8.5: selected synovial joints

Knee joint

A synovial joint consisting of three joints within a single cavity: the femoropatellar joint and the lateral and medial tibiofemoral joints.

Tibiofemoral joint

The hinge portion of the knee; allows mostly flexion and extension with limited rotation when the knee is bent.

Femoropatellar joint

A plane joint that allows the patella to glide across the knee when the knee is flexed.

Knee ligaments

Capsular, extracapsular, and cruciate ligaments that stabilize and strengthen the knee.

Cruciate ligaments

Ligaments that keep the articulating bones of the knee aligned.

Shoulder (glenohumeral) joint

A ball-and-socket joint that is the most freely moving joint in the body but is not very stable.

Rotator cuff

Tendons that cross and encircle the shoulder joint and provide its most important stabilizing effect.

Elbow joint

A stable hinge joint between the ulna and humerus that allows flexion and extension.

Hip (coxal) joint

A ball-and-socket joint that provides a wide range of motion and is strongly stabilized by ligaments and the deep acetabular socket.

Acetabulum

The deep socket of the hip joint that contributes greatly to its stability.

Temporomandibular joint (TMJ)

The jaw joint that allows hinge-like movement and side-to-side lateral excursion.

Articular disc

A structure in the TMJ that divides the synovial cavity into compartments supporting different movements.

Lateral ligament

A ligament on the lateral side of the TMJ capsule that reinforces the joint.