through the foot and into the tibia; those forces can result in momentary spikes of the equivalent of more than four time the weight of the runner at the point of impact between the sole of the foot and the running surface (Wilder & Sethi, 2004).

The repetitive trauma from kinetic energy produced by shock and compressive loading during the impact phase of the running stride produces micro-fractures of the tibial bone that are initially asymptomatic. Continued exposure to the same stresses before the bone has had the chance to repair itself through the normal biological processes associated with bone cell generation and replacement results in larger cracks caused by the extension of microscopic fractures into one another resulting in medial tibial stress syndrome. The formation of periosteum irritation and inflammation is closely related to processes responsible for medial tibial stress syndrome except that the affected area is closer to the surface of the tibia and primarily affects the periosteum (Schissel & Godwin, 1999; Wilder & Sethi, 2004).

With respect to running, the empirical research into the factors responsible for both conditions include excessive repetitive trauma associated with any of the following elements of running, either alone or in various combinations: (1) poor running mechanics; (2) excessive foot pronation; (3) insufficient padding in footwear; and (4) excessively hard running surfaces (AOS, 2009; NIH, 2007; Wilder & Sethi, 2004).

Practical Research Finding Implementation and Experimentation Stage -- Phase I

The experimenter did not set out to determine specifically which of the various contributing factors (or combinations of factors) identified by the empirical research of medial tibial stress syndrome was most responsible for the experimenter's symptoms. However, since the initial attempts to resolve the symptoms incorporated changes to all of the external variables except a change in running surface, the experimenter immediately sought a softer running surface and temporarily abandoned running on any hard surface that magnified instead of minimized the physiological trauma associated with running on harder surfaces.

Because the empirical research also implicated poor running stride mechanics and excessive vertical elevation, the experimenter devoted considerable attention to making the following specific changes to the running stride: (1) shorter strides to minimize travel of the body while neither foot is in contact with the running surface; (2) conscious attempts to reduce vertical clearance to a minimum; and (3) increased surface contact of the sole and the running surface in a manner designed to decrease the magnitude of the highest spike in compressive load transmitted from the foot to the tibia on each foot-fall.

To reduce the risk of other injuries, such as ankle sprains, from uneven natural grass surfaces, the experimenter found an asphalt outdoor running track that was surrounded by a well-manicured grass field suitable for running on a soft but extremely uniform surface.

Unfortunately, none of these changes made a significant difference. Even the substitution of a much more forgiving natural running surface only further delayed the initial onset of symptoms and the increase of their intensity. However, the changes implemented by the experimenter were insufficient to allow the pursuit of running as a regular fitness activity because even with all of the changes implemented for the purpose of addressing the shin splint issues the symptoms recurred too soon and too intensely not to interfere with the activity.

As a last resort, the experimenter decided to try another anecdotal suggestion; namely, to try brisk walking or "power walking" on inclined surfaces such as naturally hilly terrain instead of running on flat surfaces. In principle, the idea is that brisk uphill walking provides many of the same cardiovascular and other physiological benefits of running, but eliminates the excessive trauma associated with the relatively high impact of foot-fall during a running stride.

A running stride necessitates that the exerciser leave the ground entirely and therefore, the high-impact nature of the activity cannot be eliminated entirely, even with perfect running stride mechanics; it can only be reduced. Conversely, a walking stride allows one foot to remain in contact with the surface at all times, and never requires that either limb bear the entire weight of the body without support from the opposite limb. It also dramatically reduces the mechanical loading and the intensity of the compression load spike associated with a running stride where each foot (and tibia) must bear the mechanical equivalent of several times the body weight on each stride (AOS, 2007; NIH, 2009).

However, the experimenter found that the symptoms actually increased from power walking on an inclined surface instead of decreasing.

As a result, the experimenter initiated additional searches for empirical research to identify additional possible solutions and to consider the possibility that the symptoms could be associated with alternate diagnoses. In fact, the experimenter managed to identify another major potential source of explanation for the physiological symptoms that related to a completely different aspect of physiology and biomechanics: Exertion-related Compartment Syndrome of the tibial fascia.

Survey of Empirical Research on Exertion-related Compartment Syndrome

Apparently, shin splints are frequently misdiagnosed because of the relative similarity in symptoms with another condition that is the result of entirely different physiological issues (Braver, 2002). According to the scientific literature, a system of muscles in the lateral anterior region of the tibia is responsible for the motion that allows the raising of the foot from the neutral position. Without these muscles, it would be impossible to walk or run efficiently because the foot would remain in the extended position at the end of each stride (Schissel & Godwin, 1999).

Like other muscles, the muscles in the anterior lateral region of the shin expand substantially during physical exercise as the result of engorgement with blood required to oxygenate those tissues and remove the buildup of lactic acid and other waste products produced in the physiological processes involved in repetitive muscular contraction during physical exertion (Mohler, Styf, Pedowitz, et al., 1997).

Also, much like other muscle systems, the set of muscles in the anterior lateral region of the tibia are bound together and encased in a compartment composed of a thin fibrous tissue sheath through which the muscles slide back and forth during physical exertion. In some individuals, there is insufficient room to accommodate the temporary increase in muscle volume associated with their increased size by virtue of engorgement with oxygenating blood volumes (Howard, Mohtadi, & Wiley, 2000; Mohler, Styf, Pedowitz, et al., 1997).

Because the biomechanical causes of shin splints and exertion-related compartment syndrome (ECS) are entirely different, the appropriate methods of reducing the factors responsible for the two conditions also differ tremendously. Whereas the symptoms associated with shin splints are most likely to respond to changes in exercise that reduces the exposure of the tibia to direct compressive loads and high impact under the weight of the athlete, the symptoms associated with ECS are most likely to respond to entirely different types of exercise adjustment and therapeutic modalities (Braver, 2002).

Moreover, ECS is not exclusively related to the tibial region as is generally the case with stress fractures, simply because other bones of the human anatomy are comparatively unlikely to be exposed to the types of repetitive impact and compressive loading in the manner that the running stride stresses the tibia. Stress fractures in the upper extremities, for example, are most often seen in laborers who use impact tools such as hammers and pneumatically powered mechanical equipment that transmit the mimetic forces of repetitive impact and/or vibrations to the user (Wilder & Sethi, 2004).

Exertion-related compartment syndrome is also commonly experienced by those who use their forearms in a manner that requires extended repetitive contractions, such as laborers who use hand tools, particularly those that require continual rotational exertion without the benefit of electrical or pneumatic assistance (Wilder & Sethi, 2004). In principle, the physiological phenomenon responsible is identical regardless of which particular group of muscles is involved: in all cases of ECS, the affected muscles become engorged with blood during the re-oxygenation and waste product removal process of repeated muscular contractions. Wherever the compartment formed by the fascia sheath surrounding those muscles provides insufficient space to accommodate the temporarily engorged muscle tissue, the resulting pressure causes considerable pain that is only capable of being reduced by cessation of the muscular contractions responsible for it (Mohler, Styf, Pedowitz, et al., 1997; Schissel & Godwin, 1999).

According to the literature, the fact that power walking up an incline surface dramatically increased the symptoms is a principal distinction between shin splints and ECS-related symptoms (Barver, 2002). Where symptoms are the result of shin splints, the substitution of brisk walking nearly always eliminates them, except where substantial inflammation still exists from previous exercise. However, unlike the symptoms associated with shin splints, the symptoms associated with ECS generally dissipate more quickly and are less likely to persist more than a day after the last exercise session.

Furthermore, walking (on a level surface) tends to cause pain where shin splints are involved because the irritation to the bone and/or to the periosteum produces sensitivity for several days following the most recent acute irritation to the area (Braver, 2002). Conversely, the symptoms associated with ECS tend to dissipate after the muscle tissues whose temporary engorgement is responsible for the condition as soon as those tissues return to their normal (i.e. un-engorged) condition (Mohler, Styf, Pedowitz, et al., 1997).

With respect to the differentiation of shin splints from ECS of the anterior tibial compartment is that the former is often associated with considerable tenderness to the touch in the medial in the inside (medial) region of the tibia whereas the latter is generally associated mainly with tenderness in the outside (anterior) portion of the lower leg. In addition, whereas the symptoms of shin splints persist and are often associated with tenderness to the touch several days after the most recent exercise session, the pain associated with ECS is only evident to the touch during and immediately after the exercise activity responsible for the irritation. Finally, as pertains to the differentiation of the two conditions, the symptoms of shin splints are produced by low-impact walking, even brisk walking on an inclined surface. Meanwhile, those associated with ECS in the anterior tibial compartment are dramatically increased by walking up an inclined surface, precisely because this motion exaggerates the range of motion of the foot and requires even more muscular contraction on each stride to return the foot to the starting position of the next stride (Mohler, Styf, Pedowitz, et al., 1997; Schissel & Godwin, 1999; Wilder & Sethi, 2004).

The first line of treatment for ECS problems in the tibial region is to implement the following procedures: (1) thorough stretching of the area prior to exercise; (2) deep tissue massage of the area in long downward strokes prior to exercise; (3) limitation in the duration of exercise sessions to the point where discomfort develops; (4) immediate application of cold compress or ice packs (cryotherapy); (5) analgesic medication to reduce inflammation (Howard, Mohtadi, & Wiley, 2000).

According to the literature, the purpose of the stretching and external stimulation (i.e. stretching) is to provide the tibial fascia an opportunity to expand as much as possible before the exposure to the muscular engorgement of the muscles it surrounds. Sometimes, the fascia compartment is capable of sufficient expansion to avoid ECS symptoms if it is given the opportunity to do so before the onset of the exercise that is responsible for producing ECS symptoms (Mohler, Styf, Pedowitz, et al., 1997; Schissel & Godwin, 1999). However, in all but the mildest cases, (again, unlike the situation with shin splints), it is impossible to resolve the symptoms of chronic ECS without surgery (Howard, Mohtadi, & Wiley, 2000).

Generally, ECS is definitively diagnosed through the use of intramuscular pressure sensors capable of measuring the buildup of pressure associated with muscular exertion. Typically, the device consists of a small needle probe that is inserted into the muscle and then any increases in pressure are measured as the athlete performs the exercises or motions though to be responsible for the symptoms (Howard, Mohtadi, & Wiley, 2000).