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

Why This Matters

Lumbar spondylolysis is a common cause of low back pain in adolescent athletes, and bracing is frequently prescribed to promote healing. While bracing can reduce mechanical stress on the pars interarticularis, there has been concern that prolonged brace use may contribute to trunk muscle weakness during rehabilitation.

This study helps clarify that concern. The findings suggest that brace use may selectively reduce trunk flexor strength while preserving extensor strength, highlighting the importance of rehabilitation strategies that restore muscle performance before return to activity.

What the Research Found

This retrospective study compared 20 adolescents with lumbar spondylolysis, including 10 treated with a trunk brace and 10 managed without bracing during rehabilitation.

Key findings:

• Adolescents who wore a brace demonstrated weaker trunk flexor strength than those who did not wear a brace.
• The brace group generated less total work during trunk flexion testing, indicating reduced muscular endurance and strength.
• Trunk extensor strength was similar between the brace and non-brace groups.
• The authors concluded that rehabilitation following bracing should include targeted trunk flexor strengthening performed through multiple trunk angles.

Clinical interpretation:
Bracing may help protect healing structures but appears to come with a tradeoff of reduced trunk flexor strength. Rehabilitation should address this deficit before full return to sport or unrestricted activity.