An articular capsule (or joint capsule) is an envelope surrounding a synovial joint.
Each capsule consists of two layers:
On the inside of the capsule, articular cartilage covers the end surfaces of the bones that articulate within that joint.
The outer layer is highly innervated by the same nerves which perforate through the adjacent muscles associated with the joint.
Frozen shoulder (adhesive capsulitis) is a disorder in which the shoulder capsule becomes inflamed.
Plica Syndrome is a disorder in which the synovial plica becomes inflamed and causes abnormal biomechanics in the knee.
Left clavicle. Inferior surface.
Right hip bone. External surface.
This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.