The nurse is caring for a client with a knee injury. The nurse would correctly identify the knee as which of the following joint types?

Question

1. Saddle
2. Hinge
3. Pivot
4. Plane

Answer 1

2
Rationale 1: Saddle joints consist of an articulating bone having both concave and convex areas (resembling a saddle). The opposing surfaces fit together. The carpometacarpal joints of the thumbs are an example.
Rationale 2: In hinge joints, a convex projection of one bone fits into a concave depression in another. Motion is similar to that of a mechanical hinge. These joints permit flexion and extension only. Examples include the elbow and knee joints.
Rationale 3: In pivot joints, the rounded end of one bone protrudes into a ring of bone (and possibly ligaments). The only movement allowed is rotation of the bone around its own long axis or against the other bone. An example is the joint between the atlas and axis of the neck.
Rationale 4: In plane joints, the articular surfaces are flat, allowing only slipping or gliding movements. Examples include the intercarpal and intertarsal joints, and the joints between the articular processes of the ribs.