A common case study involves a client complaining of a shoulder or knee joint problem, which is restricting the persons" movement and causing a considerable degree of discomfort and pain.
Define the movements, which occur at the joint.
The knee joint is the largest and most complex joint in the body. It allows extension, flexion and some rotation.
During knee extension, the wheel-shape femoral condyles travel like ball bearings across the flat condyles of the tibia until tension in the anterior cruciate ligament restricts further movement. This forward movement has two components that occur simultaneously. It begins with the femur sliding posteriorly on the posterior aspect of its condyles. Then as the femur begins to erect, its condyles roll forward, bringing them into full contact with the menisci. Finally because the lateral femoral condyle stops rolling before the medial condyle stops, the femur rotates medially on the tibia, which effectively "locks" the joint into a rigid structure that can support our body weight.
When the joint is fully extended, all major ligaments of the knee are twisted and taut and the menisci are compressed. For flexion to occur, the ligaments must be untwisted and become slack. This is accomplished by the popliteus muscle, which rotates the femur laterally on the tibia. .
When the knee is flexed at a right angle, considerable movement is possible - medial and lateral rotation and passive movement of the tibia forward and backward on the femur - because the collateral ligaments are slack in this position. Flexion ends the thigh and leg makes contact. .
Name the various muscles involved in those movements.
The quadriceps arises from four separate heads that form the flesh of front and sides of thighs. These heads rectus femoris, vastus lateralis, vastus medialis, vastus intermedius have a common insertion tendon, the quadriceps tendon, which inserts into the patella via the patella tendon into tibial tuberosity.