Muscle strength in Brazilian firefighters with non-specific chronic low back pain: A cross-sectional study.

Background: Imbalance between flexor and extensor muscles of the trunk could negatively influence spinal stability.

Objectives: Investigate the strength balance between flexor and extensor muscles of the trunk in military firefighters with non-specific chronic low back pain (NSCLBP).

Methods: One hundred and two male firefighters were assessed in an isokinetic dynamometer at 120°/s and 60°/s to investigate the balance ratio between flexor and extensor (F/E) muscles.