This study will quantify the muscle function after breast reconstruction using a minimally invasive latissimus dorsi flap. The proposed measures (clinical, isokinetic, electrophysiology, function and quality of life questionnaires) allow a precise, multidisciplinary, objective evaluation of the capacity of the latissimus dorsi muscle before surgery, 3 months, 6 months and 12 months after surgery. A function deficit is expected (decreased moment of adduction and internal rotation) 3 months after surgery and a return to the preoperative state 6 months and 12 months after surgery.