The condition causing compression or pressure on the radial nerve, resulting in loss of the particular functions pertaining to it is called radial nerve palsy.
The Radial nerve is a branch coming through a bundle of nerves arising from the cervical spinal segment. It crosses the shoulder under the armpits and supplies to the dorsal side of the forearm, from elbow to the tip of the fingers.
This nerve is responsible for sensation in the forearm, as well as, movements like elbow straightening, wrist straightening, and extension of fingers. Whenever the nerve is compressed or damaged at any level, it results in loss of the particular functions pertaining to the nerve.
What are the causes and where can the nerve get compressed?
There are several places where the nerve can get compressed and due to several factors. Some of these are:
- A lesion at axilla/ armpit due to a wound or pressure.
- Use of arm crutches in wrong manner or for a long time exerts very high pressure in the axilla.
- Fractures of arm bone can damage the course of nerve.
- Fractures or dislocations of elbow joint can injure the nerve.
- A common cause is falling asleep with the arm over back of a chair. This has been observed in many alcoholics; hence radial nerve injury is many a times called as ‘Saturday night palsy’.
Symptoms and clinical features of radial nerve compression
- There will be paralysis of muscles of forearm, wrist and fingers which will recover in due course of time.
- The main problem would be the inability to extend or straighten the wrist and fingers.
- The loss of wrist extension will prevent the patient to grip an object adequately, as the wrist muscles work synergistically with muscles required for effective gripping.
- There may be slight weakness in the entire arm.
- Sensory loss will be minimal except more of sensation disturbance in the palm area just below the thumb.
Therapeutic management for radial nerve palsy
It is important to know that the nerve once damaged or compressed, undergoes a lot of anatomical changes. The small nerve fibers have to regenerate themselves in order to start functioning once again and provide motor as well as sensory effects to the forearm, wrist and fingers. This procedure takes about 21 days and the nerve takes over its functions slowly. Hence, this period of three weeks is extremely critical. Taking care of the muscles during this time, so that they are not paralyzed forever, is of prime importance.
Key points to manage radial nerve palsy
Splinting: A functional lively splint which allows movement of forearm and wrist in gripping and bending etc is good to wear. The orthopedician can prescribe a customized splint according to the severity of lesion. Finger movements at short intervals are very important for blood circulation.
Passive movements: This is required to maintain the joint range and the muscle length. Patient can do these movements of wrist, elbow and fingers on his own with help of other hand, but a therapist’s guidance is always good.
Muscle re-education: This is done to make sure muscles do not forget their function i.e. to twitch and contract in the time lost due to compression. Hence, a therapeutic modality called as electrical muscle stimulator is generally given to the patient for 3-4 weeks depending upon recovery. This provides stimulatory effect to the muscles and helps them regain their normal strength.
Therapy after recovery
After slightest normal function of the nerve is observed, patient must be encouraged to perform as many active activities as possible. Most importantly at this time, training with weights must begin and be continued at least for three months.