Monitoring iliopsoas muscle contraction in idiopathic lumbar scoliosis patients

Background: Curve evolution in idiopathic scoliosis frequently occurs in lumbar and thoracic-lumbar spine. The spinal and iliopsoas muscles play a major role in maintaining the static and dynamic stability of the spine. Objective. To monitor by video recording, the degree to which asymmetric isometric contractions of the iliopsoas muscle improve the lumbar curve.

Design: 10 subjects (9 female, 1 male), mean age of 14.1 years (11-18), who were undergoing rehabilitation for idiopathic scoliosis. 8 subjects wore a brace, 6 had a single lumbar curve, 4 had a thoracic curve; 9 curves were convex to the left and 1 convex to the right. The mean Cobb angle was 20.1° ((±8.2523) with a mean degree of rotation of 1.2 ((±0.4216).

Method: The scoliotic curves were monitored on video whilst the patients performed muscle contraction exercises. Adhesive markers were applied to the skin to be used as reference points of the curve on video. Subjects performed the exercises in a sitting position, facing away from the video camera, with their knees bent at an angle of 90°. The complete exercise procedure was as follows: initial lengthening of the spine and postural control, concentric activation of the iliopsoas, isometric activation for about 3 seconds, then final release. Differences in curvature angle detected on the video recording were analysed and processed using the computer software Dartfish Pro Suite 5.0-Dartfish LTD-Switzerland.

Results: The mean angle of correction through exercise was 6.9° ((±3.6) during concentric activation and 4.9° (±3.5) during isometric activation of the iliopsoas. Conclusions. Data show the corrective effect that iliopsoas muscle contraction produces on the scoliotic curve.