Erector Spinae and Quadratus Lumborum Muscle Endurance Tests and Supine Leg-Length Alignment Asymmetry: An Observational Study

This study suggests that, using the B-S test, the group of volunteers who demonstrated a commonly used sign of subluxation/joint dysfunction, supine LLA asymmetry, had a decreased endurance times over those who did not. The QL endurance tests showed that the QL muscle ipsilateral to the supine short leg had significantly decreased endurance times over the same-side QL fatigue times in the no leg-length asymmetry group. (J Manipulative Physiol Ther 2005;28:000-000)