Comprehensive Study Notes on Shoulder Injuries

Chapter 14: Shoulder Injuries

Overview of Shoulder Anatomy

  • Shoulder Overview
    • Ball-and-socket joint.
    • Provides significant mobility but limited stability.
    • Humeral head sits in the glenoid fossa.
    • Shoulder girdle comprises three bones:
    • Humerus: features the bicipital groove at the top.
    • Clavicle: commonly known as the collarbone.
    • Scapula: also referred to as the shoulder blade.

Shoulder Joint Type and Mobility

  • Types of Joints
    1. Sternoclavicular joint
    2. Acromioclavicular joint
    3. Scapulothoracic joint
    4. Glenohumeral joint

Shoulder Ligaments

  • Acromioclavicular Ligament

    • The most commonly injured ligament.
    • Connects the clavicle to the acromion process of the scapula.

  • Coracoacromial Ligament

    • Connects the coracoid process to the acromion process.
    • Frequently injured in grade III sprains.

  • Transverse Ligament

    • Functions to stabilize the biceps tendon.

Shoulder Muscles

  • Muscle Groups
    • Rotator Cuff Muscles (Acronym: S.I.T.S.)
    • Supraspinatus
    • Infraspinatus
    • Teres minor
    • Subscapularis
    • Additional Muscles
    • Deltoid
    • Biceps
    • Triceps

Additional Shoulder Ligaments

  • Acromioclavicular (AC) Ligament

    • Links the acromion on the scapula to the distal clavicle.

  • Glenohumeral Ligament

    • Connects the glenoid fossa on the scapula to the humeral head.
    • Part of the capsular ligament that stabilizes the shoulder joint.

Shoulder Motions

  • List of Shoulder Movements
    1. Shoulder Flexion
    2. Shoulder Extension
    3. Shoulder Abduction
    4. Shoulder Adduction
    5. Shoulder Internal (Medial) Rotation
    6. Shoulder External (Lateral) Rotation
    7. Horizontal Abduction
    8. Horizontal Adduction
    9. Circumduction

Types of Shoulder Sprains

  • Sprains
    • Acromioclavicular or Shoulder Separation: Injury at the AC joint.
    • Glenohumeral Dislocation: Dislocation or subluxation with potential for glenoid labrum damage.
    • Sternoclavicular Injuries: Can lead to compression of the trachea, particularly if posterior; watch for emergency scenarios due to proximity to cardiorespiratory structures.

Bursae of the Shoulder

  • Function of Bursae: Cushions between muscles and bones, assisting in movement and reducing friction.
    • Key Bursae
    • Subacromial bursa
    • Subcoracoid bursa
    • Subdeltoid bursa
    • Subscapularis bursa

Preventing Shoulder Injuries

  • Key factors contributing to shoulder injuries:

    • Muscle weakness
    • Postural problems associated with activities.

  • Postural Dynamics

    • Weight at the head increases by an additional 13 pounds for every inch of forward head posture.

Addressing Muscle Weakness and Posture

  • Recommendations
    • Focus on all muscle groups, not just visually apparent ones.
    • Balance anterior and posterior muscle strength:
    • Stretch tight muscles.
    • Strengthen weak muscles.
    • Maintain a proper posture:
    • Keep the chest up and shoulder blades together.

Sport-Specific Concerns

  • Vulnerable Athletes: Swimmers and throwers identified as "overhead athletes."
  • Strength Training Guidance:
    • Incorporate counterbalance strengthening exercises targeting opposing muscle groups.
    • Include training for smaller stabilizing muscles.
    • "Thrower’s Ten" program is recommended for this demographic.

Protective Measures for Shoulder Injuries

  • Protective Equipment:
    • Appropriately use shoulder pads.
  • Modification Recommendations:
    • Differentiate types of throwing, limit intensity of hits, etc.
    • Monitor pitch counts, serves, hits, and spikes.
    • Young athletes should have baseline activity adjustments, such as "kicking only" days in swimming.
    • Emphasize the importance of rest.

Bone Injuries in the Shoulder

  • Clavicular Fractures:

    • The distal third of the clavicle is most vulnerable.
    • Symptoms: obvious deformity, point tenderness, and limited range of motion (ROM).
    • Treatment options include the use of a sling or surgical interventions if necessary.

  • Humeral Fractures:

    • Often occur at the midshaft.
    • May include epiphyseal (growth plate) injuries; caution is advised with young athletes.
    • Symptoms include pain and an inability to use the arm.
    • Avulsion Fractures: Small fragments of bone may pull, affecting glenoid or acromion.

Shoulder Dislocations

  • Subluxation vs Dislocation:
    • Subluxation: the joint goes out but reduces on its own.
    • Dislocation: the joint dislocates and remains out of alignment.
  • Complications:
    • Awareness of potential bone and nerve damage.
    • Medical professionals must be consulted to reduce a glenohumeral dislocation or subluxation.

Examination Questions on Shoulder Dislocations

  • Concepts to consider:
    1. What structures help secure the shoulder in place?
    2. What is the most common direction of a shoulder dislocation?
    3. Besides the labrum, what other structures may be injured during dislocation?
    4. What is the timeline for an athlete's return to sports post-surgery?

Rotator Cuff Management

  • Rotator Cuff Strain:
    • Strains graded similarly to other tissue injuries.
    • Often results from excessive range of motion.
    • Main symptom is pain during abduction.
    • Recommended treatment includes PRICES (Protection, Rest, Ice, Compression, Elevation) and gentle exercise.

Impingement Syndrome

  • Conditions and Symptoms:
    • Caused by repetitive overhead motions.
    • Special tests include the Hawkins-Kennedy test and horizontal adduction, which elicits pain in the subacromial space.
    • Symptoms include compression of the supraspinatus and biceps as they pass through the subacromial area.
  • Management:
    • Modify exercises, employ PRICES, and focus on proper posture to alleviate symptoms.

Scapular Winging

  • Definition and Cause:

    • Scapular winging occurs due to weak scapular stabilizing muscles, predominantly the serratus anterior.

  • Corrective Exercises:

    • Serratus punches
    • Elevated push-ups with a plus
    • Plank scapular protraction/retraction; add push-ups with a plus for efficacy.

Biceps Tendonitis and Rupture

  • Common Conditions:
    • Biceps tendonitis frequently arises from racket sports and repetitive motion activities.
    • Symptoms may include a sensation of crepitus, or crunching within the tendon.
    • Rupture often occurs under excessive force or contraction, leading to inability to flex the elbow, often with visible muscle retraction at a bulged area of the arm.

Thoracic Outlet Syndrome

  • Pathophysiology:
    • Condition arises when the area between the first rib and clavicle narrows, leading to compression of neurovascular structures.
    • Symptoms include numbness and discoloration in the hand and arm.
  • Referral: Must be referred to a medical doctor for detailed evaluation and treatment.

Summary of Shoulder Injuries

  • Key Concept: The shoulder is complex and extremely mobile.
  • Common Causes of Injuries: Often result from repetitive stress linked to activities such as overhead motions, throwing, and swimming.
  • Treatment Parameters: Should prioritize not only immediate management of the injury but also focus on strengthening and flexibility improvement to prevent future injuries.
  • Fundamental Principles: Maintaining proper posture and biomechanics throughout sports activities is crucial for effective injury treatment and rehabilitation.