Subscapularis Trigger Points
Subscapularis muscle trigger points
Introduction
The subscapularis is a deep rotator cuff muscle responsible for shoulder internal rotation, stabilization, and upper limb control. When trigger points develop in this muscle, they can cause deep shoulder pain, restricted arm movement, and weakness, often mimicking frozen shoulder, rotator cuff injuries, or biceps tendinitis.
Name and Area
Name: Subscapularis
Area: Located on the anterior (underside) of the scapula, running from the subscapular fossa to the lesser tubercle of the humerus.
Indications
Subscapularis trigger points may contribute to:
Deep Shoulder Pain That Feels Like a Constant Ache (Mistaken for Rotator Cuff Injuries or Shoulder Bursitis)
Pain That Extends to the Back of the Shoulder and Upper Arm (Can Mimic Nerve Compression or Biceps Tendinitis)
Restricted Shoulder Movement (Difficulty Reaching Behind the Back or Lifting the Arm Overhead)
Weakness in Shoulder Internal Rotation (Can Affect Throwing, Pushing, or Hugging Movements)
Pain That Worsens with Sleeping on the Affected Shoulder (Common in Side Sleepers and Athletes)
"Frozen Shoulder" Symptoms (Can Feel Like the Shoulder Is "Stuck" or Lacks Full Mobility)
Pain from this muscle is often mistaken for frozen shoulder, rotator cuff injuries, or thoracic outlet syndrome.
Muscle Action
Internally Rotates the Shoulder: Turns the arm inward, essential for throwing, pushing, and hugging movements.
Stabilizes the Shoulder Joint: Prevents excessive movement of the humeral head during arm motion.
The subscapularis is crucial for shoulder function, joint stability, and upper body mechanics.
Signs and Symptoms
Individuals with subscapularis trigger points often report:
Pain in the Front of the Shoulder That Feels Like a "Deep Knot" or Tightness
Pain That Radiates to the Back of the Shoulder and Upper Arm (Can Be Mistaken for Rotator Cuff Issues)
Restricted Shoulder Rotation (Difficulty Reaching Behind the Back, Such as Hooking a Bra or Scratching the Back)
Weakness in Pushing or Throwing Movements (Common in Baseball Players, Swimmers, and Tennis Players)
Pain That Worsens After Long Periods of Shoulder Use, Especially Overhead Activities
Discomfort or Tightness That Makes Sleeping on the Affected Shoulder Painful
Pain worsens with repetitive shoulder use, overhead reaching, or poor posture.
Perpetuating Factors
Common causes of subscapularis trigger points include:
Repetitive Overhead Movements (Common in Swimmers, Baseball Players, Tennis Players, and Weightlifters)
Poor Shoulder Posture (Forward Shoulder Position Can Overload the Subscapularis)
Weak or Imbalanced Rotator Cuff Muscles (Can Cause the Subscapularis to Overcompensate for Shoulder Stability)
Holding the Shoulder in a Fixed Position for Long Periods (Carrying Heavy Bags, Sleeping on One Side, or Driving for Long Hours)
Previous Shoulder Injuries (Can Lead to Chronic Tightness and Reduced Shoulder Mobility)
Trigger Point Referral Pattern
Trigger points in the subscapularis refer pain to:
The front and back of the shoulder (Can Mimic Rotator Cuff Tendinitis or Frozen Shoulder)
The upper arm and back of the elbow (Mistaken for Triceps Pain or Biceps Tendinitis)
The side of the chest (Can Resemble Pectoral Tightness or Rib Dysfunction)
Pain from this muscle is often confused with rotator cuff impingement, nerve compression, or shoulder joint dysfunction.
Differential Diagnosis
Subscapularis trigger points may be mistaken for:
Frozen Shoulder (Adhesive Capsulitis) (Severe Shoulder Stiffness and Limited Range of Motion, Worsens Over Time)
Rotator Cuff Tears (Shoulder Pain and Weakness, Often Worsens with Overhead Movements or Lifting)
Biceps Tendinitis (Pain in the Front of the Shoulder That Extends to the Elbow, Common in Repetitive Lifting Movements)
Thoracic Outlet Syndrome (Pain, Numbness, or Weakness in the Shoulder and Arm Due to Nerve or Vascular Compression)
Pectoralis Major Dysfunction (Chest and Shoulder Pain, Can Lead to Forward Shoulder Posture and Rotational Imbalances)
A thorough shoulder, scapular, and upper limb examination is necessary to rule out these conditions.
Associated Trigger Points
Subscapularis trigger points often co-exist with:
Pectoralis Minor (Anterior Shoulder and Chest Tightness, Can Contribute to Forward Shoulder Posture)
Latissimus Dorsi (Shoulder and Upper Arm Pain, Common in Overhead Athletes and Weightlifters)
Upper Trapezius (Neck and Shoulder Tension, Common in Postural Strain and Stress-Related Pain)
Rhomboids (Scapular and Upper Back Pain, Common in Those with Poor Shoulder Posture and Weak Back Muscles)
Anatomy and Innervation
| Muscle | Origin | Insertion | Innervation |
|---|---|---|---|
| Subscapularis | Subscapular fossa of the scapula | Lesser tubercle of the humerus | Upper and lower subscapular nerves (C5–C7) |
The subscapularis is innervated by the upper and lower subscapular nerves (C5–C7), which also control shoulder stabilization and internal rotation.
Patient Examination
A comprehensive examination should include:
Palpation: Identify tender nodules along the front of the shoulder, under the armpit, and around the scapula.
Resisted Internal Rotation Testing: Assess pain and weakness when rotating the arm inward against resistance.
Scapular Mobility Testing: Look for restricted movement, scapular winging, or compensatory shoulder mechanics.
Shoulder Joint and Rotator Cuff Stability Testing: Rule out impingement, tendon injuries, or capsular restrictions.
Corrective Actions
Dry Needling
Dry needling can release trigger points in the subscapularis, reducing shoulder tightness and improving rotation.
Manual Therapy
Trigger Point Release: Apply deep sustained pressure to tight spots in the subscapularis and anterior shoulder.
Myofascial Release: Helps improve circulation and reduce muscle tension in the shoulder girdle.
Stretching
Doorway Stretch (Chest and Shoulder Opener): Helps release tension in the subscapularis and pectoral muscles.
Sleeper Stretch: Helps increase shoulder internal rotation and flexibility.
Strengthening Exercises
Resisted Internal Rotation With Bands: Strengthens the subscapularis and improves rotator cuff function.
Scapular Stability Exercises (Wall Slides): Helps activate the scapular stabilizers and prevent impingement.
Postural and Movement Adjustments
Avoid Forward Shoulder Posture (Maintain Proper Scapular Position to Prevent Chronic Subscapularis Tightness)
Ensure Proper Shoulder Mechanics During Workouts (Engage the Rotator Cuff Muscles to Reduce Overuse of the Subscapularis)
Use Ergonomic Workstation Adjustments (Prevents Forward Shoulder Posture That Can Exacerbate Shoulder Dysfunction)
Conclusion
The subscapularis plays a crucial role in shoulder stabilization, internal rotation, and upper limb function, but trigger points in this muscle can cause significant shoulder, upper arm, and chest pain. By incorporating dry needling, manual therapy, stretching, and strengthening exercises, individuals can reduce pain, improve mobility, and prevent shoulder dysfunction.
➡️ Learn more about Trigger Points
➡️ Explore our Trigger Point Index
Sources:
Travell, J. G., & Simons, D. G. (1983). Myofascial Pain and Dysfunction: The Trigger Point Manual (2nd ed.). Williams & Wilkins.
Simons, D., & Travell, J. (1999). The Trigger Point Manual, Volume 2: The Lower Extremities. Williams & Wilkins.