Figure 1. FEDS System for Classifying Glenohumeral Joint Instability.
The FEDS acronym stands for Frequency, Etiology, Direction, and Severity. Each component of the FEDS system is subclassified into different descriptors. The descriptors are italicized and defined. One descriptor from each component would be used to describe an individual patient. For example: Solitary, Traumatic, Anterior, Dislocation would be one type of instability.