Joints Joints are the areas where two bones meet. They can be classified into three groups: 1)  Immovable (fibrous) e.g. skull bones (sutures), pelvis & sacrum 2) Slightly movable (cartilaginous) e.g. vertebrae of spine & where the ribs join the sternum 3) Freely movable (synovial) e.g. limb joints, elbow, knee, ankle, hip, shoulder

Structure of Synovial Joints They have bones covered at their end surfaces with articular cartilage. The fluid filled synovial cavity is surrounded by the synovial membrane, which secretes synovial fluid for lubrication, aiding in movement. Ligaments cross over joints and connect bone to bone. Whilst tendons join muscles to bone.

Movements of Synovial Joints Flexion is to bend at a joint, or to reduce the angle. Extension is to straighten at a joint, or to increase the angle, for example, from 90 degrees to 180 degrees. Abduction is movement away from the midline, or to abduct. Adduction is movement toward the midline, or to add.

Movements of Synovial Joints Supination is to rotate the forearm so that the palm faces forward. Pronation is to rotate the forearm so that the palm faces backward. Medial Rotation is to turn inward. Lateral Rotation is to turn outward.

Movements of Synovial Joints Dorsiflexion is moving your foot toward your knee, eg. Standing on your heels. Plantar flexion is standing on tip toes by extending the ankle. Inversion is where the sole of the foot is turned inward. Eversion is where the sole of the foot is turned outward. Dorsiflexion Plantar Flexion

Movements of Synovial Joints Elevation Elevation is the raising or moving a part superiorly (lifting the shoulders) Depression is the lowering or moving a part inferiorly (dropping the shoulders) Circumduction is a circular movement that combines flexion/extension with abduction/adduction (circling the leg in the hip socket) Depression Circumduction