Latissimus Dorsi and Teres Major Injuries

The shoulder is one of the most complex and mobile joints in the body, allowing us to reach, throw, lift, and perform countless daily activities. Much of this power and motion comes from muscles that attach deep into the upper arm. Two of these muscles—the latissimus dorsi and the teres major—play an important role in pulling, lifting, and stabilizing the arm during powerful movements. While injuries to these tendons are not as common as other shoulder problems, such as rotator cuff tears, they can cause significant pain and weakness, particularly in athletes and individuals who rely on overhead or forceful arm motions.

What are the latissimus dorsi and teres major?

The latissimus dorsi, often called the “lats,” is a large, flat muscle that covers much of the back. It extends from the lower spine and pelvis and attaches to the upper arm bone (humerus). It helps bring the arm down toward the body, rotate the arm inward, and generate powerful pulling motions.

The teres major is a smaller muscle located near the latissimus dorsi that also connects the shoulder blade to the upper arm. It works closely with the latissimus dorsi, assisting in movements such as pulling, lifting, and stabilizing the arm during rotation.

Because these two muscles function together, injuries often involve both tendons, leading to pain, weakness, and difficulty with specific shoulder motions.

What causes injuries to these muscles?

Latissimus dorsi and teres major tendon injuries typically occur during sudden, forceful movements of the arm, especially when the arm is overhead or being pulled downward with resistance. Common causes include:

• Sports-related injuries: Athletes who perform explosive overhead movements are most at risk. This includes baseball pitchers, tennis players, swimmers, and track-and-field throwers (such as javelin or discus).
• Weightlifting: Heavy lifting, particularly exercises like pull-ups, rows, or deadlifts, can overload the tendons.
• Trauma: A sudden fall, direct blow, or rapid twisting of the shoulder may also cause the tendon to tear.

Risk factors that increase the likelihood of injury include repetitive overhead training, inadequate warm-up, muscle fatigue, poor throwing mechanics, and a history of shoulder injuries.

What are the symptoms of these tendon injuries?

When the latissimus dorsi or teres major tendon is injured, symptoms can vary depending on whether the tendon is strained, partially torn, or fully torn. Common symptoms include:

• Sudden sharp pain in the back of the shoulder, upper arm, or side of the chest, often during an overhead motion such as throwing.
• Bruising and swelling around the upper arm, side of the chest, or back.
• Weakness when pulling the arm down or backward, particularly noticeable in athletes trying to throw, swim, or lift weights.
• Tenderness in the back of the shoulder or along the side of the chest wall.
• Difficulty with overhead activities, such as serving in tennis, pitching a baseball, or doing pull-ups.
• In some cases, a popping or tearing sensation may be felt at the time of injury.

Because these symptoms can overlap with other shoulder injuries, proper evaluation is essential.

How are these injuries diagnosed?

Diagnosing a latissimus dorsi or teres major tendon injury requires a thorough physical exam and, in many cases, advanced imaging.

During the exam, Dr. Waterman will ask about the onset of symptoms, the type of activity that triggered pain, and any history of prior shoulder problems. He will test strength, range of motion, and pain with specific arm movements.

Imaging studies are often used to confirm the diagnosis and assess the extent of the injury:

• Magnetic resonance imaging (MRI) provides a clear view of the tendons and surrounding structures, showing whether there is a strain, partial tear, or complete tendon rupture.
• Ultrasound may be used to evaluate the tendon in real time while the arm is moved.
• X-rays are typically normal with these injuries but may be ordered to rule out bone problems.

Early diagnosis is important because untreated tendon injuries can lead to chronic weakness, scar tissue formation, and long-term limitations in performance.

While Latissimus dorsi and teres major injuries are relatively rare, they can have a big impact on athletic performance and daily life. For professional and recreational athletes, a missed or delayed diagnosis can prolong recovery and increase the risk of re-injury. Even in non-athletes, these injuries can make it difficult to lift, pull, or carry objects comfortably. With proper diagnosis and treatment, most people can return to their normal activities and sports with restored strength and function.

If you are experiencing sudden pain, bruising, or weakness in your shoulder or upper arm—especially after sports, lifting, or overhead activity—it may be more than a simple muscle strain. Dr. Brian Waterman, a Board Certified and Fellowship Trained orthopedic surgeon and Sports Medicine expert in Winston-Salem, North Carolina, specializes in diagnosing and treating complex shoulder injuries, including latissimus dorsi and teres major tendon tears. Early evaluation can make all the difference in achieving a safe and full recovery.

Don’t ignore persistent pain or weakness. Contact Dr. Waterman’s office today to schedule a consultation and take the first step toward restoring your strength and returning to the activities you love.