What Is Hand Pronation?

In order to cause the internal rotation of the joint, the muscle generally crosses the front of the vertical axis of the joint, such as the pronator muscle and anterior muscle.

In order to cause the internal rotation of the joint, the muscle generally crosses the front of the vertical axis of the joint, such as the pronator muscle and anterior muscle.

Chinese name

Pronator

Foreign name

pronator

Pronator- related auxiliary structures

Some researchers have found that the median nerve in 85% of anatomical specimens must pass between the two heads of the pronator circular muscle before passing through the deep side of the superficial flexor tendon arch (the so-called "superficial bridge"). Occasionally, the anterior spinalis muscle is connected to the "shallow bridge" of abnormal fiber bands that can damage the median nerve. Near the penetrating pronator muscle, the median nerve branches to the elbow joint, pronator muscle, radial flexor carpi flexor, longus flexor and superficial flexor flexor. Later, the interosseous volar nerve is issued, which often innervates the long flexor hallucis longus, the deep flexor muscle and the anterior rotator muscle. This nerve is located in front of the forearm interosseous membrane. The median nerve trunk walks in the deep side of the superficial flexor muscles in the forearm, and sends a sensory branch to the humeral hump on the wrist. This branch passes through the shallow side of the flexor support band, so it is not affected by carpal tunnel syndrome. Involved. After entering the hand, the median nerve innervates the first and second vermiform muscles and all interclinical muscles except the adductor hallucis.

Pronator pronator syndrome

1. Pronator syndrome is due to fascia and tendon stenosis in the proximal portion of the pronator circular muscle, and compression of the median nerve causes the patient to have pronator tenderness, weakness of the flexor hallucis longus and abductor hallucis, and pain and discomfort in the forearm , Hand weakness and numbness of the thumb and index finger. In patients with pronator muscle syndrome, the conduction velocity of the median nerve in the forearm of the forearm is slower, but the distal latent period and the action potential of the sensory nerves in the wrist are normal.

2. Treatment of pronator syndrome

(1) Non-surgical therapy: conservative treatment for local closure. Some researchers believe that non-surgical treatment is valuable and should be tested in every case. The method is: inject corticosteroids into the pronator round muscle, if the response is not complete, it should be repeated. If possible, patients should avoid strenuous post-flexion movements.

(2) Surgical treatment: If the patient is not fully relieved by conservative treatment, or his work causes symptoms to worsen repeatedly, it is advisable to explore the pronator area and surgically isolate any bands or compressive lesions. For fascia or tendon stenosis, release decompression.

3. The symptoms of carpal tunnel syndrome and pronator muscle syndrome are similar. Therefore, the differential diagnosis of the two is more difficult. There is tenderness on the proximal side of pronator muscle syndrome. When fighting forearm pronation, elbow flexion, or contraction of the superficial digital muscles, the tenderness and other forearm symptoms can be aggravated. The difference between carpal tunnel syndrome and pronator muscle syndrome is that it gets worse at night, which is more obvious when the temperature of the hand increases.

Pronator- related diseases

Humeral epicondylitis is a common common elbow injury in the elderly, with a high incidence on the outside, about 4-7 times the inside. Smoking, obesity, repetitive or hard movements are all significantly related to medial epicondylitis, and are the main cause of pain on the inside of the elbow joint. They most often occur at the tendon stops of the radial flexor carpal flexor and pronator. The incidence rate in the general population is 0.3% to 1.1%, and the incidence rate among golf and baseball players has increased to 13.5% to 27.3%. Pain when flexing the wrist or forearm pronation. Epicondylitis of the humerus is not an inflammatory response, but a degenerative change, because inflamed cells are rarely seen under the microscope. Mainly due to repeated contraction or overuse of the flexor wrist muscles, forearm pronation muscles, micro tears at the epicondyle attachment of the humerus, such as scarring or adhesion caused by non-healing, normal biomechanical changes, and long-term epicondyle Muscle and tendon junctions degenerate, and the most common location is the pronator round muscle and radial wrist flexion muscle attachment.

Pronator related clinical applications

1. The sequelae of cerebral palsy causes physical disability, which has severely affected the lives of society, families and individuals. In clinical work, some researchers have performed surgery for pronator muscle resection and tendon displacement for patients with cerebral palsy sequelae for forearm supination and hallux abduction dysfunction. Through surgery, the factors hindering the supination of the forearm were removed, and the abduction function of the thumb was reconstructed, thereby restoring the supination function of the forearm and the hand-holding ability of the hand. The surgical treatment of forearm pronation deformity of the sequelae of cerebral palsy has the advantages of simple surgical method, no special materials and equipment, reliable deformity correction effect, and obvious improvement in function, which effectively improves the patient's self-care ability.

2. Treatment method: The operation is performed under brachial plexus anesthesia, and the tourniquet of the balloon is put on.

2.1 Pronator round muscle cut

Make a longitudinal incision in the middle and lower 1/3 anterolateral side of the forearm, from the muscle space to the medial and lower radial side of the radius, cut off the pronator circular tendon and allow it to retract. Do not damage the periosteum of the radius when cutting the tendon. Layers are stitched in layers.

2.2 Anterior circumflex muscle cut

A longitudinal incision is made above the transverse band of the forearm palm ulnar side from the flexor muscle to the anterior rotator muscle between the ulnar and radial bones. The muscle was cut transversely, and the forearm was rotated to show that there was no obstacle after passive rotation.

2.3 ulnar carpi flexor muscle displacement

Find the ulnar carpi flexor tendon in the same incision that cuts the anterior rotator muscle, cut it from its dead point, and free it about 6 cm in the direction of the muscle abdomen, wrapped in saline gauze for use. Make a longitudinal dorsal incision of the distal radius to find the long abductor tendon. Use a mid-curve hemostatic forceps to make an oblique tunnel subcutaneously from this incision, draw out the ulnar carpi flexor muscle, and use suture suture to intermittently sew it with the abductor hallucis longus tendon so that the thumb is in the abducted and extended position and suture each layer separately Floor.

2.4 The long-arm gypsum tray was U shaped to fix the affected limb in the elbow flexion and supine position. The gypsum was used for functional exercise 6 weeks after the operation.

3. Most patients have improved their postoperative life.