Deltoid Trigger Points

Introduction

The deltoid is a large, triangular muscle that covers the shoulder joint, playing a major role in arm movement and shoulder stability. When trigger points develop in this muscle, they can cause pain in the shoulder, upper arm, and difficulty lifting the arm, often mimicking rotator cuff injuries, bursitis, or nerve impingement syndromes.

Name and Area

  • Name: Deltoid

  • Area: Covers the shoulder joint, spanning from the clavicle and scapula to the humerus. It has three distinct sections:

    • Anterior Deltoid: Located at the front of the shoulder.

    • Lateral (Middle) Deltoid: Located on the outer shoulder.

    • Posterior Deltoid: Located at the back of the shoulder.

Indications

Deltoid trigger points may contribute to:

  • Pain in the Outer Shoulder and Upper Arm (Mimicking Rotator Cuff Issues)

  • Pain When Lifting the Arm or Reaching Overhead

  • Weakness in Shoulder Movements (Difficulty Lifting or Carrying Objects)

  • Pain That Radiates Down to the Upper Arm (Mistaken for Biceps or Triceps Issues)

  • Stiffness or Discomfort After Prolonged Shoulder Use (Throwing, Lifting, or Holding a Position)

  • Pain While Sleeping on the Affected Side

Pain from this muscle is often mistaken for bursitis, tendonitis, or nerve compression.

Muscle Action

  • Anterior Deltoid: Flexes and internally rotates the shoulder.

  • Lateral Deltoid: Abducts the arm (raises it sideways).

  • Posterior Deltoid: Extends and externally rotates the shoulder.

The deltoid is critical for lifting, throwing, and stabilizing the shoulder joint.

Signs and Symptoms

Individuals with deltoid trigger points often report:

  • Pain in the Outer Shoulder That Doesn’t Extend Past the Elbow

  • Weakness or Fatigue When Raising the Arm (Especially Sideways or Forward)

  • Pain When Carrying Heavy Objects, Particularly at Arm’s Length

  • Sharp Pain or Discomfort When Throwing or Lifting Overhead

  • Pain While Sleeping on the Affected Shoulder

Pain increases with repetitive arm movements, lifting, or prolonged shoulder use.

Perpetuating Factors

Common causes of deltoid trigger points include:

  • Repetitive Overhead Activities (Weightlifting, Swimming, Painting, Baseball, Tennis, Volleyball)

  • Carrying Heavy Loads With the Arm Extended (Suitcases, Grocery Bags, Backpacks)

  • Holding the Arm in a Raised Position for Long Periods (Driving, Holding a Phone, Using a Mouse at Shoulder Height)

  • Previous Shoulder Injuries (Rotator Cuff Tears, Dislocations, Bursitis, or Fractures)

  • Poor Posture or Shoulder Imbalances (Rounded Shoulders, Forward Head Posture, or Weak Scapular Muscles)

Trigger Point Referral Pattern

Trigger points in the deltoid refer pain to:

  • The outer shoulder (Deltoid Region, Mistaken for Bursitis or Rotator Cuff Tendinitis)

  • The upper arm, sometimes extending to the elbow

  • The front, side, or back of the shoulder depending on which section is affected

Pain from this muscle is often confused with nerve compression, rotator cuff injuries, or bicipital tendinitis.

Differential Diagnosis

Deltoid trigger points may be mistaken for:

  • Rotator Cuff Tears or Tendinitis (Pain With Overhead Movements, Shoulder Weakness, Clicking or Popping Sounds)

  • Subacromial Bursitis (Pain in the Outer Shoulder, Worse When Lying on the Affected Side)

  • Axillary Nerve Entrapment (Numbness, Tingling, or Weakness in the Shoulder and Upper Arm)

  • Frozen Shoulder (Adhesive Capsulitis, Severe Shoulder Stiffness and Limited Range of Motion)

  • Cervical Radiculopathy (C5 Nerve Root Compression, Causing Shoulder and Upper Arm Pain)

A thorough shoulder and upper arm assessment is crucial for correct diagnosis.

Associated Trigger Points

Deltoid trigger points often co-exist with:

  • Supraspinatus (Shoulder Abduction Weakness and Upper Arm Pain)

  • Infraspinatus (Pain in the Posterior Shoulder and Arm, Weak External Rotation)

  • Trapezius (Pain in the Shoulder, Upper Back, and Neck Stiffness)

  • Biceps Brachii (Anterior Shoulder Pain and Forearm Weakness)

Anatomy and Innervation

Muscle Origin Insertion Innervation
Anterior Deltoid Clavicle Deltoid tuberosity of humerus Axillary nerve (C5–C6)
Lateral Deltoid Acromion (Scapula) Deltoid tuberosity of humerus Axillary nerve (C5–C6)
Posterior Deltoid Spine of the scapula Deltoid tuberosity of humerus Axillary nerve (C5–C6)

Patient Examination

A comprehensive examination should include:

  • Palpation: Identify tender nodules in the front, side, or back of the shoulder.

  • Resisted Shoulder Flexion, Abduction, and Extension Testing: Assess pain and weakness in different shoulder movements.

  • Scapular Stability Testing: Check for muscle imbalances that may be affecting deltoid function.

  • Range of Motion Assessment: Look for limitations in overhead, lateral, or rotational movements.

Corrective Actions

Manual Therapy

  • Trigger Point Release: Apply sustained pressure along the deltoid muscle belly.

  • Myofascial Release: Stretch and mobilize surrounding shoulder and scapular muscles.

Stretching

  • Shoulder Flexion Stretch: Extend the arm backward to stretch the anterior deltoid.

  • Lateral Shoulder Stretch: Bring the arm across the body to stretch the lateral and posterior deltoid.

  • Chest and Shoulder Stretch: Use a doorway stretch to open up the front of the shoulder.

Strengthening Exercises

  • Lateral Raises (With Light Weights): Strengthens the middle deltoid.

  • Face Pulls: Improves posterior deltoid and scapular stability.

  • Front Raises: Strengthens the anterior deltoid for better shoulder control.

Postural and Ergonomic Adjustments

  • Modify Overhead Lifting Techniques (Reduce Strain on the Shoulder Joint)

  • Improve Desk Ergonomics (Avoid Holding the Shoulder in a Fixed Position for Long Periods)

  • Use Proper Sleeping Positions (Avoid Sleeping on the Affected Shoulder)

Field Details
Name & Area Deltoid; Shoulder region, covering the glenohumeral joint
Indications Shoulder pain, difficulty lifting arm, upper arm discomfort
Muscle Action Shoulder flexion, abduction, extension, and rotation
Signs & Symptoms Pain in the outer shoulder, weakness in arm movements, pain when sleeping on the affected side
Perpetuating Factors Overhead lifting, repetitive shoulder use, carrying heavy loads, poor posture
Trigger Point Referral Outer shoulder, upper arm, lateral elbow
Differential Diagnosis Rotator cuff injury, bursitis, nerve compression, frozen shoulder
Associated Trigger Points Supraspinatus, infraspinatus, trapezius, biceps brachii
Anatomy & Innervation Axillary nerve (C5–C6)
Corrective Actions Manual therapy, stretching, strengthening, ergonomic modifications

Summary Table: Deltoid Trigger Points

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.