The Association between Increased Body Mass Index and Overuse Injuries in Israel Defense Forces Conscripts

Objectives: To examine the association between body mass index (BMI) and overuse injuries (OI) among Israel Defense Forces soldiers, in different corps. Methods: Conscripts between 2003 and 2012, infantry, armored corps and intelligence corps (controls) were studied. OI data were taken from computerized patient records. The BMI was classified as underweight, low-normal (18.5-21.9), high-normal (22-24.9), overweight and obese. Multivariate analysis was performed using logistic regression. Results: There were 73,640 soldiers: 42,506 infantry, 20,781 armor and 10,353 intelligence. OI rates were 52.2, 51.6 and 27%, respectively. OI rate was directly proportional to BMI in all groups (relative risk compared to low-normal, underweight: 0.97, high-normal: 1.05, overweight: 1.11, obese: 1.19, p < 0.05 for all), increased height and younger age. By logistic regression, OI were significantly associated with training group, higher BMI, increased height, younger age, lower education, lower socioeconomic status and lower psychotechnical grading. Throughout the BMI range, each additional unit of BMI was associated with a 2% OI increase. Conclusions: Higher BMI was associated with a higher rate of OI in all groups. Therefore there is no point in differentially assigning recruits based on BMI.