Forearm Supination

Forearm Supination
By Alyssa Bitzel

I. Motion:

Supination is the motion which allows an individual to rotate the palm of their hand towards, face up, towards the ceiling. Anatomically, this is where your radius will rotate onto the stable ulna, until to two bones are parallel with each other.

• Primary muscles: Supinator
• Secondary muscles: Biceps Brachii
• Peripheral Nerve: Deep Radial Nerve
• Nerve Root: contribution from C6, which controls the biceps brachii

II. Mobilizing - Increase Range of Motion:

Normal Range of Motion: 85^O

You can stretch this muscle, through both active and passive means of stretching. Passive can allow all the muscles, which include muscles that may restrict supination, such as Pronator Teres, and Pronator Quadratus, to relax into this position. Below are some stretches used to increase range of motion.

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Do these stretches 3x and hold for 30-60 seconds.

III. Indications for Stretching

Common indications which require stretch of the supinator, generally occur when these muscles are tight. Generally this is due when the radio-ulnar joint is in a state of hypo-mobility for a significant amount of time, such as being locked in a brace or a cast to allow heal of bone or ligaments.¹
Mobilizations at the radio-ulnar joint, and even the radio-heumeral joint, can also, significantly increase range of motion into supination.²

IV. Strengthening:

These are some common exercises that can increase the strength of the supinator muscle. They are best done in 3 sets of 10 repetitions each. They can further be progressed by increase the weight of the hand weight or increasing the band resistance.

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V. Potential Clinical Syndromes or Etiologies

Radial Tunnel Syndrome

The Radial nerve passes along the lateral border of the elbow, through the radial tunnel under the supinator muscles. This location is where the radial nerve can become entrapped. This impingement can cause numbness and tingling of the lateral forearm, the little finger, and half of the ring finger. Rest and ice are the most common non-surgical ways of decreasing symptoms, along with light stretches of the muscles and massage to calm the irritation surrounding the nerve.³

SLAP Tears

A SLAP (Superior Labrum Anterior to Posterior) tear involves the tearing of the labrum from the long head of the biceps. Even though the primary focus of rehabilitation of a SLAP tear is at the shoulder, it is commonly shown that patients also need to focus at the elbow, since the biceps is a two joint muscle. Because the biceps controls elbow flexion and supination, patients tend to lack the last couple degrees of flexion and supination. Joint mobilizations, massage and stretching are key aspects to gaining those last couple degrees.⁴

VII. References:

1. Bade H, Strickling H, Rütt J. [Restriction of movement in the proximal and distal radio-ulnar joints in posttraumatic angulation and torsion of the radius]. Aktuelle Traumatol. 1991;21(6):274-8.
2. http://www.painclinic.org/jointpain-elbow.htm
3. Kaswan S, Deigni O, Tadisina KK, Totten M, Kraemer BA. Radial tunnel syndrome complicated by lateral epicondylitis in a middle-aged female. Eplasty. 2014;14:ic44.
4. Cools AM, Borms D, Cottens S, Himpe M, Meersdom S, Cagnie B. Rehabilitation Exercises for Athletes With Biceps Disorders and SLAP Lesions: A Continuum of Exercises With Increasing Loads on the Biceps. Am J Sports Med. 2014;42(6):1315-1322.

Images:
http://www.fixingyou.net/includes/templates/apple_zen/images/pronation_supination_diagram.jpg