Figure 10

Synergist substitution can be identified and prevented during the MMT. With a weak gluteus maximus, the examiner can visualize a lifting of the pelvis with external rotation and abduction of the hip, with recruitment of the ipsilateral hamstring, thoracolumbar extensors, and contralateral leg flexor muscles. The pelvis externally rotates because the weak gluteus maximus recruits synergists to facilitate its action during the MMT.