Articular capsule

An articular capsule (or joint capsule) is an envelope surrounding a synovial joint.

Layers
Each capsule consists of two layers:
 * an outer layer (stratum fibrosum) composed of white fibrous tissue
 * an inner layer (stratum synoviale) which is a secreting layer, and is usually described separately as the synovial membrane.

Diseases
Frozen shoulder (adhesive capsulitis) is a disorder in which the shoulder capsule becomes inflamed and stiff.