Aim
The aim of the BAILS study was to investigate the relationship of bone health and other risk factors to the incidence of lumbar bone stress injury (LBSI) in youth community cricket bowlers.
Methods
A prospective, observational study of young cricket bowlers was conducted during the 2023/24 cricket season in southeast Queensland. Measures included: anthropometrics, previous LBSI/bone stress injury, bowler type (fast, spin, slow), pre-season bowling workloads; sleep behaviours (adolescent sleep hygiene scale); calcium intake (AusCal questionnaire); prior physical activity (BPAQ); BMD from ultrasound (QUS, REMS), back extensor strength, hip and pelvic stability (star excursion balance test), maximum bowling speed (Stalker II radar gun), and seasonal bowling workloads (logbook). Symptomatic bowlers were assessed by a Sports Physician and referred for MRI.
Results
102 community cricket bowlers (M=78, F=24) of mixed ability participated in pre-season testing and were monitored for LBSI. Sixteen participants had a previous LBSI (M=13, F=3). During season 2023/24 there were 16 new LBSIs (15.7%), 13 male (17%), and 3 female (12.5%), and 5 recurrent injuries (42%). Compared with the uninjured bowlers, injured bowlers were 1.3 years further past peak height velocity (yPHV) (95% CI 0.1-2.4), 10.5 cm taller (95% CI 1.3-14.5); 10.1 kg heavier (95% CI 0.7-19.0); bowled 10.6 km/hr faster (95% CI 1.7-19.5); had 0.024 g/cm2 higher lumbar spine BMD (95% CI 0.003-0.052), 0.069 g/cm2 higher femoral neck BMD (95% CI 0.033-0.113), and 8.2 Db/MHz higher front foot calcaneal BUA (95% CI 0.5-15.9). Consistent trends for acutely increased workload 4-5 weeks prior to increased LBSI incidence were observed.
Conclusions
Despite higher spine and hip BMD, teenage fast bowlers in the years immediately post puberty, who are taller and heavier than average are most likely to develop an LBSI, particularly with high sudden changes in workload.