Muscles Involved in Tennis Elbow
Tennis elbow primarily involves the wrist extensor muscles, with the extensor carpi radialis brevis (ECRB) being the most commonly implicated muscle in this condition. 1, 2
Primary Muscles Involved
- Extensor Carpi Radialis Brevis (ECRB) - The main muscle affected in tennis elbow, with its tendon being the primary site of tendinosis
- Common Extensor Tendon - The shared tendinous origin of the wrist extensor muscles at the lateral epicondyle
- Other Wrist Extensors:
- Extensor Carpi Radialis Longus (ECRL)
- Extensor Digitorum
- Extensor Carpi Ulnaris
Anatomical Considerations
Tennis elbow (lateral epicondylitis) is characterized by:
- Degenerative changes at the enthesis (tendon-bone junction) of the extensor muscles, particularly ECRB 2
- Absence of traditional inflammation, despite the "-itis" suffix in "epicondylitis" 2
- Pain mediation through neurochemicals including glutamate, substance P, and calcitonin gene-related peptide 2
Risk Factors and Mechanism
Tennis elbow develops due to:
- Repetitive wrist extension and flexion activities 1, 3
- Forceful activities involving the forearm 3
- Age over 40 3
- Occupational overuse (manual laborers, workers performing overhead activities) 3
- Racquet sports participation 3
- Poor forearm muscle strength 3
Tennis elbow affects the dominant arm in 75% of cases and is 7-10 times more common than medial epicondylitis (golfer's elbow) 1, 3.
Diagnostic Considerations
- Clinical diagnosis primarily through elimination of other causes of lateral elbow pain 4
- Point tenderness on or near the lateral epicondyle 2
- Pain with resisted wrist extension
- Ultrasound and MRI can help confirm diagnosis in unclear cases 1
- Ultrasound has moderate agreement with MRI for diagnosing common extensor tendon tears (sensitivity 64.52%, specificity 85.19%) 1
Clinical Implications
Understanding the specific muscles involved in tennis elbow helps guide treatment:
- Initial management should focus on physical methods including rest/immobilization 4
- Targeted exercise programs should strengthen the affected wrist extensor muscles 3, 5
- Technique modification for sports and occupational activities can prevent recurrence 3
- Ultrasound therapy has shown effectiveness in controlled trials 4
- Surgical intervention may be considered for persistent cases, though recent evidence questions its superiority over continued conservative care 6
Prevention Strategies
- Modification of physical factors at work or during sports 3
- Improved joint strength through targeted exercises 3
- Biomechanically sound technique in sports and occupational activities 3
Understanding that tennis elbow is a degenerative condition (tendinosis) rather than an inflammatory condition helps guide appropriate treatment approaches focused on tendon healing and strengthening rather than anti-inflammatory measures alone.