Pronator Teres Syndrome ( PTS )

This syndrome ( also known as pronator syndrome ) is uncommon and involves entrapment ( compression or pinching ) of the median nerve at or about the level of the elbow. Depending on the site of entrapment, two types of symptoms may occur. Compression of the median nerve at or just above the elbow leads to weakness of the pronator teres muscle. Median nerve entrapment at the elbow is a rare occurrence and is more commonly seen in children.1

The other site of entrapment is at the pronator muscle itself. Here the median nerve passes between the superficial and deep heads of the muscle and can become entrapped due to edema and hypertrophy ( enlargement ) of the pronator teres muscle. Entrapment at the pronator teres muscle does not involve the muscle since its nervous innervation comes from a point more proximal than the muscle itself sparing the pronator teres muscle.2

Neuropathies ( nerve loss ) at either site will involve both sensory and motor deficits on the flexor ( palm ) side of the forearm. Sensory losses will include the thumb, index and middle fingers, and half the ring finger. This sensory loss typically involves all of the palm of the hand to the wrist. . Sensory losses include numbness, tingling and or pins and needles sensations along the palm of the hand and sometimes part way up the forearm. Motor loss leads to loss of flexion ( inability to make a tight fist ) and opposition of the thumb and fingers involved. The exception to this is as stated above with involvement of the pronator teres muscle which will make it difficult to pronate the arm ( turn the palm down ) .

Pain along the median nerve axis is the most significant feature. It is helped by rest and aggravated by activity. The median nerve is tender along its course ( in the forearm ).3 Symptoms... are reproduced by gripping tightly with resisted pronation of the arm from the elbow to full extension.4

The patient may have a complaint of aching discomfort and easy fatigability of the muscles of the forearm...exacerbated by activities which require repetitive pronation, as in practicing tennis serves or throwing actions.4 Nocturnal awakenings may be seen, but are much less common than in carpal tunnel syndrome.

PTS must be differentially diagnosed from its more common cousin anterior interosseous nerve syndrome ( Kiloh-Nevin Syndrome ). Kiloh-Nevin Syndrome is due to repetitive heavy lifting and is a purely motor dysfunction, affecting flexion of the thumb, distal finger tips of the index and middle fingers and weak pronation of the arm with the elbow flexed. These patients are unable to pinch the fingers together tip-to-tip, but rather can only achieve pulp-to-pulp contact.2

Treatment for PTS involves rest, modification of daily activities, Non-steroidal anti-inflammatory drugs ( NSAIDs ) conservative care and decompressive surgery. Results of decompressive surgery have been variable.4 On the basis of clinical findings, a six month course of conservative treatment is recommended, provided there are minimal or no motor deficits once diagnosis of PTS is made.4

Chiropractic care should be considered as the conservative approach to PTS. Your Chiropractor can aid you by helping to modify your daily activities, providing physical medicine modalities to relax and stretch the pronator muscles to reduce swelling and to aid in the return of movement of the median nerve between the two heads of the pronator teres muscle. Your Chiropractor may massage and mobilize the area as well as use ultrasound to break up adhesions which may be causing entrapment. Also your Chiropractor can manipulate your wrist, elbow, shoulder and neck to help keep the median nerve free in movement along its course.