Comparison of Trunk Muscle Endurance between Lumbar Rotation with Flexion Syndrome and Rotation with Extension Syndrome

Comparison of Trunk Muscle Endurance between Lumbar Rotation with Flexion Syndrome and Rotation with Extension Syndrome

Background Movement system impairment (MSI) is designated through elicited or increased symptoms in the specific direction of alignment, extremities, or spinal movement. According to the classification of MSI in non-specific chronic back pain (NCLBP), rotation with extension (RE) syndrome is the most common cause of symptoms, while rotation with flexion (RF) syndrome reveals flexible motion and decreased symptoms in the opposite direction of the RE subgroup. Purpose The purpose of the present study was to compare trunk endurance tests between subgroups based on movement system impairment (MSI). Study design Cross-over design. Methods Two subgroups according to the classification of MSI in 30 patients with NCLBP were compared in three trunk endurance tests: flexor, lateral flexor and extensor endurance. Results The rotation with extension (RE) group had a longer mean hold time during the extensor endurance test relative to the flexor endurance test (p<0.01), while the rotation with flexion (RF) group performed significantly better in the flexor endurance test than they performed in the extensor endurance test (p<0.01). The ratio of endurance times between the flexor and extensor endurance tests was also statistically significant between the two groups (p<0.001). Conclusions The maintenance times of trunk muscle endurance in a specific- direction was related to the subgroups by MSI classification, and it could provide information regarding the assessment and program trunk endurance of a specific-direction in the homogeneous group.