
THE KNEE
The knee is a hinge joint that connects the thigh bone (femur) to the shin bone (tibia), allowing primarily flexion and extension with slight rotation. It also involves the patella (kneecap), which protects the joint and improves leverage for the quadriceps muscle. Key stabilizing structures include the anterior and posterior cruciate ligaments (ACL and PCL), which control forward and backward movement, and the medial and lateral collateral ligaments (MCL and LCL), which provide side-to-side stability. Two menisci (medial and lateral) act as shock absorbers and help distribute weight evenly across the joint. Muscles like the quadriceps, hamstrings, and calf muscles support movement and joint stability. The knee plays a critical role in walking, jumping, and overall lower limb function.