If an athlete had decreased strength in the quadriceps muscle due to anterior cruciate ligament repair,which of the following problems may be present during the stance phase of gait?
A) Inability to flex the knee (concentric action)
B) Inability to control flexion of the knee (eccentric action)
C) Inability to extend the knee (concentric action)
D) Inability to control extension of the knee (eccentric action)

Question

Quizplus · Accepted Answer

During the stance phase of gait, the body weight is supported on the stance leg and the quadriceps muscle is responsible for controlling flexion of the knee. If there is decreased strength in the quadriceps muscle, the athlete may have difficulty controlling flexion of the knee, which is an eccentric action. The other options, inability to flex the knee (concentric action) and inability to extend the knee (concentric action), are less likely to be problems during the stance phase of gait. The option of inability to control extension of the knee (eccentric action) is also less likely because the hamstring muscles are responsible for controlling knee extension during the swing phase of gait, not the quadriceps muscles during the stance phase.

If an Athlete Had Decreased Strength in the Quadriceps Muscle