Article ID: 11512
Purpose: We devised a closed kinetic chain exercise in which a person leans the trunk forward while “half sitting” (HS; sitting on the side of a seat so that only one buttock is supported) for rehabilitation after knee joint surgery. This study aimed to clarify the biomechanical characteristics during half sitting exercise (HSE) compared with squats (SQ).
Method: Ten healthy adults performed HSE and SQ. A three-dimensional motion capture system, force plate, and surface electromyography were used to measure motion and muscle activity. Then, joint angle, floor reaction force, joint moment, and electromyographic activity of the right leg were calculated.
Results: In HSE, the flexion angle and extension moment of the hip joint, the posterior component of the floor reaction force, and the muscle activity (percent maximum voluntary contraction) of the vastus medialis and semitendinosus were significantly higher than those in SQ. However, the external knee varus moment and the internal extension moment and medial component of the floor reaction force were significantly lower in HSE than in SQ.
Conclusion: HSE increases the load on the vastus medialis and semitendinosus while effectively preventing an external varus moment and an internal extension moment. These findings suggest that HSE will be useful for rehabilitation after knee surgery.
