Radial Nerve Lesion

Upper Limb

Overview

Radial nerve lesion is a peripheral nerve injury affecting motor and sensory function of the dorsal forearm, wrist extensors, and dorsal hand. It commonly results from compression, trauma, or ischemia at various anatomical sites including the axilla, spiral groove of the humerus, or proximal forearm. Clinical presentation varies depending on the level and severity of nerve involvement, ranging from localized sensory loss to profound motor weakness affecting wrist and finger extension.

Pathophysiology

The radial nerve arises from the posterior cord of the brachial plexus (C5-T1) and supplies motor innervation to the triceps, anconeus, wrist extensors (ECRB, ECRL, ECU), finger extensors, and abductor pollicis longus. Compression or injury disrupts axonal conduction, leading to muscle denervation, weakness, and sensory loss in the dorsal first web space and dorsal hand. Depending on lesion location (high vs. low), triceps involvement varies, and recovery depends on nerve regeneration rates and collateral reinnervation.

Patient Education

Understanding your nerve injury level and expected recovery timeline helps guide realistic rehabilitation goals; most nerve injuries show measurable improvement within 3-6 months with consistent therapy, though complete recovery may take 12-18 months.

Typical Presentation

Site

Dorsal forearm, dorsal hand, dorsal first web space; wrist and finger extension weakness; may involve triceps and posterior upper arm depending on lesion level

Quality

Burning or aching pain in dorsal forearm; numbness or tingling in dorsal hand and thumb web space; weakness sensation rather than sharp pain

Intensity

Mild to severe depending on lesion location and severity; pain often 3-6/10, weakness may be complete (0/5) or partial

Aggravating

Resisted wrist extension, finger extension, thumb abduction; gripping activities; pressure over nerve sites (axilla, spiral groove); repeated pronation-supination

Relieving

Rest, immobilization in neutral position, anti-inflammatory measures, nerve gliding exercises, postural adjustments

Associated

Wrist drop (inability to extend wrist), finger drop, thumb abduction weakness, loss of sensation in dorsal web space, triceps weakness if high lesion, absence of wrist extension reflex

Orthopaedic Tests

Test descriptions are written with AI assistance from standard clinical texts. Where a test lists Sources, its description has been checked against them; those sources are independent and do not endorse OsteoKit. Accuracy figures and grades (A–D) appear only when checked against the published study; tests without one are marked “No accuracy study”.

Further reading: full test procedures are described in standard clinical examination texts, e.g. Magee & Manske, Orthopedic Physical Assessment (7th ed.), and Cook & Hegedus, Orthopedic Physical Examination Tests: An Evidence-Based Approach (2nd ed.).

No accuracy study

Wrist Extension Test (Motor)

Procedure

Ask the patient to hold the wrist extended with a fist against your resistance on the back of the hand. Compare with the other side.

Positive Finding

Weak or absent wrist extension (wrist drop).

Interpretation

Wrist drop means a radial nerve lesion above the elbow (often at the spiral groove after a humeral fracture or prolonged pressure, 'Saturday night palsy'). A lesion of the posterior interosseous nerve in the forearm spares wrist extension, because extensor carpi radialis longus is supplied before the nerve divides.

Sources

No accuracy study

Finger Extension Test (Motor)

Procedure

Support the wrist in neutral. Ask the patient to straighten the fingers at the knuckles against your resistance. Compare with the other side.

Positive Finding

Weak or absent extension at the knuckles (finger drop).

Interpretation

Finger drop occurs with both high radial nerve and posterior interosseous nerve lesions. Supporting the wrist is important: with a wrist drop, the fingers look weak because the tendons are slack. Straightening the finger tips (interphalangeal joints) is done by the hand intrinsic muscles and is normal.

Sources

No accuracy study

Thumb Extension Test (Motor)

Procedure

Ask the patient to place the hand flat on the table and lift the thumb up off the table, against light resistance.

Positive Finding

Unable to lift the thumb, or weaker than on the other side.

Interpretation

Tests extensor pollicis longus, supplied by the posterior interosseous nerve. Weakness occurs in high radial and posterior interosseous nerve lesions. Sudden loss of thumb extension after a wrist fracture or in rheumatoid arthritis may be a tendon rupture instead; the tenodesis effect helps separate them.

Sources

No accuracy study

Radial Nerve Sensory Testing

Procedure

Test light touch and pinprick over the back of the first web space (between thumb and index finger), and compare with the other hand.

Positive Finding

Reduced sensation over the back of the first web space.

Interpretation

Sensory loss here comes from the superficial radial nerve, so it occurs with high radial nerve lesions and superficial radial nerve irritation (for example from a tight watch strap). It is absent in posterior interosseous nerve palsy, which is purely motor. Sensory loss that spreads beyond this area suggests a C6/C7 root problem.

Sources

No accuracy study

Triceps and Brachioradialis Screen (Level of Lesion)

Procedure

Test elbow extension (triceps) and elbow flexion with the forearm in mid-position (brachioradialis), and compare with the other side.

Positive Finding

Weakness of triceps and/or brachioradialis.

Interpretation

Helps locate the lesion. Triceps weakness suggests a lesion in the axilla or higher (or a C7 root problem); triceps is usually spared at the spiral groove. Brachioradialis weakness places the lesion above the elbow. Supination is a poor guide, because biceps is a strong supinator.

Sources

No accuracy study

Tinel's Sign at Radial Nerve Sites

Procedure

Tap gently along the radial nerve: at the spiral groove on the back of the arm, at the lateral elbow, and over the superficial radial nerve in the lower forearm.

Positive Finding

Tingling spreading into the back of the thumb or hand.

Interpretation

Suggests nerve irritation at that point, or, after an injury, the level to which the nerve is regrowing (an advancing Tinel sign is a good sign). A radial nerve palsy that does not start to recover within a few months, or any palsy after a fracture, needs specialist follow-up.

Sources

⚠ Red Flags

  • •Signs of spinal cord injury or cervical myelopathy
  • •Progressive neurological deficit despite conservative care
  • •Severe traumatic injury with complete limb dysfunction
  • •Evidence of vascular compromise (pale, cold hand, absent pulses)
  • •Signs of complex regional pain syndrome development
  • •Uncontrolled pain or worsening despite appropriate management
  • •Suspected malignancy or systemic disease causing nerve compression

⚡ Yellow Flags

  • •High anxiety regarding permanent disability or nerve damage
  • •Catastrophizing about loss of hand function
  • •Excessive focus on pain rather than functional recovery
  • •Poor adherence to rehabilitation program
  • •Secondary gain behaviors or symptom magnification
  • •Work-related stress or ergonomic frustration
  • •Previous anxiety or depression affecting coping mechanisms

Osteopathic Techniques

Compressive radial nerve injuries have a good prognosis: with splinting for at least 2–4 weeks, physical therapy and pain relief, most patients recover within about 4 months unless the nerve is torn. Surgery is kept for entrapment that persists for several months. No trials of osteopathic techniques were found.

Safety: Radial nerve palsy is linked to humeral shaft fractures: 15–25% of spiral fractures of the distal third have a radial nerve neurapraxia. After any arm trauma, rule out a fracture before treating.

Safety: Before any neck technique, screen for blood-vessel problems in the neck. If there are signs of myelopathy (see Red Flags), do not treat the neck manually: refer.

Region

Radial nerve (neck to forearm)

Technique

Neural mobilisation, upper limbNo trials found

Rationale

Gentle sliding of the nerve along its path through the neck, arm and forearm.

How it's done & evidence

How it's done

A movement-based treatment aimed at the nerve and the tissues around it. Gentle, rhythmic neck and arm movements either slide the nerve along its path (sliders) or lightly tension it (tensioners), with a median, radial or ulnar bias. One review found sliders helped more in acute pain and tensioners in chronic pain.

Evidence in Radial Nerve Lesion

Searched 26 Oct 2026: no trials of neural mobilisation in radial nerve palsy.

Region

Cervical spine and brachial plexus region

Technique

Soft tissue, neck and shoulder girdleNo trials found

Rationale

Soft tissue to the neck and scalene muscles along the brachial plexus.

How it's done & evidence

How it's done

Hands-on soft-tissue work (kneading, stretching and sustained pressure) across or along the cervical paraspinals, upper trapezius and levator scapulae, usually with the patient supine.

Evidence in Radial Nerve Lesion

Searched 26 Oct 2026: no trials of neck soft tissue in radial nerve palsy.

Sources

Region

Posterior shoulder and axilla

Technique

Soft tissue, shoulder and periscapular musclesNo trials found

Rationale

Soft tissue to the shoulder girdle and rotator cuff muscles.

How it's done & evidence

How it's done

Hands-on kneading, stroking and sustained pressure to the muscles around the shoulder: the rotator cuff, deltoid and the muscles around the shoulder blade. In trials it was given alongside shoulder exercise.

Evidence in Radial Nerve Lesion

Searched 26 Oct 2026: no trials of shoulder soft tissue in radial nerve palsy.

Region

Cervical and upper thoracic spine

Technique

Articulation, cervicalNo trials found

Rationale

Gentle cervical and upper thoracic articulation for the segments that supply the arm.

How it's done & evidence

How it's done

Rhythmic, low-velocity movement of a restricted cervical segment within its passive range, with no thrust. Usually done with the patient supine and the head supported; the amplitude can vary.

Evidence in Radial Nerve Lesion

Searched 26 Oct 2026: no trials of cervical mobilisation in radial nerve palsy.

Sources

Rehabilitation Exercises

Passive Wrist Extension Mobilization

Range of MotionBeginner

Gravity-Reduced Finger Extension in Supination

Range of MotionBeginner

Nerve Gliding Sequence (Radial Nerve Mobilization)

StretchingBeginner

Pronator Stretch in Cervical Neutral

StretchingBeginner

Active Assisted Wrist Extension

StrengtheningBeginner

Finger Extensor Strengthening with Rubber Band Resistance

StrengtheningIntermediate

Thumb Abductor Strengthening (Abductor Pollicis Longus)

StrengtheningIntermediate

Progressive Wrist Extension Against Resistance

StrengtheningIntermediate

Scapular Stability and Posture Retraining

PosturalBeginner

Cervical Posture and Neutral Spine Awareness

PosturalBeginner

Proprioceptive Retraining - Hand Sensation Activities

BalanceIntermediate

Functional Graded Grasp and Release Activities

FunctionalIntermediate

Referral Criteria

  • •Complete radial nerve palsy with no sign of recovery after 8-12 weeks
  • •Severe traumatic injury with suspected nerve transection requiring surgical consultation
  • •Progressive neurological deficit despite conservative management
  • •Development of complex regional pain syndrome features
  • •Concurrent cervical spine pathology affecting brachial plexus
  • •Signs of vascular compromise requiring vascular surgery assessment
  • •Psychological distress or maladaptive pain behaviors requiring mental health support
  • •Need for electrodiagnostic studies (EMG/NCS) to confirm diagnosis and lesion location
  • •Consideration of surgical exploration or nerve repair if appropriate timeline and imaging findings support intervention