Predictors of stress fracture susceptibility in young female recruits

Stress fracture risk factors in female football players and their clinical implications

A stress fracture represents the inability of the skeleton to withstand repetitive bouts of mechanical loading, which results in structural fatigue, and resultant signs and symptoms of localised pain and tenderness. Reports of stress fractures in female football players are not prevalent; however, they are probably under-reported and their importance lies in the morbidity that they cause in terms of time lost from participation. By considering risk factors for stress fractures in female football players it may be possible to reduce the impact of these troublesome injuries. Risk factors for stress fractures in female football players include intrinsic risk factors such as gender, endocrine, nutritional, physical fitness and neuromusculoskeletal factors, as well as extrinsic risk factors such as training programme, equipment and environmental factors. This paper discusses these risk factors and their implications in terms of developing prevention and management strategies for stress fractures in female football players.

Factors That Affect the Young Female Athlete

The past 35 years have seen a tremendous increase in the number of female athletes at all ages and abilities. Recent research has shown a myriad of benefits for girls and women who participate in sports. Physical activity positively influences almost every aspect of a young woman's health, from her physiology to her social interactions and mental health. As the level of girls' participation in sports increases, it is important to examine their risk factors for sports-related injuries.

Medial tibial stress syndrome in high school cross-country runners: incidence and risk factors

STUDY DESIGN

Prospective cohort.

OBJECTIVE

To determine (1) the cumulative seasonal incidence and overall injury rate of medial tibial stress syndrome (MTSS) and (2) risk factors for MTSS with a primary focus on the relationship between navicular drop values and MTSS in high school cross-country runners.

BACKGROUND

MTSS is a common injury among runners. However, few studies have reported the injury rate and risk factors for MTSS among adolescent runners.

METHODS AND MEASURES

Data collected included measurement of bilateral navicular drop and foot length, and a baseline questionnaire regarding the runner's height, body mass, previous running injury, running experience, and orthotic or tape use. Runners were followed during the season to determine athletic exposures (AEs) and occurrence of MTSS.

RESULTS

The overall injury rate for MTSS was 2.8/1000 AEs. Although not statistically different, girls had a higher rate (4.3/1000 AEs) than boys (1.7/1000 AEs) (P = .11). Logistic regression modeling indicated that only gender and body mass index (BMI) were significantly associated with the occurrence of MTSS. However, when controlled for orthotic use, only BMI was associated with risk of MTSS. No significant associations were found between MTSS and navicular drop or foot length.

CONCLUSIONS

Our findings suggest that navicular drop may not be an appropriate measure to identify runners who may develop MTSS during a cross-country season; thus, additional studies are needed to identify appropriate preseason screening tools.

Epidemiology of Stress Fracture and Lower-Extremity Overuse Injury in Female Recruits

PURPOSE

The purpose of this prospective study was to examine rates and risk factors for overuse injuries among 824 women during Marine Corps Recruit Depot basic training at Parris Island, SC, in 1999.

METHODS

Data collected included training day exposures (TDE), baseline performance on a standardized 1.5-mile timed run, and a pretraining questionnaire highlighting exercise and health habits. The women were followed during training for occurrence of stress fracture and other lower-extremity overuse injury.

RESULTS

There were 868 lower-extremity overuse injuries for an overall injury rate of 12.6/1000 TDE. Rates for initial and subsequent injury were 8.7/1000 and 20.7/1000 TDE, respectively. There were 66 confirmed lower-extremity stress fractures among 56 (6.8%) women (1.0/1000 TDE). Logistic regression modeling indicated that low aerobic fitness (a slower time on the timed run (> 14.4 min)), no menses in six or more consecutive months during the past year, and less than 7 months of lower-extremity weight training were significantly associated with stress fracture incidence. Self-rated fair-poor fitness at baseline was the only variable significantly associated with other non-stress fracture overuse injury during basic training.

CONCLUSIONS

Among this sample of women, the risk of lower-extremity overuse injury was high, with a twofold risk of subsequent injury. The results suggest that stress fracture injury might be decreased if women entered training with high aerobic fitness and participated frequently in lower-extremity strength training. Furthermore, women reporting a history of menstrual irregularity at their initial medical exam may require closer observation during basic training.