Activation of paraspinal and abdominal muscles during manually assisted and nonassisted therapeutic exercise

dObjective: To assess the activities of the paraspinal and abdominal muscles during manually assisted therapeutic exercises (MATEs) and nonassisted therapeutic exercises (NATEs) that are used in the initial phases of the progressive exercise programs designed for the treatment of low back pain. Design: Thirteen healthy subjects volunteered in the study. Surface electromyography (EMG) was recorded. The recorded EMG signal was averaged and normalized to the maximal EMG amplitude obtained during the maximal voluntary contraction (%EMG(max)). Results: In general, the %EMG(max) values were higher during NATEs than during MATEs. Sitting seemed to activate lumbar L5 level paraspinal muscles to the same extent as MATEs. Conclusion: MATEs require only minimal trunk muscle activities, and thus, they may not be sufficiently intense to improve the trunk muscle performance. NATEs require high trunk muscle activities that are adequate for improving the trunk muscle performance, but they may cause high compressive loading of the lumbar spine, and if unchecked, this can aggravate low back pain.