OVERVIEW
The latissimus dorsi is the large, flat muscle that gives the back its “V” shape. Its tendon fixes onto a groove at the top of the upper-arm bone and helps pull the arm down, back, and inwards. A rupture is a tear of this muscle or its tendon. Although rare, it can cause sudden pain in the back of the shoulder or armpit, especially in sports that involve powerful overhead pulling or throwing. Most people recover well with rest and physiotherapy; surgery is usually reserved for elite or professional athletes with complete tears.
CAUSES
• Eccentric overload during the follow-through of a throw (baseball, cricket, javelin).
• Heavy pulling while the arm is above shoulder level (water-skiing, rock climbing, CrossFit).
• Sudden slips or falls where the arm is yanked upwards.
SYMPTOMS
• Sharp pain and a possible “pop” at the back of the armpit.
• Bruising or swelling down the side of the chest or upper arm.
• Weakness when pulling, rowing, or doing a pull-up.
• A hollow where the back fold of the armpit used to be.
• Full arm movement may still be possible, which can mask the injury.
DIAGNOSIS
A sports or shoulder specialist will take a detailed history and examine the shoulder for tenderness, bruising, and strength loss. X-rays usually look normal but rule out bone injury. An MRI scan confirms the tear, shows its size, and checks whether the tendon has pulled back from the bone. An extended scan of the side of the chest may be needed because routine shoulder MRI can miss the full muscle.
TREATMENT OPTIONS
Non-surgical care (recommended for most patients)
• Short period of rest, ice, and pain relief medicine such as paracetamol or ibuprofen as advised.
• Early gentle movement to prevent stiffness.
• Structured physiotherapy to restore shoulder movement, build rotator-cuff and shoulder-blade strength, and gradually return to sport.
• Typical return to recreational sport and gym work in three to four months once pain-free strength has returned.
Surgical repair (only for complete tears in high-level athletes)
• The torn tendon is re-attached to the arm bone with strong sutures and anchors or buttons.
• Best performed within a few weeks to avoid scarring and retraction.
• Hospital stay is usually overnight; arm is supported in a sling for comfort.
• Physiotherapy starts immediately with assisted movements, followed by progressive strengthening.
• Full training and throwing generally resume six months after surgery, once strength matches the opposite side.
REHABILITATION TIMELINE AFTER SURGERY
Weeks 0 – 6: Sling for comfort, assisted arm movements below shoulder height.
Weeks 6 – 12: Light resistance-band work, gradual increase in range.
Weeks 12 – 24: Gym programme, power drills, and sports-specific skills.
6 months+: Return to full sport once cleared by the surgical team.
OUTLOOK
• Non-operative treatment restores everyday function for most people and often allows return to non-professional sport.
• Surgical repair in committed athletes shows over 90 % return to the same performance level within six to eight months.
• Minor changes in muscle shape may remain but rarely affect strength in routine activities.
FREQUENTLY ASKED QUESTIONS
Is the tear dangerous?
No. It is painful and limits strength but does not threaten life or limb.
Will bruising always appear?
Bruising is common but not universal. Some tears show very little discoloration.
Can driving continue?
Driving is safe once pain is controlled and arm strength allows full control of the steering wheel, usually within two weeks without surgery and four to six weeks after surgery.
Will a sling be needed if surgery is not done?
A sling may aid comfort for the first few days only. Early, gentle movement is encouraged.
What happens if the dip at the back of the armpit stays?
A slight cosmetic hollow may persist after a non-surgical recovery, but arm power and function are usually normal.
Call to Action
If you have pain, book an appointment to be reviewed by Prof Imam or another member of our specialist team at The Arm Clinic. Early specialist care helps prevent long-term issues. Visit www.TheArmDoc.co.uk or book your consultation today. Phone: 020 3384 5588 | Email: Info@TheArmDoc.co.uk
Disclaimer
This information is for general educational purposes and should not be used as a substitute for professional medical advice. Consult a healthcare professional for individual guidance on your condition and treatment options.
This page was last clinically updated in May 2025