FEATURED ARTICLE • REHABILITATION EDUCATION
Carpal Tunnel Syndrome: Median Nerve Compression, Assessment and Physiotherapy Management
A comprehensive RehabLectures guide for physiotherapy students and clinicians
Introduction
Carpal Tunnel Syndrome (CTS) is described throughout the source material as the most common entrapment neuropathy of the upper limb. It occurs when the median nerve is compressed as it passes through the carpal tunnel at the wrist. The resulting sensory and motor changes can interfere with sleep, gripping, fine hand function and work activities.
Definition and Anatomy
The carpal tunnel is a narrow fibro-osseous canal on the palmar side of the wrist. The carpal bones form its floor and sides, while the transverse carpal ligament, also called the flexor retinaculum, forms the roof.
| Component | Source-derived anatomy |
|---|---|
| Roof | Transverse carpal ligament / flexor retinaculum. |
| Floor and sides | Carpal bones. |
| Contents | Median nerve plus flexor tendons: four FDS tendons, four FDP tendons and one FPL tendon. |
| Median nerve function | Sensory supply to the thumb, index, middle and radial half of the ring finger; motor supply to thenar muscles and relevant lateral lumbricals. |
Pathophysiology
The source describes a sequence in which increased pressure inside the carpal tunnel compresses the median nerve. This can lead to impaired nerve conduction, ischemia and demyelination, with axonal loss appearing in advanced cases. The clinical result is a combination of sensory symptoms and, later, motor weakness or thenar wasting.
Causes and Risk Factors
- Repetitive wrist movements such as typing, writing and tool use.
- Prolonged wrist flexion or extension.
- Manual work and vibrating tools.
- Pregnancy and fluid-retention states.
- Menopause is listed in the source.
- Diabetes mellitus.
- Hypothyroidism.
- Rheumatoid arthritis.
- Obesity.
- Amyloidosis and acromegaly are listed in the source.
- Distal-radius fracture or wrist deformity.
- Other space-occupying or anatomical factors that increase tunnel pressure.
Clinical Features
The characteristic sensory distribution involves the thumb, index finger, middle finger and radial half of the ring finger. The little finger is typically spared because it is supplied by the ulnar nerve. Symptoms are often worse at night and may wake the patient; the source notes that shaking the hand may temporarily relieve symptoms.
- Numbness and tingling in the median-nerve distribution.
- Nocturnal pain or paraesthesia.
- Pain that may radiate into the forearm.
- Weakness of the thumb or difficulty pinching and gripping.
- Dropping objects or reduced fine-motor control.
- Thenar weakness or wasting in chronic/advanced cases.
Assessment: Subjective and Functional Examination
The source emphasizes asking about onset, duration, dominant hand, occupation, repetitive activity, trauma and relevant medical conditions. Functional assessment should consider work, activities of daily living and sleep.
- Symptom distribution and severity.
- Night symptoms and sleep disturbance.
- Typing, writing, gripping and repetitive tasks.
- Dominant-hand involvement.
- History of pregnancy, diabetes, hypothyroidism, rheumatoid arthritis or wrist trauma.
- Functional limitation in work and daily activities.
- Questionnaires such as QuickDASH or the Boston Carpal Tunnel Questionnaire are included in the source as functional options.
Physical Examination and Special Tests
| Test | Procedure | Positive finding |
|---|---|---|
| Tinel’s Sign | Tap over the median nerve at the wrist. | Tingling/paraesthesia in the median distribution. |
| Phalen’s Test | Hold the wrists in flexion for about 60 seconds. | Reproduction of numbness/tingling in the median distribution. |
| Reverse Phalen’s | Hold the wrists in extension for about 60 seconds. | Reproduction of symptoms. |
| Durkan’s / Carpal Compression | Apply direct pressure over the carpal tunnel for about 30–60 seconds. | Reproduction of median-distribution symptoms. |
| Thenar testing | Inspect and test thenar strength, especially thumb abduction/opposition. | Weakness or wasting suggests motor involvement. |
| Two-point discrimination | Assess sensory discrimination in the median-nerve territory. | Abnormal discrimination may indicate sensory impairment. |
Investigations
The source identifies nerve conduction studies (NCS) as the confirmatory or gold-standard investigation used in its notes. EMG can provide additional information, particularly in severe cases. Ultrasound may be used to assess the nerve and wrist structures, while X-ray can help when fracture, arthritis or deformity is suspected.
- Nerve conduction studies — assess sensory and motor conduction across the wrist.
- EMG — may show denervation in advanced cases.
- Ultrasound — may assess the median nerve and carpal tunnel structures.
- X-ray — useful when bony pathology or deformity is suspected.
Differential Diagnosis
The source specifically advises differentiating CTS from other conditions that can produce hand symptoms. These include cervical radiculopathy, diabetic peripheral neuropathy, ulnar nerve entrapment, thoracic outlet syndrome, De Quervain’s tenosynovitis and other wrist/hand disorders.
Clinical pearl: Match the sensory distribution and neurological findings with the suspected nerve. A diagnosis based only on hand pain is incomplete.
Physiotherapy Management
The conservative management described in the source focuses on reducing pressure on the median nerve, improving nerve and tendon mobility, controlling symptoms and restoring hand function.
- Education and activity modification.
- Avoid prolonged or repetitive wrist flexion/extension.
- Frequent breaks during typing or repetitive tasks.
- Ergonomic correction of the workstation and hand position.
- Neutral wrist splinting, especially at night.
- Median nerve gliding exercises when appropriate.
- Tendon-gliding exercises.
- Wrist-flexor and wrist-extensor stretching when appropriate.
- Thenar and grip strengthening once irritability and nerve status permit.
- Symptom-modulating modalities listed in the source include ultrasound, paraffin wax and TENS.
Surgical Management
Carpal tunnel release is included in the source for severe or persistent cases and for cases in which conservative management fails. The operation releases the transverse carpal ligament to reduce compression on the median nerve. Indications listed in the source include persistent symptoms, significant NCS abnormalities and thenar wasting.
Complications and Prognosis
Untreated or advanced CTS may result in permanent median-nerve damage, thenar muscle wasting, loss of thumb opposition, chronic pain and impaired hand function. The source emphasizes that early diagnosis and appropriate management improve the outcome.
Educational Clinical Case: Night Numbness and Weak Grip
Educational clinical example added for RehabLectures to make the article clinically practical. It is not a patient record.
A 48-year-old tailor reports waking at night with tingling in the thumb, index and middle fingers. Shaking the hand gives temporary relief. She has difficulty holding small objects and notices weaker thumb function. Phalen’s and carpal-compression testing reproduce familiar symptoms. The therapist also screens the neck and ulnar-nerve territory before deciding on a management plan.
Clinical reasoning points
- Confirm that the sensory distribution is consistent with the median nerve.
- Assess motor function and thenar status.
- Address repetitive wrist exposure and workstation/task ergonomics.
- Use neutral night splinting and an appropriate exercise program, with referral for further testing when indicated.
Practical Prevention
- Keep the wrist near neutral during repetitive tasks.
- Take regular breaks from typing or manual work.
- Reduce prolonged wrist flexion or extension.
- Use appropriate ergonomic equipment and positioning.
- Begin appropriate rehabilitation early when symptoms appear.
Key Takeaways
- CTS is median-nerve compression within the carpal tunnel.
- Symptoms classically involve the radial three-and-a-half digits and are often worse at night.
- Phalen’s, Tinel’s and Durkan’s tests are useful clinical tests.
- NCS is emphasized in the source as the confirmatory/gold-standard investigation.
- Neutral splinting, activity modification, nerve/tendon gliding and strengthening are important conservative strategies.
- Thenar wasting and persistent severe symptoms warrant specialist evaluation.