Chapter 10, Problem 1CCS

45-Year-Old Female with Motor Nerve Damage

In Chapters 7 and 8, you met Kayla Tanner, who suffered a dislocated right hip in a car accident. Six weeks later, Mrs. Tanner was still unable to walk or run without hip pain, and had weakness in flexion at the knee, excessive foot inversion and plantar flexion, and significant “foot drop” (the inability to dorsiflex the foot).

Electromyography (measurement of muscle electrical activity) and nerve conduction studies (measurement of the speed of nerve impulses) revealed sciatic nerve damage, most likely a result of the nerve being compressed when the hip was dislocated. This large nerve innervates many lower limb muscles. Since her surgery, Mrs. Tanner has been undergoing intense physical therapy and has shown significant improvement.

1. During her initial visit, the physical therapist focused on the prime movers and synergists of the hip, knee, and ankle. What are "prime movers" and "synergists”?