The latissimus dorsi is the broadest muscle of the back. It extends from the top of the hip to the lower six thoracic vertebrae in the mid-back and up to the top of the humerus -- the bone in the upper arm that forms the ball of the ball-and-socket shoulder joint -- at the front of the shoulder.
Like all muscle strains, the lat strain is broken down into three grades. Grade 1 is a mild strain, Grade 2 is a moderate strain and Grade 3 is a severe strain in which the muscle ruptures.
Typical recovery time
Recovery time varies depending on the strain, with Grade 1 strains typically requiring 2-3 weeks and Grade 2 strains usually taking at least a month. Grade 3 strains often require surgery, however, and can come with considerably longer recovery periods.