Research Review By Dr. Shawn Thistle©

Date Posted:

July 2009

Study Title:

Contributing factors to Medial Tibial Stress Syndrome: A prospective investigation

Authors:

Hubbard TJ, Carpenter EM & Cordova ML

Author's Affiliations:

Biodynamics Research Laboratory, Department of Kinesiology, University of North Carolina, USA.

Publication Information:

Medicine & Science in Sports & Exercise 2009; 41(3): 490-496.

Background Information:

Colloquially known as “shin splints” (we don’t use this term diagnostically anymore, right?), Medial Tibial Stress Syndrome (MTSS) is frequently encountered in clinical practice. Although MTSS is most commonly seen in runners, any athlete who participates in a ballistic sport is also at risk. Roughly 10-20% of runners will experience MTSS in their running career, and this condition represents up to 60% of overuse injuries seen in the leg (1).

MTSS generally presents diffuse shin pain along the medial border of the tibia (more focal pain may indicate a stress fracture) that is associated with activity (often a sudden increase in training volume). The tibial attachements of the soleus and tibialis posterior are most commonly involved, with tissue damage present at the enthesis or myotendious junction.

To date, no single cause has ever been isolated for MTSS, and both intrinsic and extrinsic factors are thought to contribute to its onset. The purpose of this prospective cohort study was to identify risk factors for developing MTSS in a group of college athletes. This knowledge could help manual therapists to mitigate patient risk by advising or treating patients accordingly as they participate in physical activity.

Most literature to date on MTSS has been conducted using military recruits, who can differ significantly from athletes in terms of training techniques, previous injury history, BMI, type of footwear, and so on. Therefore, the results of these studies cannot necessarily be applied to an athletic population, further supporting the need for this type of study.

Pertinent Results:

  • during the study, 29/146 subjects developed MTSS – most of these cases were from cross-country (14) and track and field (9) – the remaining cases were from volleyball (4) and soccer (2)
  • athletes with less than 5 years of running experience were more likely to develop MTSS (p = 0.002)
  • plantar flexion ROM was higher in MTSS subjects (p = 0.004)
  • athletes with a previous history of MTSS were more likely to develop MTSS (87% in MTSS group vs. 16% in healthy group, p = 0.0001), as were those with a history of stress fracture (p = 0.039) and those who used orthotics (p = 0.031)
  • a previous history of MTSS and number of years of running predicted group membership for 86.7% of the MTSS group and 86% of the non-MTSS (healthy) group
  • it should be noted that NO significant association was noted between developing MTSS and the number of miles/week, frequency of changing running shoes, vitamin use, and age of menstruation or birth control use for females

Clinical Application & Conclusions:

Running is an inexpensive and popular form of exercise. Further, most sporting activities include a running component. Therefore, the risk of developing MTSS is high in most active people. Manual therapists in all disciplines will attest that running provides us with a constant stream of new and recurring patients!

In this study – the following four factors were shown to be most important when attempting to identify athletes at risk for MTSS: plantar flexion ROM, running years, use of orthotics, and previous history or MTSS/stress fracture. Of these, a history of MTSS and number of years running were the most predictive of both MTSS development, and also remaining healthy. This emphasizes the importance of taking a proper history when evaluating athletes.

It is interesting to note the association found in this study between the use of orthotics and MTSS. This could mean one of two things – first, that use of orthotics may somehow contribute to MTSS development (this study was not designed to assess this relationship), or, that those in this study who had orthotics may have had a previous bout of MTSS or some other condition that warranted orthotic prescription. Overall, readers should not place too much emphasis on this finding at this time. Future research should investigate this relationship.

This study is in agreement with previous studies that indicate that people who experience one episode of MTSS are likely to get it again. This means that manual therapists may play a role in treatment and prevention of this condition. Anecdotally, a variety of soft tissue techniques (both manual and tool assisted), acupuncture, electromodalities, rehabilitation, and icing may be useful in treating this condition. Future research is needed on treatment modalities that can effectively manage MTSS, and reduce its recurrence.

Study Methods:

This study included 146 subjects (65 male, 81 female, average age ~20) who were healthy college athletes from Division I and II cross-country, tennis, soccer, volleyball, cheerleading, or track and field teams. Subjects had not sustained a lower extremity injury in the 6 weeks prior to the study.

Data was collected prior to each subject’s respective sporting season, and included demographic variables, as well as physical examination findings (including isometric ankle and foot strength, ROM, navicular drop, tibial varum). Subjects trained and competed as usual within their sport and were instructed to report any tibial pain to the study authors. If MTSS was deemed present (see below), the subject was allocated to the “symptomatic” group.

For this study, MTSS was diagnosed if the following conditions were met:
  • pain is not caused by ischemic conditions or stress fractures
  • pain must be a result of exercise and last for hours after exercise
  • no symptoms of numbness or nerve compression in the leg
  • pain located in a general area larger than 5cm on the posteromedial border of the tibia
  • diffuse discomfort noted with digital palpation of the distal third of the tibia
  • the posteromedial edge of the tibia could be uneven during palpation
Statistical analysis included independent t-tests/Chi-square analysis to determine whether significant differences existed between MTSS and non-MTSS subjects on continuous/discrete dependent variables, respectively.

Study Strengths/Weaknesses:

This study included data from a group of athletes in various sports. It was simple in its design and employed appropriate statistical techniques.

Only 29 subjects developed MTSS during the study – the results would be strengthened somewhat if this number was larger.

Additional References:

  1. Couture CJ & Karlson KA. Tibial stress injuries. Phys Sportsmed 2002; 30: 29-36.
  2. Association between foot type and tibial stress injuries: A systematic review. Br J Sports Med 2008; 42: 93-98.