Fig. 5From: Degenerative characteristics of multifidus at different vertebral levels of scoliosis in patients with degenerative lumbar scoliosis and relationship of these degenerative characteristics with surface electromyography activityTypical processed images of three sets of motion signals acquired by the IMU: acceleration along the vertical axis (x-axis), horizontal axis (y-axis), and anteroposterior axis (z-axis). a Standing still phase. b Maximal standing flexion/extension maintenance phase. The X-axis is the data acquisition frequency (Hz), and the Y-axis is the acceleration of motion (mg)Back to article page