Oral Presentation 33rd ASM of the Australian & New Zealand Bone & Mineral Society 2023

Preventing Bone and Muscle Injury and Reducing Costs in Australian Army Recruit Training with Bone-Targeted Pre-Conditioning: The PREFIT Study (#42)

Belinda Beck 1 2 3 , Graeme Jones 4 , Stephan Rudzki 5 , Mark Barclay 6 , Paul Scuffham 1 3
  1. Griffith University, QLD, Australia
  2. The Bone Clinic, Brisbane, QLD, Australia
  3. Menzies Health Institute Queensland, Gold Coast
  4. University of Tasmania, Hobart
  5. MO4 Regional Health Service, SNSW, Canberra
  6. Kapooka Health Centre, Wagga Wagga

Purpose

Bone adapts to mechanical loading but overly rapid loading increments, as during Army recruit training (ART), cause bone stress injuries. We aimed to 1. determine whether bone-targeted preconditioning could reduce musculoskeletal injuries and costs during ART (Australian Army Recruit Training Centre, Kapooka, NSW), and 2. identify factors associated with musculoskeletal injury during ART.

Methods

PREFIT was a controlled proof-of-concept trial offering 45mins 5d/wk bone-targeted preconditioning to candidates to the Australian Army enlisting within 5 months. We collected biometrics, health history, medications, heel BUA (QUS, Achilles, GE); muscle strength (TTM Muscle Meter), muscle power (GymAware); functional reach; #push-ups, #sit-ups, shuttle run performance, vitamin D; prior physical activity (BPAQ); calcium (AusCal) and prior injuries. Preconditioning adherence and injuries during 12-week ART were monitored. Rates and costs of injury in recruits who did and did not undertake pre-conditioning and predictors of injury were examined.

Results

We enrolled 91 candidates into PREFIT training of whom 37 entered ART (54 decided not to enlist). 25 completed sufficient PREFIT training to qualify as ‘pre-trained’. 349 platoon-mates consented to be controls (overall mean age, 22±5.4yrs). 19% of the PREFIT-group sustained an injury versus 61.2% of non-PREFIT trained recruits. 10.7% of the PREFIT group sustained a musculoskeletal injury versus 37.7 % of the non-PREFIT group. There was insufficient power to compare bone injuries, but for every 1-unit increase in BUA or #push-ups, the odds of bone injury was 0.97 and 0.96 times lower, respectively (p=0.033;p=0.041). Lower extremity injury and bone injury were negatively associated with height, BUA, leg power, #push-ups, #sit-ups and shuttle run, and positively associated with smoking, and previous medication. Medical costs were $1,308 for non-PREFIT versus $2,241 for PREFIT recruits.

Conclusions

A bone-targeted preconditioning program reduced musculoskeletal injury and costs to the Army for recruit training. Taller, stronger, fitter recruits are less at risk.