Learn more about the Supinator Muscle so that you can improve your own fitness, performance and health.
What is the Supinator Muscle?
The Supinator Muscle is a spiral muscle contained in the posterior compartment of the forearm, along with brachioradialis, and the superficial and deep forearm extensors.
The Supinator Muscle curls around the proximal part of radius, connecting it with the ulna. In doing so, the muscle crosses the sagittal axis of forearm.
What is the Function of the Supinator Muscle?
The Supinator Muscle, as its name suggests, it is the prime supinator of the forearm.
What other Muscles are Involved in Supination?
In human anatomy, the supinator is curved around the upper third of the radius.
The following muscles supinate the forearm:
- Pronator teres
- Palmaris longus
- Flexor carpi radialis
- Flexor carpi ulnaris
- Flexor digitorum superficialis
What Exercises involve Supination?
Bicep curls and chin ups are the most famous examples.
With a barbell bicep curl, you perform the movement in a supinated position. If you switch your hands into an overhand grip then you perform a reverse barbell bicep curl in a pronated position.
Another easy way to remember is that chin ups are done with a supinated grip. Pull ups are performed with a pronated grip.
What Muscles do Pronation and Supination?
The main muscles enabling pronation of the upper limb are pronator teres, pronator quadratus, and brachioradialis muscles.
Supination is mainly facilitated by supinator and biceps brachii muscles.
Is Supinator Muscle Superficial or Deep?
The Supinator is a deep muscle.
“There are five muscles in the deep compartment of the posterior forearm – the supinator, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus and extensor indicis.
With the exception of the supinator, these muscles act on the thumb and the index finger.”
How do I strengthen my Supinator Muscles?
Add the following exercises into your training.
Supination with a dumbbell
Sit in a chair holding a 2-pound dumbbell vertically in your hand with your elbow resting on your knee.
Let the weight of the dumbbell help rotate the arm outward, turning the palm up.
Rotate the hand back the other direction until your palm is facing downward.
Repeat 20 times on each side.
Wrist and Elbow Strengthening and Stretching Exercises
Try these exercises from Boston Sports Medicine.
Resisted Wrist Flexion
With tubing wrapped around the hand and the opposite end secured under foot, keep the palm facing up and bend the wrist and hand upward as far as you can. Hold one count and lower slowly 3 counts.
This exercise can also be done with a dumbbell.
Resisted Wrist Extension
With tubing wrapped around the hand and the opposite end secured under foot, keep the palm facing down and bend the wrist and hand upward as far as you can.
This exercise can also be done with a dumbbell.
Resisted Forearm Supination and Pronation
Holding a dumbbell, with the forearm supported on your thigh, slowly turn the palm facing up and then slowly turn the palm facing down. Make sure to hold the elbow still and only move the forearm.
Wrist Flexor Stretch
Hold the arm with the elbow straight and the palm facing up. Grasp the involved hand at the fingers and stretch the wrist backward, until a stretch is felt on the inside of the forearm.
Wrist Extensor Stretch
Hold the arm with the elbow straight and the palm facing down. Push downward on the back of the involved hand until a stretch is felt in the muscles on the outside of the forearm.
Biceps Curl
Stand or sit on a bench or chair. With the palm facing forward and the elbow against your side, raise the weight up toward the shoulder. Keep the elbow firmly against your side and lower the weight back to the starting position.
Supinator Muscle
Now you understand the Supinator Muscle, what it does, how to protect it and how to strengthen it.
Check out these other articles on the Gracilis Muscle and Muscle Spindles to learn more.
Image Sources
- Chin-Up: Unsplash