Identifying Factors That Contribute to Adolescent Bony Stress Injury in Secondary School Athletes: A Comparative Analysis With a Healthy Athletic Control Group.

BACKGROUND: Bony stress injuries (BSIs) are common among adolescents involved in high school sports. A better understanding of factors that contribute to adolescent BSI is needed to target preventative measures. HYPOTHESIS: Individuals who suffer a BSI will demonstrate significant differences in training methods, sleep, diet, and history of injury compared with a healthy, noninjured control group. STUDY DESIGN: Descriptive epidemiologic study. METHODS: Data from the National High School Stress Fracture Registry (NHSSFR), an internet-based adolescent BSI survey, were used to identify variables reported with adolescent (13-18 years of age) BSI. These findings were compared with a survey of 100 (50 males, 50 females) healthy athletic controls to identify significant differences between healthy adolescents and those with BSI. RESULTS: A total of 346 stress fractures were reported in 314 (206 females, 108 males) athletes within the NHSSFR. Comparison with healthy control participants demonstrated multiple significant findings. In particular, body mass index was significantly lower for patients with BSI injury compared with controls (P < 0.001). Patients slept significantly less than the control group (7.2 vs 7.95 hours; F = 34.41; P < 0.001). Females also slept significantly less hours than males (7.2 vs 7.63 hours; F = 11.02; P < 0.001). Fifty-eight percent of those who reported a BSI did not engage in any weight training. Those with a BSI had significantly higher average stress ratings than control participants (1.67 vs 1.42; P < 0.001), and females also rated their stress levels significantly higher than males (1.8 vs 1.38; P < 0.001). A significant difference between patients with any BSI and control participants existed for history of "shin splints" (Pearson χ2 = 28.31; P < 0.001), and females also expressed having shin pain lasting for longer than 4 weeks (Pearson χ2 = 8.12; P < 0.001) and more often (Pearson χ2 = 5.84; P = 0.02) than males. There was also a significant difference between patients with BSI and control subjects regarding dairy intake (2.25 vs 2.69; F = 6.43; P = 0.01). CONCLUSION: Findings revealed significant differences between those who reported a BSI relative to healthy athletic adolescents. These differences included body mass index, prior history of shin splints, involvement in weight training, amount of sleep, daily stress, and dairy intake. Preventive measures should be developed to address these areas to reduce the incidence of BSIs in the adolescent population.

Gender differences of muscle and crural fascia origins in relation to the occurrence of medial tibial stress syndrome.

Although women reportedly have a higher prevalence of medial tibial stress syndrome (MTSS) than men, the possible role of gender-based anatomical differences has not been investigated. The aim of the present study was to investigate the presence of gender-based differences in the range of muscle attachments along the entire medial tibia, the proportion of muscle attachment at the middle and distal thirds of the medial margin of the tibia, the structure of the crural fascia, and chiasm position. The specimens were 100 legs of 55 Japanese cadavers. Statistical analysis was carried out using a chi-square test to compare anatomical features between the sexes. The flexor digitorum longus (FDL) had a higher proportion of attachment to the middle and distal thirds of the medial margin of the tibia than the soleus (SOL; P < 0.001). The proportion of the SOL attachment to the middle and distal thirds of the medial margin of the tibia was 33.3% in men and 72.5% in women (P < 0.001). The soleal aponeurosis was not observed in any specimen. In all specimens the FDL formed the top layer of both chiasms. These results suggest that the higher prevalence of MTSS reported among women may be the result of gender-based anatomical differences.

Gait retraining and incidence of medial tibial stress syndrome in army recruits.

PURPOSE: Gait retraining, comprising biofeedback and/or an exercise intervention, might reduce the risk of musculoskeletal conditions. The purpose was to examine the effect of a gait-retraining program on medial tibial stress syndrome incidence during a 26-wk basic military training regimen. METHODS: A total of 450 British Army recruits volunteered. On the basis of a baseline plantar pressure variable (mean foot balance during the first 10% of stance), participants classified as at risk of developing medial tibial stress syndrome (n = 166) were randomly allocated to an intervention (n = 83) or control (n = 83) group. The intervention involved supervised gait retraining, including exercises to increase neuromuscular control and flexibility (three sessions per week) and biofeedback enabling internalization of the foot balance variable (one session per week). Both groups continued with the usual military training regimen. Diagnoses of medial tibial stress syndrome over the 26-wk regimen were made by physicians blinded to the group assignment. Data were modeled in a survival analysis using Cox regression, adjusting for baseline foot balance and time to peak heel rotation. RESULTS: The intervention was associated with a substantially reduced instantaneous relative risk of medial tibial stress syndrome versus control, with an adjusted HR of 0.25 (95% confidence interval, 0.05-0.53). The number needed to treat to observe one additional injury-free recruit in intervention versus control at 20 wk was 14 (11 to 23) participants. Baseline foot balance was a nonspecific predictor of injury, with an HR per 2 SD increment of 5.2 (1.6 to 53.6). CONCLUSIONS: The intervention was effective in reducing incidence of medial tibial stress syndrome in an at-risk military sample.

Incidence and risk factors for medial tibial stress syndrome and tibial stress fracture in high school runners.

PURPOSE: Medial tibial stress syndrome (MTSS) and tibial stress fracture (SF) are common lower leg disorders in runners. A prospective study was done to identify the incidence of MTSS and SF in high school runners and to determine risk factors. METHODS: A total of 230 runners participating in high school running teams were evaluated. All runners aged 15 years as first grade of high school were involved in the study. They were followed up for 3 years. The measured items included height, weight, body mass index (BMI), range of hip and ankle motion, straight leg raising (SLR), intercondylar and intermalleolar interval, Q-angle, navicular drop test, hip abductor strength and physical conditioning. Each runner was followed for 3 years to report occurrence of MTSS and SF. RESULTS: A total number of 102 MTSS (0.29 athlete exposures) and 21 SF (0.06 athlete exposures) were identified. In females, BMI significantly increased the risk of MTSS after adjustment for the other variables in this study (adjusted odds ratio, 0.51; 95 % confidence interval, 0.31-0.86). Increased internal rotation of the hip significantly increased the risk of MTSS (adjusted odds ratio, 0.91; 95 % confidence interval, 0.85-0.99). In males, limited SLR also significantly increased the risk of SF with adjustment for the other variables in this study (adjusted odds ratio, 1.38; 95 % confidence interval, 1.04-1.83). CONCLUSION: A significant relationship was found between BMI, internal hip rotation angle and MTSS in females, and between limited SLR and SF in males. LEVEL OF EVIDENCE: Prospective cohort study, Level II.

What are the main running-related musculoskeletal injuries? A Systematic Review.

BACKGROUND: Musculoskeletal injuries occur frequently in runners and despite many studies about running injuries conducted over the past decades it is not clear in the literature what are the main running-related musculoskeletal injuries (RRMIs). OBJECTIVE: The aim of this study is to systematically review studies on the incidence and prevalence of the main specific RRMIs. METHODS: An electronic database search was conducted using EMBASE (1947 to October 2011), MEDLINE (1966 to October 2011), SPORTDiscus(1975 to October 2011), the Latin American and Caribbean Center on Health Sciences Information (LILACS) [1982 to October 2011] and the Scientific Electronic Library Online (SciELO) [1998 to October 2011] with no limits of date or language of publication. Articles that described the incidence or prevalence rates of RRMIs were considered eligible. Studies that reported only the type of injury, anatomical region or incomplete data that precluded interpretation of the incidence or prevalence rates of RRMIs were excluded. We extracted data regarding bibliometric characteristics, study design, description of the population of runners, RRMI definition, how the data of RRMIs were collected and the name of each RRMI with their rates of incidence or prevalence. Separate analysis for ultra-marathoners was performed. Among 2924 potentially eligible titles, eight studies (pooled n = 3500 runners) were considered eligible for the review. In general, the articles had moderate risk of bias and only one fulfilled less than half of the quality criteria established. RESULTS: A total of 28 RRMIs were found and the main general RRMIs were medial tibial stress syndrome (incidence ranging from 13.6% to 20.0%; prevalence of 9.5%), Achilles tendinopathy (incidence ranging from 9.1% to 10.9%; prevalence ranging from 6.2% to 9.5%) and plantar fasciitis (incidence ranging from 4.5% to 10.0%; prevalence ranging from 5.2% to 17.5%). The main ultra-marathon RRMIs were Achilles tendinopathy (prevalence ranging from 2.0% to 18.5%) and patellofemoral syndrome (prevalence ranging from 7.4% to 15.6%). CONCLUSION: This systematic review provides evidence that medial tibia stress syndrome, Achilles tendinopathy and plantar fasciitis were the main general RRMIs, while Achilles tendinopathy and patellofemoral syndrome were the most common RRMIs for runners who participated in ultra-marathon races.

Biomechanical and lifestyle risk factors for medial tibia stress syndrome in army recruits: a prospective study.

Medial tibial stress syndrome (MTSS) is a common injury in active populations and has been suggested to be a result of both biomechanical and lifestyle factors. The main aim of this study was to determine prospectively whether gait biomechanics and lifestyle factors can be used as a predictor of MTSS development. British infantry male recruits (n=468) were selected for the study. Plantar pressure variables, lifestyle factors comprising smoking habit and aerobic fitness as measured by a 1.5 mile timed-run were collected on the first day of training. Injury data were collected during the 26 week training period and incidence rate was 7.9% (n=37). A logistic regression model for membership of the MTSS and non-MTSS groups was developed. An imbalance in foot pressure with greater pressure on the medial side than on the lateral side was the primary risk factor. Low aerobic fitness, as deduced from a 1.5 mile timed-run and smoking habit were also important, but were additive risk factors for MTSS. In conclusion, "poor" biomechanics were the strongest predictors of MTSS development but lifestyle factors were also important. The logistic regression model combining all three risk factors was capable of predicting 96.9% of the non-injured group and 67.5% of the MTSS group with an overall accuracy of 87.7%. While the model has yet to be validated against an external sample and limitations exist with regards to the quality of the data collected, it is nonetheless suggested that the combined analysis of biomechanical and lifestyle factors has the potential to improve the prediction of MTSS.