Efficacy of semi-customized exercises in preventing low back pain in high school volleyball players: A randomized controlled trial.

BACKGROUND: Low back pain (LBP) is a common injury in high school volleyball players. We hypothesized that a prevention program could decrease the incidence of LBP in high school volleyball players. This study was an in-season cluster-randomized controlled trial. METHODS: We block-randomized 8 high school volleyball teams comprising 70 players aged 15 to 17 years into the intervention (4 teams, 34 players) and control (4 teams, 36 players) groups. The intervention program consisted of 9 physical function tests as well as 1 or 2 self-selected preventive exercises, including dynamic thoracic mobility, trunk stabilization exercises, and static stretching, performed during warm-up. Both groups were followed up for 4 weeks, during which the incidence of LBP was recorded. Physical function tests (back endurance; spinal and back flexibility; active or passive shoulder and trunk range of motion; ankle joint mobility; and iliopsoas, quadriceps, and hamstrings flexibility) were conducted before and after the intervention. RESULTS: The intervention group had a significantly lower incidence of LBP (8.8%) than the control group (33.3%) (relative risk, 3.78; 95% confidence interval, 1.17-12.23; P = .017, 1 - ß = 0.99). Lumbar extension accounted for nearly 70% of LBP incidences. Most players in the intervention group demonstrated improved physical function associated with the exercises. CONCLUSION: The semi-customized prevention program decreased the incidence of LBP and enhanced the physical function parameter in high school volleyball players.