Tear of the Subscapularis Muscle: Symptoms, Diagnosis, and Treatment

What Is the Subscapularis Muscle?

The subscapularis muscle is a crucial muscle in your shoulder and a key component of the rotator cuff. Think of the rotator cuff as a team of four muscles and tendons that stabilize and move your shoulder. The subscapularis is the largest and strongest member of this team. It sits directly under your shoulder blade (scapula) and is the only rotator cuff muscle that attaches to the inner surface of your shoulder blade.

Its main job is internal rotation of your arm—the motion you use when you bring your hand toward your chest or stomach. It also acts as an essential stabilizer, keeping the head of your upper arm bone centered in the shoulder socket, especially when you move your arm. Without a functioning subscapularis, your shoulder would be unstable and wouldn’t move smoothly.

Causes and Types of Subscapularis Tendon Tears

A subscapularis tendon tear occurs less often on its own than a tear of the supraspinatus tendon, but it is often more serious because it severely weakens the front stability of your shoulder.

Acute Traumatic Tears

This type of tear usually results from a direct, forceful event, such as a fall onto an outstretched arm or a sudden, uncontrolled outward rotation. Imagine trying to catch a heavy object and your shoulder is abruptly pulled outward. In these cases, the tear is often a complete (full-thickness) subscapularis tendon tear, leading to immediate severe pain and loss of function.

Degenerative Tears

Far more commonly, a tear develops from wear and tear (degeneration) over many years. Repeated micro-traumas, common in overhead sports (swimming, tennis, baseball) or certain jobs (painting, electrical work), gradually weaken the tendon. Over time, the tendon tissue becomes brittle. This typically starts as a partial subscapularis tendon tear, affecting only part of the tendon.

Associated Injuries

A subscapularis tendon tear rarely happens in isolation. In up to 80% of cases, the long head of the biceps tendon is also involved, either torn from its anchor (biceps tendon dislocation) or inflamed. The front of the shoulder capsule or the labrum can also be affected.

Symptoms: How to Recognize a Subscapularis Tear

The symptoms are often clear and can help you act quickly and seek medical advice. Watch for these signs:

Pain at the Front of the Shoulder

Pain is typically felt deep in the front of the shoulder and may radiate down the arm. It becomes especially noticeable when you:

Reach your arm behind your back, like to tuck in a shirt or fasten a bra.
Strongly rotate your arm inward.
Lie on the affected side at night. This is a very common sign of rotator cuff problems.

Significant Weakness in Internal Rotation

The subscapularis is the primary internal rotator. With a tear, you will notice marked weakness or an inability to turn your arm inward against resistance. Everyday tasks requiring this motion become suddenly very difficult:

Fastening a bra (for women).
Putting on or taking off a jacket.
Holding a heavy object close to your body.

Instability and Clicking

A feeling of instability or an audible clicking sensation in the shoulder joint may occur, especially if the long biceps tendon is also dislocated. The upper arm bone is no longer properly centered. If you feel a tearing or popping sensation in your shoulder, it could be an acute subscapularis tendon tear.

Specific Diagnostic Tests

Your doctor or therapist will not only check your general range of motion but will perform specific orthopedic tests that target the subscapularis muscle and its tendon. These tests are essential for an accurate diagnosis of a subscapularis tendon tear.

The Lift-Off Test (Gerber Test)

This is the classic test for the subscapularis. You place your hand behind your back with the back of your hand facing away from your body. Then, you try to actively lift your hand away from your back.

Positive: If you cannot lift your hand off your back or the movement is very weak, this suggests a tear.

The Belly-Press Test

If you cannot reach your arm far enough behind your back (due to pain or other injuries), the belly-press test is used. You press the palm of your affected hand against your stomach.

Positive: If you lack the strength and your elbow drops backward, or you have to bend your wrist to maintain pressure, this is a strong indicator of a subscapularis tendon tear.

The Bear-Hug Test

You place the palm of your affected hand on your opposite shoulder. Your doctor then tries to pull your hand away from your shoulder.

Positive: If you cannot hold this position and your strength gives way, this often confirms damage, particularly to the upper part of the subscapularis.

Imaging Studies

Ultrasound (Sonography): Useful for a quick initial assessment of the tendon and its integrity.
MRI (Magnetic Resonance Imaging): This is the gold standard for diagnosis. An MRI can show the exact size of the tear (partial vs. complete), the quality of the remaining muscle tissue (fatty degeneration), and any associated damage (biceps tendon, cartilage). This is essential for deciding between conservative and surgical treatment for a subscapularis tendon tear.

Treatment Options: From Conservative Care to Surgery

Treatment depends on the extent of the tear, your age, your activity level, and how long you have had symptoms.

Conservative (Non-Surgical) Treatment

This option is usually considered for small, partial tears or in older, less active patients with minimal functional limitation.

Phase 1: Pain Reduction and Inflammation Control

The focus is on rest and offloading the tendon.

Rest and Activity Modification: Avoid all movements that trigger pain, especially forceful internal rotation.
Medication: Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen can help with pain and inflammation.
Injections: A corticosteroid injection into the joint space can provide rapid relief for acute pain in some cases, but should be used sparingly due to the potential risk of weakening the tendon.

Phase 2: Restoring Passive and Active Range of Motion

Once pain subsides (often after 2-4 weeks), gentle mobilization begins under the guidance of a physical therapist.

Passive Mobilization: The therapist moves your arm without engaging the subscapularis muscle.
Active-Assisted Exercises: You help slightly with the movement. The goal is to regain full range of motion in all directions without overloading the healing tendon.

Phase 3: Targeted Strengthening and Stabilization

This phase is critical for long-term success and preventing a recurrent subscapularis tendon tear.

Strengthening the Antagonists: The external rotators (infraspinatus, teres minor) and the deltoid are strengthened first to stabilize the shoulder joint.
Isometric Subscapularis Exercises: Later, careful isometric exercises (contracting the muscle without movement) for the subscapularis are introduced. Examples include pressing your hand against a wall or your own stomach.
Functional Training: Integrating movements into sport- or work-specific activities.

Surgical Treatment

Surgery is necessary for:

Full-Thickness Tear: When the subscapularis tendon tear is complete and significantly limits function.
Failure of Conservative Therapy: When six weeks to three months of non-surgical treatment does not bring sufficient improvement.
Active, Young Patients: If you are younger, very active, and need to regain full shoulder strength.

Specific Surgical Methods

A subscapularis tendon tear is now almost always repaired arthroscopically (minimally invasive).

Arthroscopic Tendon Repair: Through small incisions, specialized suture anchors (made of titanium or absorbable material) are placed in the upper arm bone. The torn tendon is then sutured back securely to its original attachment point.
Biceps Tendon Tenodesis/Tenotomy: Because the long head of the biceps tendon is almost always involved, it is often treated at the same time to relieve pain and improve stability. It is either shortened and re-anchored (tenodesis) or simply cut (tenotomy).
Reconstruction: For a very large, chronic subscapularis tendon tear, it may be necessary to use tendon tissue from another site (tendon transfer) because the original tendon is severely shortened and degenerated.

Post-Surgical Rehabilitation and Full Recovery

After surgery, a long but necessary rehabilitation phase begins. Patience is key, as the repaired tendon needs time to heal.

First 6 Weeks: Immobilization

Immediately after surgery, you will wear an arm sling (abduction pillow) that holds your arm in a slightly elevated position.

Goal: Absolute protection of the tendon repair. No active movement of the arm!
Exercises: Only gentle pendulum exercises are allowed, along with moving your hand, wrist, and elbow.

Weeks 7 to 12: Passive and Active Range of Motion

The sling is gradually discontinued. The focus now is on restoring range of motion.

Passive Exercises: Physical therapy begins with gently moving the shoulder passively in all directions to prevent stiffness (frozen shoulder).
Active Exercises (No Resistance): You begin moving your arm without weight or resistance. Active internal rotation is still high-risk and is usually introduced very late.

Weeks 13 to 24: Targeted Strength Building

This is the phase where you regain muscle strength.

Resistance Training: You begin with light resistance bands and dumbbells to strengthen all the rotator cuff and shoulder girdle muscles. The subscapularis tendon tear is now stably healed.
Core and Posture Control: A strong core is essential for a stable shoulder.
Functional Training: Sport- or work-specific movements are practiced under low load.

Recovery Timeline: When Will You Be Fit Again?

Conservative Treatment: 4 to 6 months until you can perform normal daily activities pain-free.
Surgical Repair: It often takes 6 to 9 months to feel safe during daily activities, and up to 12 months for a full return to overhead sports or heavy lifting. Success depends heavily on how diligently you follow your rehabilitation program. A recurrent subscapularis tendon tear must be avoided at all costs.

Prevention Tips: How to Protect Your Tendon

Prevention is always the best treatment. Especially if you are prone to overhead activities, take proactive steps.

Posture and Balance

Good Posture: Maintain an upright posture. A slouched forward posture (rounded shoulders) narrows the space under the shoulder blade and can irritate the tendons (impingement).
Rotator Cuff Balance: Regularly perform exercises to strengthen your external rotators (infraspinatus and teres minor). These are often the weaker counterparts to the subscapularis, and an imbalance can lead to incorrect loading.

Training and Load Management

Warm-Up: Always take time for a dynamic shoulder warm-up before any activity or sport.
Technique: Focus on correct exercise form. Have a coach check your technique, especially for throwing or weightlifting.
Recovery: Avoid overtraining. Adequate rest between intense sessions is essential for tendon health. Tendons take longer to recover than muscles.

When You Absolutely Must See a Doctor

Do not hesitate to see an orthopedist or shoulder specialist if you experience:

Sudden, severe shoulder pain, possibly accompanied by a “pop” sensation.
Significant, persistent weakness, especially with internal rotation or if you can barely lift your arm away from your body.
Pain that lasts longer than a week despite rest and over-the-counter pain relievers.

Conclusion: A subscapularis tendon tear is a serious injury, but with the right diagnosis, a tailored treatment plan—whether conservative or surgical—and your dedicated effort in rehabilitation, you have an excellent chance of regaining full or near-full shoulder function. Always seek professional advice to find the best path for you.