A PILOT STUDY TO ASSESS JOINT HYPERMOBILITY AS A PREDICTOR OF LOWER LIMB INJURY IN BRITISH OFFICER CADETS DURING THE COMMISSIONING COURSE

Abstract

Aim and objectives: The primary aim of this study was to establish whether joint hypermobility can help predict lower limb injury risk in a military population. Objectives were to (i) determine the prevalence of joint hypermobility and the level of agreement between the Beighton Scale (BS) and the Lower Limb Assessment Score (LLAS) (ii) determine the incidence and characteristics of injury during the Commissioning Course (CC) and its impact on military personnel, (iii) explore risk factors for injury in this setting including personnel demographics, physical fitness, body mass index and joint hypermobility, and (iv) explore the impact of joint hypermobility on cumulative injury and its impact. Design: Prospective, longitudinal, cohort study Setting: The 44-week CC for British Army Officers Cadets at Royal Military Academy Sandhurst. Injury data was collected at the Defence Medical Rehabilitation Centre Headley Court, using the remote Defence Medical Information Capability Programme. Participants: 169 healthy participants (156 male; mean (SD) age 23 (2) years, body mass index 24.6 (2.0) kg/m2) completed the study. Main Outcome Measures: Joint hypermobility was assessed during week 3 using the BS (0-9) and LLLAS (0-24) with higher scores indicating increased joint mobility. Secondary measures, assessed at baseline included Body Mass Index (BMI), 1.5 mile run time as a measure of aerobic fitness, smoking status and ethnicity. Results: BS scores were significantly associated with LLAS scores (p < 0.0005) and the point prevalence of joint hypermobility was 20% [95% CI 14 to 26]. One-year incidence of injury was 69.2% [95% CI 61.9 to 75.7] with 59.8% [50.8 to 68.3] attributed to overuse and the most common site of injury being the foot and ankle. Neither age, sex, BMI, smoking status, 1.5 miles run time, or hypermobility status by LLAS or BS were shown to be significant predictors of injury, number of injuries sustained or the average number of light duties. Conclusions: The BS and LLAS are highly correlated and both can effectively detect lower limb joint hypermobility. There is a high incidence of lower limb injury over the 44-week CC, with foot and ankle overuse injuries being most common. In this highly standardized population, joint hypermobility, age, body mass index, sex, ethnicity, and aerobic fitness were not significantly associated with or predictive of an increased risk of injury.