The function of the Latissimus Dorsi muscle is to:
- internally (medially) rotate the shoulder
- extend the arm behind you
- adduct the arm toward the body.
I jokingly like to call it the handcuff muscle. If you do all the actions, it will place your arms behind your back, as if you were being handcuffed.
The Lats also assist in doing the following functions:
- extension and flexion the trunk
- lateral flexion of the trunk (side bend)
- anterior and pelvic tilt
- depression of the scapula
- protraction of the scapula
- inhalation and exhalation movements of the ribcage
Once you are no longer in the acute stage, gentle stretches are encouraged to regain range of motion of the Latissimus Dorsi. Your doctor or physical therapist can also recommend some strengthening exercises that you can do at home to help prevent further injuries of your Lats. In most cases, Latissimus Dorsi pain will go away on its own with rest, massage, stretching, and exercises that can be done at home.