An injury to the pronator muscles may be the cause of arm pain. There are many treatment options.
About the Pronator Muscles
There are two pronator muscles in the forearm: the pronator quadratus and the pronator teres. These pronator muscles (along with the supinator muscles) are in charge of pronation, which is important in the rotation of the forearm.1 The pronator teres has a humeral head and an ulnar head. The median nerve comes between the two heads of the pronator teres muscle in the forearm, and it is separated, by the ulnar head, from the ulnar artery. The hand can turn to the posterior, due to the pronator teres. When the elbow is at a right angle, that muscle can turn the palm to the interior. The pronator quadratus assists the larger pronator teres.2
Various Injuries – Flexor and Pronator Strain
Throwing athletes, such as baseball players, can have a high incidence of flexor/pronator strains, due to the repetitive stress. Symptoms of pronator strain could include pain at the inside of the elbow (during the throw) and tenderness in front of the medial epicondyle.3 The purpose of the flexor-pronator muscles is to protect the elbow joint by “countering the torque produced during pitching”. Elbow tendonitis (tendonitis) can result from an injury to this area, which means that there is inflammation.4 Wrist pain could be caused by pronator teres syndrome. In this disorder, patients may experience forearm fatigue, median nerve numbness, and pain.5 PTS “is a painful nerve entrapment condition”. The pronator teres muscle puts pressure on the median nerve, causing pain to the forearm and wrist. It has similarities to carpal tunnel syndrome (CTS) in that it squeezes the nerve, leading to tingling and numbness in the middle finger, forefinger, and palm. Sometimes PTS is misdiagnosed as CTS. Some repetitive stress causes of PTS include overuse of screwdrivers or hand tools, cleaning fish, hammering, and overhead racquet sports. Flexing the elbow, and having symptoms in the hand and forearm, are more indicative of PTS, whereas CTS has less forearm pain and more symptoms arising from wrist movements. PTS is less likely than CTS to cause pain at night.6 A condition called climber’s elbow (or golfer’s elbow) occurs when tendons that connect the pronator teres muscle or forearm flexor muscles to the medial epicondyle region of the inside elbow develop pain. The tendinosis begins with twinges of pain and soreness, while tendinitis has a more acute pain, swelling, and inflammation.7
Treating tendinosis and tendinitis is accomplished in two phases. Phase one aims to reduce inflammation and relieve pain, while phase two is necessary for rehabilitation and stretching. During the first phase, the patient will need to rest, stop engaging in the painful activities, and try icing the injury. NSAIDs, and possibly cortisone injections, may be recommended. This phase could take weeks or months. In phase two, strength-training and stretching exercises are introduced. After 3 or 4 weeks of training without pain, the patient can resume regular activities.8 Massage is another treatment option for PTS.9 Chiropractic treatments could also benefit patients with PTS. Chiropractors can perform active release techniques (ART), which treats the “scar tissue adhesions in and around the pronator teres muscle”. Patients would also be assigned home treatment exercises and activities.10
Find out more about repetitive stress injuries (RSIs).