• A wrist drop refers to the inability to actively extend the hand at the wrist. Its due to
weakness of the wrist extensors, namely extensor carpi radiallis longus, extensor carpi
radialis brevis and extensor carpi ulnaris muscles, all innervated by the radial nerve or its
• Its usually due to a peripheral neuropathy affecting the radial nerve.
• Wrist drop is a disorder caused by radial nerve palsy. Because of the radial nerves
innervation of the extensor muscles of the wrist and digits, those whose radial
nerve function has been compromised cannot actively extend them. As such, the
hand hangs flaccidly in a position of flexion when the patient attempts to bring
the arm to a horizontal position.
6. RISK FACTORS
• Gender: Radial nerve palsy is more common in men than women.
• Occupational risks: Jobs that require repetitive motion and awkward postures or
working positions may increase the risk of radial nerve palsy.
• Other injuries: fracture midshaft humerus,radius #s, joint dislocations, significant
bruises and injuries requiring the use of crutches can increase a person’s risk for
radial nerve palsy.
7. SIGNS AND SYMPTOMS
• Numbness from the triceps down to the fingers
• Problems extending the wrist or fingers
• Pinching and grasping problems
• Weakness or inability to control muscles from the triceps down to the fingers
• Wrist drop – when the wrist hangs limply and the patient cannot lift it
9. DIAGNOSIS AND INVESTIGATIONS
• To diagnose radial nerve palsy, a physician will perform a physical examination to evaluate weakness,
numbness and other symptoms in the arm and hand.
• Electromyogram (EMG): This test measures the electrical activity of a muscle in response to
stimulation, as well as the nature and speed of the conduction of electrical impulses along a nerve. It
can confirm the presence of nerve damage and assess its severity.
• Imaging studies: The physician may order an X-ray, ultrasound or MRI to check for broken bones,
cysts and other masses in the arm.
• Nerve conduction studies: These tests measure how well individual nerves can send an electrical
signal from the spinal cord to the muscles. A physician places a shock-emitting electrode directly over
the nerve to be studied, and a recording electrode over the muscles supplied by that nerve. The shock-
emitting electrode sends repeated, brief electrical pulses to the nerve, and the recording electrode
records the time it takes for the muscle to contract in response to the electrical pulse
• This condition may go away over time as accompanying injuries heal, cysts or tumors are removed, or
awkward postures are corrected. But, some people may always experience varying degrees of radial
• Treatment and Recovery
• Treatment of radial nerve palsy may include:
• Your physician may recommend prescription or over-the-counter medication to decrease pain
associated with radial nerve palsy.
• Physical Therapy Your physician or physical therapist may prescribe exercises to strengthen your
muscles and increase your range of motion.
• Splint or Cast A splint or cast can support the wrist and hand while the radial nerve heals.
• Surgery In certain cases, your physician may recommend surgery to remove a
cyst, tumor or broken bone pressing on the nerve or repair the nerve itself.
• Transcutaneous Electrical Nerve Stimulation (TENS)
• This therapy applies a gentle electric current to the muscles and may help reduce
• Recovery time depends on how badly the radial nerve was damaged. It may take
weeks to months for a nerve to heal after treatment
• Partial or complte loss of feeling in the hand
• Partial or complete loss of wrist or hand movement
• Mild to severe deformities of the hand eg stiffness, wrist drop
• Recurrent or unnoticed injuries to the wrist or hand