Aerobic metabolism response in paraspinal muscles of chronic low back pain patients and judo athletes during an isokinetic trunk extension exercise.

OBJECTIVE: Low back pain is a pathology associated to a trunk extensors muscles weakness. Studies suggested that it could be associated with an inadequacy between oxygen demand and oxygen utilization by paraspinal muscles (Kell and Bhambhani, 2006). In contrast to chronic low back pain (CLBP) patients, judo athletes are characterized by a great trunk extensors muscles endurance, due to their intensive solicitation within sport practice. Our purpose was to compare aerobic metabolism in those muscles of CLBP patients with judo athletes.

PATIENTS AND METHODS: Ten judokas and 11 CLBP completed a submaximal isokinetic trunk extension exercise at 60°/s (70% of the maximal total work performed in Continuous Passive Motion mode during one repetition) during 5min. The flexion at 30°/s was passive. Oxygenation and muscular blood volume (BVm) were evaluated by using near infrared spectroscopy. Oxygen consumption (VO2) was measured by using metabolic gaz analyser. Total work performed during exercise (TT) was measured by the dynamometer.

RESULTS: TT and VO2 were lower in CLBP (P<0.05), whereas the ratio VO2/TT was greater in CLBP (P<0.05). BVm decreased significantly only for CLBP during exercise (P<0.05). Muscular desoxygenation increased significantly only for the judokas group (P<0.05).

DISCUSSION/CONCLUSION: This study brings out the weakness of paraspinal muscle in CLPB, and the diminution of the motor efficiency during a submaximal exercise, compared to judo athletes. Our results suggest that it is associated to a diminution of BVm and a lower O2 extraction in paraspinal muscles. It could suggest a diminution of the paraspinal muscles aerobic fitness in CLBP patient.