Skeletal muscles are striated muscular tissue that can contract and lengthen to produce stabilization and movement.    Muscles work together to produce the desired movement.  Muscular imbalances can occur due to improper training or lack of use.  The imbalances does not necessarily occur at a specific joint but can occur either above or below the joint.  When there is a muscle  imbalance, they can cause an increase in tension and torque which can ultimately lead to injury.  In the musculoskeletal section, the concentration is on some of the injuries at the knee that can occur due to muscle imbalances.

Hip Muscle Imbalance

Patella Dislocation
Patellofemoral Pain Syndrome