Infraspinatus tendinopathy

Anatomy: Role of the infraspinatus in the rotator cuff

The infraspinatus muscle arises from the infraspinata fossa of the scapula and attaches its tendon to the greater tubercle (large humerus). Together with the supraspinatus, subscapularis and teres minor, it stabilizes the shoulder joint and keeps the head of the humerus centered.

• Main function: external rotation of the upper arm
• Secondary: Fine centering of the humeral head in the socket
• Stress peaks: overhead and throwing sports, repeated external rotation against resistance, long PC activities with the shoulder pushed forward

The infraspinatus tendon is located posterosuperiorly on the head of the humerus - complaints are therefore often felt posteriorly and laterally on the shoulder.

What is Infraspinatus Tendinopathy?

Tendinopathy is a combination of irritation, overload and structural changes to the tendon. It is not just an inflammation, but often a problem in the tendon tissue adapting to repeated stress.

• Acute: sensory overload after unfamiliar activities
• Subacute/chronic: Degenerative remodeling processes, possibly with thickening and reduced resilience
• Differentiation: Tears (partial/complete tears) are separate diagnoses, but can arise from a long-standing tendinopathy

Typical symptoms

• Pain in the back-top or back-lateral side of the shoulder, sometimes radiating into the upper arm
• Reinforcement during external rotation against resistance (e.g. rubber band) or when throwing
• Pain on exertion during overhead activities, side supports, push-ups
• Tenderness over the posterior part of the greater tuberosity
• Night pain when lying on the affected side
• Reduction in the strength of external rotation, rapid fatigue

Neurological symptoms such as tingling in the hand tend to indicate nerve involvement (e.g. cervical spine, suprascapular nerve) and should be differentiated.

Causes and risk factors

• Repetitive overhead strain (volleyball, tennis, CrossFit, crafts)
• Rapid increase in load without adequate adaptation
• Muscle imbalances: weak external rotators/scapular stabilizers, dominant anterior shoulder girdle
• Restricted mobility: tight posterior capsule, reduced thoracic spine mobility
• Impingement mechanisms (tightness under the acromion, posterior-superior impingement when throwing)
• Age and previous shoulder injuries
• Rare: Ganglion cysts in the spino-glenoid notch with suprascapular nerve irritation (isolated infraspinatus atrophy)

Diagnostics in practice

The diagnosis is based on anamnesis, clinical examination and – if necessary – imaging tests. It is important to distinguish it from other causes of shoulder pain such as supraspinatus tendinopathy, biceps tendon problems or nerve bottlenecks.

• Clinical Tests: External Rotation Against Resistance, External Rotation Lag Sign; Hornblower’s Sign speaks more for teres minor involvement
• Functional analysis: scapula control, posture, range of motion, posterior capsule
• Ultrasound: Assessment of tendon thickness, structure, calcifications, tears; dynamic investigation
• X-ray: exclusion of bony factors, calcium deposits, acromion form
• MRI/MR arthrography: in unclear cases, persistent symptoms or suspected partial/complete rupture or nerve compression

In Hamburg, a guideline-oriented examination and – if appropriate – high-resolution ultrasound are available. Imaging is used specifically when it has consequences for therapy.

Conservative therapy: initially gentle and structured

Most infraspinatus tendinopathies respond to conservative measures. The key is an individually controlled stress management with an exercise program, supplemented by short-term symptom control.

• Load adjustment: temporary reduction in pain-causing activities (especially overhead/throwing), not a complete stop
• Pain management: Cooling in the acute phase, if necessary short-term anti-inflammatory medication after consultation with a doctor
• Physiotherapy: Strengthening the external rotators and scapula stabilizers, isometric exercises to modulate pain, later eccentric-concentric strength training
• Mobility: stretching of the posterior capsule and rotator cuff, mobilization of the thoracic spine
• Technology and ergonomics coaching: optimize work and sports technology, break management
• Taping or Kinesio tape: can provide short-term relief (not a replacement for training)

Infiltrations with low-dose cortisone can provide short-term pain relief in selected cases, e.g. B. with accompanying subacromial syndrome. They do not replace the active rehabilitation process and should be used cautiously in terms of frequency and indication.

Regenerative processes: when does it make sense?

If consistent conservative therapy over several weeks to a few months does not bring sufficient improvement and relevant partial tears have been ruled out, regenerative procedures can be considered. The evidence varies depending on the indication.

• PRP (platelet-rich plasma): Discussed as an adjunct to exercise therapy for chronic tendinopathy; Data situation heterogeneous. Decision made individually after informed consent.
• Ultrasound-assisted needle fasciotomy/fenestration: targeted microlesions for new tissue formation; can be considered for stubborn cases.
• Shock wave therapy (ESWT): Evidence from a. for lime shoulders; In the case of pure tendinopathy, the decision is made on a case-by-case basis.

Important: Regenerative measures are supplements. They are particularly useful in combination with a stress-adapted rehabilitation program.

Surgery: rarely necessary

Surgery is the exception for infraspinatus tendinopathy. It can be considered for severe partial or complete tears, persistent pain that limits function despite careful conservative therapy, or for structural causes such as nerve compression caused by ganglion cysts.

• Arthroscopic tendon repair: debridement/refixation for partial tears depending on the size and location of the defect
• Treatment of accompanying pathologies: subacromial decompression in cases of relevant impingement, cyst decompression in cases of suprascapular nerve constriction
• Postoperative rehabilitation: gradual increase in load over weeks to months

The decision is made individually – taking into account complaints, findings and personal goals.

Rehabilitation and training development

Rehabilitation means measured, systematic increase in stress. The aim is to make the tendon resilient again, improve shoulder blade control and strengthen external rotation.

• Stress control: Pain during/24 hours after training is maximally mild and decreasing
• 2-3 units/week of targeted strength training, supplemented by technique and mobility work
• Criteria-based: almost pain-free external rotation strength and endurance, stable scapular control

Self-help: simple exercises for everyday life

These exercises are general and do not replace individual instructions. They should be carried out with little pain and in a controlled manner.

• Warm-up before exercise (5–10 minutes)
• Plan breaks and days off from training
• Have sports and work technique checked (throwing/overhead technique, workplace ergonomics)

Course and prognosis

With consistent conservative therapy, symptoms often improve within weeks. Depending on the initial findings and everyday requirements, full resilience can take several weeks to a few months.

• Early, adapted activity is cheaper than complete rest
• Consistency in exercises and load control has a strong influence on the course
• Relapses are possible, but can be reduced with prevention strategies

Prevention: Keep your shoulders strong and resilient

• Progressive increase in load instead of jump loads
• Regular strength training of the external rotators and scapula stabilizers
• Maintain mobility of the posterior capsule and thoracic spine
• Technical training for overhead sports
• Plan sufficient recovery time

When should medical attention be sought?

• Severe pain or significant loss of strength after trauma
• Severe night pain for weeks
• Sensory disturbances, muscle wasting or persistent weakness in external rotation
• No progress despite load-adapted exercises over 6-8 weeks
• Fever, redness, pain at rest (signs of infection)

Early diagnosis clarifies the cause and prevents lengthy progression.

Related diagnoses and differentiation

• Supraspinatus tendinopathy: more painful on abduction/lateral raises
• Teres minor tendinopathy: pain and weakness in external rotation v. a. in abducted position
• Subscapularis tendinopathy: internal rotation pain, anterior shoulder pain
• Rotator cuff partial/complete tear
• Biceps tendon pathologies (LBS) and instability
• Cervical radiculopathy, suprascapular nerve compression
• Impingement due to calcification or tightness

Information for athletes

The following applies to throwing and overhead sports: dose loads, keep your technique sound and systematically build up your external rotation capacity. A return to play is criteria-based – not calendar-based.

• Monitoring: Pain scale and 24-hour response by units
• Increase load gradually (volume before intensity)
• Integrated program: trunk/scapula stability, rotator cuff strength, thoracic mobility
• Have your throwing or hitting technique checked individually

Your supply in Hamburg

In our orthopedic practice at Dorotheenstrasse 48, 22301 Hamburg, treatment is guided by guidelines and focuses on conservative, active therapy. Ultrasound-supported diagnostics and close collaboration with physiotherapy partners support a structured rehabilitation process.

We will transparently discuss the benefits, limitations and alternatives of individual measures with you - without unrealistic promises of healing. The aim is to accompany you safely and sustainably back into everyday life, work and sport.