Which of the Following Is Not True Regarding Strength and Endurance

Which of the following is not true regarding strength and endurance being essential for maintenance of patellofemoral stability?

A) Functional weight bearing activities such as step-ups or squats are particularly useful for strengthening and endurance.
B) Patellofemoral stability may be developed by resisted knee extension activities from a seated position.
C) Quads are particularly prone to atrophy when injuries occur.
D) Strength and flexibility are not often a problem with the muscles of the knee joint.