Stress Fractures In Women Research Articles

Physiological Factors of Female Runners With and Without Stress Fracture Histories: A Pilot Study.

Female runners are at increased risk of stress fractures (SFs) compared with men. Literature is lacking with regard to best practice for preventing and treating SFs in women. The purpose of the study was to compare physiological measures and running-related factors between women of various ages and running abilities with and without a history of running-related SFs. Women with and without SF histories will differ with regard to medical and menstrual history, bone health, body composition, nutrition, and running history. Prospective cohort study. Level 2. A total of 20 female runners with SF histories were matched based on age and running distance with 20 women without SF histories. Data included medical, menstrual, running, injury, and nutritional histories; blood histology related to nutritional, hormonal, and bone-related risk factors; and bone density, fat, and lean tissue using dual energy x-ray absorptiometry. Paired t tests were used to examine differences between women with and without SF histories, and Spearmen correlations were conducted to examine relationships between physiological factors. Women with SF histories had lower hip bone mineral density compared with women without SF histories (P < 0.05). SF history was moderately correlated with menstrual changes during increased training times (r = 0.580; P < 0.0001) but was not correlated with any other physiological factor. There was a moderate correlation within the SF group (r = 0.65; P = 0.004) for bone markers for resorption and formation both increasing, indicating increased bone turnover. Female runners with low hip bone mineral density, menstrual changes during peak training, and elevated bone turnover markers may be at increased risk of SF. Female runners need routine screening for risks associated with SF occurrence. As bone mineral density and bone turnover markers are not routinely assessed in this population, important risk factors may be missed.

A cross-sectional study of the effects of load carriage on running characteristics and tibial mechanical stress: implications for stress-fracture injuries in women

BackgroundLoad carriage is associated with musculoskeletal injuries, such as stress fractures, during military basic combat training. By investigating the influence of load carriage during exercises on the kinematics and kinetics of the body and on the biomechanical responses of bones, such as the tibia, we can quantify the role of load carriage on bone health.MethodsWe conducted a cross-sectional study using an integrated musculoskeletal-finite-element model to analyze how the amount of load carriage in women affected the kinematics and kinetics of the body, as well as the tibial mechanical stress during running. We also compared the biomechanics of walking (studied previously) and running under various load-carriage conditions.ResultsWe observed substantial changes in both hip kinematics and kinetics during running when subjects carried a load. Relative to those observed during running without load, the joint reaction forces at the hip increased by an average of 49.1% body weight when subjects carried a load that was 30% of their body weight (ankle, 4.8%; knee, 20.6%). These results indicate that the hip extensor muscles in women are the main power generators when running with load carriage. When comparing running with walking, finite element analysis revealed that the peak tibial stress during running (tension, 90.6 MPa; compression, 136.2 MPa) was more than three times as great as that during walking (tension, 24.1 MPa; compression, 40.3 MPa), whereas the cumulative stress within one stride did not differ substantially between running (15.2 MPa · s) and walking (13.6 MPa · s).ConclusionsOur findings highlight the critical role of hip extensor muscles and their potential injury in women when running with load carriage. More importantly, our results underscore the need to incorporate the cumulative effect of mechanical stress when evaluating injury risk under various exercise conditions. The results from our study help to elucidate the mechanisms of stress fracture in women.

Vitamin D and stress fracture: the contribution of vitamin D receptor gene polymorphisms

Vitamin D is essential for optimal bone health. Stress fracture is an overuse injury often occurring in active populations. Study results indicate an association exists between vitamin D status and the risk of stress fracture, and one intervention trial demonstrated a reduction in stress fractures in women consuming supplemental vitamin D and calcium. A recent study found that two polymorphisms in the vitamin D receptor (VDR), Fok1 and Bsm1, may increase the risk of stress fracture. Although further study is required, screening for VDR polymorphisms may become a tool for identifying individuals at increased risk of stress fracture during physical training.

FEMALE TRACK ATHLETES ARE AT INCREASED RISK FOR STRESS FRACTURES

A number of studies support a greater risk for sustaining a stress fracture in women. This finding is especially noted in military studies, but has not been a consistent finding in the athletic population. There are currently no prospective studies in athletes that have demonstrated a gender difference in stress fracture incidence. OBJECTIVES: To assess if female collegiate track and cross-country athletes are at higher risk for stress fractures compared to male athletes in a five year prospective study. METHODS: Athletes on the UCLA track and cross country teams were followed prospectively from the fall of 1996 through the spring of 2001. There were a total of 211 athletes (116 males and 95 females) participating in the study. Athletes completed a detailed medical questionnaire and had a physical examination annually. Injured athletes were initially examined by an athletic trainer and referred to the team physician. If a stress fracture was suspected after obtaining a history and physical examination, X-rays were obtained. If X-rays were negative, MRI was used for diagnosis. The incidence of stress fractures was determined for male and female athletes and regression analysis was used to assess if gender, as well as other variables, were risk factors for stress fracture. RESULTS: The incidence rate of stress fractures for female athletes was 10.7 percent of total years of participation in the study, and 5.1 percent for males athletes (p < 0.038). The incident rate ratio was 2.1, females to males. CONCLUSION: Female track and cross country athletes are at higher risk for sustaining a stress fracture compared to male athletes. Further studies are needed to explore these findings. Funding: USOC Sport Science and Technology Grant, USA Track and Field and the UCLA General Clinical Research Center.

QUANTIFICATION OF BONE BREAKDOWN MARKERS IN ARMY MEN AND WOMEN WITH STRESS FRACTURES

1632 Exercise-induced stress fractures present a serious health threat in physically active populations. A urinary marker for bone breakdown was tested in 7 male and 6 female West Point cadets who sustained a metatarsal stress fracture (fx) after a road march. This test measured deoxypyridinoline (DPD) from Type I collagen of bone. Values from these subjects were compared with 7 male and 4 female control subjects drawn from the same West Point class and matched for age, height, and weight. All subjects submitted first a.m. urine specimens 7-10 days following a 42 km road march with backpack loads of 33 kg. Urine specimens were run on the IMMULITE Immunoassay Analyzer for DPD and creatinine (creat), and DPD/creat (nM/mM) ratios were calculated. Stress fx and control groups were compared for DPD/creat ratios within gender using the t test for independent samples. Results showed no difference in DPD/creat ratios between male stress fx and control groups. However, in women, the DPD/creat ratio was significantly higher in the stress fx group than the controls (*P<0.01). TableTableThese data suggest that urinary DPD may be a marker for stress fracture in women. Serial measurement of pre-injury DPD may be warranted to determine its value in predicting stress fractures.

Risk factors for stress fractures in track and field athletes. A twelve-month prospective study.

The aim of this 12-month prospective study was to investigate risk factors for stress fractures in a cohort of 53 female and 58 male track and field athletes, aged 17 to 26 years. Total bone mineral content, regional bone density, and soft tissue composition were measured using dual-energy x-ray absorptiometry and anthropometric techniques. Menstrual characteristics, current dietary intake, and training were assessed using questionnaires. A clinical biomechanical assessment was performed by a physical therapist. The incidence of stress fractures during the study was 21.1% with most injuries located in the tibia. Of the risk factors evaluated, none was able to predict the occurrence of stress fractures in men. However, in female athletes, significant risk factors included lower bone density, a history of menstrual disturbance, less lean mass in the lower limb, a discrepancy in leg length, and a lower fat diet. Multiple logistic regression revealed that age of menarche and calf girth were the best independent predictors of stress fractures in women. This bivariate model correctly assigned 80% of the female athletes into their respective stress fracture or nonstress fracture groups. These results suggest that it may be possible to identify female athletes most at risk for this overuse bone injury.