Isokinetic trunk muscle strength in braced vs non-braced adolescents with lumbar spondylolysis: A retrospective study

Lumbar spondylolysis is a common cause of lower back pain in adolescents and is often managed conservatively with trunk bracing. However, the effects of trunk bracing on trunk muscle strength remain unclear. This study aimed to compare isokinetic trunk muscle strength between patients with lumbar spondylolysis who wore a brace and those who did not during rehabilitation.

A retrospective observational study was conducted on 20 adolescents diagnosed with lumbar spondylolysis. Participants were classified into a brace-wearing group (n = 10) and a non-brace-wearing group (n = 10). Isokinetic trunk muscle strength was assessed using the Biodex System 3 at angular velocities of 60°/sec, 120°/sec, and 180°/sec. Outcome measures included PEAK TORQUE, PEAK TORQUE/BODY WEIGHT, ANGLE OF PEAK TORQUE, MAX REP TO TOTAL WORK, and TOTAL WORK. Group comparisons were performed using independent t-tests or Mann-Whitney U tests.

Significant differences were found in trunk flexor strength at 60°/sec, with the brace-wearing group demonstrating lower values in MAX REP TO TOTAL WORK (P = 0.04) and TOTAL WORK (P = 0.02). No significant differences were observed in trunk extensor strength between groups.

Brace-wearing as a component of rehabilitation for lumbar spondylolysis may lead to reduced trunk flexor strength, emphasizing the need for targeted strength training at multiple trunk angles. These findings add to the understanding of the impact of bracing on trunk muscle function and highlight the importance of personalized rehabilitation strategies. Future research should focus on longitudinal studies to further clarify these effects and optimize treatment protocols.