It is the largest & strongest cuff muscle, providing 53% of total cuff strength. The upper 60% of the insertion is tendinous and the lower 40% muscle. It is a passive restraint in neutral, but not abduction.
It's role is to turn the arm inwards and is a key muscle in doing any lifting movements across your chest or twisting inwards. It is essential for overhead sports, such as swimming, racquet sports and throwing.
Low demand and elderly patients can be well managed with physiotherapy rehabilitation.
In an active person, surgical repair is recommended. The surgery can be performed by arthroscopy or open surgery depending on the surgeon's expertise, tear pattern and patient. If the biceps is affected a biceps tenodesis is generally required also.
Some tears may be too old (chronic) and large for a direct repair. In these cases a Pec Major transfer operation can be performed.