We examine the postural profile and muscular forces of the trunk and inferior members of patients with chronic low back pain.

In this study, we include 60 subjects forming two groups: a first group (G1) of 30 patients with chronic low back pain and a second group (G2) of 30 healthy subjects. Every subject profited from an isokinetic evaluation of the muscular forces of the trunk (at 60 and 90°.s⁻¹) and knees (at 60 and 120°.s⁻¹) and of a postural evaluation. The isokinetic evaluation was carried out using Cybex^® Norm II dynamometer with its Trunk Extension/Flexion (TEF) module set in concentric mode. The parameter under study was the torque peak. The postural evaluation was accomplished using the platform SATEL for the balance analysis associated with four conditions: static on stable plan open eyes (OE) then closed eyes (CE) and static on unstable plan OE then CE. The parameters under study were the averages of the total lengths, total surfaces, and the X and Y means.

The averages of the torque peaks of the trunk flexor and extensor muscles at the speeds of 60 and 90°.s⁻¹ were inferior in group G1 as compared to G2. The differences were statistically insignificant only for the extensor muscles (p<0.005). The averages of the torque peaks of the knee flexors and extensors at 60 and 120°.s⁻¹ were the lowest in group G1. The differences were significant (p<0.05). The averages of postural parameters were more important in group G1, indicating a postural deficit in this group.

We showed deficits of the posture and muscles of the trunk and knees of patients with chronic lumbar pain. The muscular deficit of the trunk predominates on extensors.