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Challenge the potential of your strength

U.S. Patent No. 9,089,738

Muscles and Motions

What specifically can The Pronator do for you?

Primary movements

  • Pronation: loosen a screw, flip a pancake, loosen a light bulb
  • Supination: tighten a screw, screw in a light bulb
  • Radial Deviation: throw a frisbee, set a fish hook, unscrew a jar
  • Ulnar Deviation: hammer in a nail, throw a dart, wash dishes
  • Elbow Flexion: carrying a bag of groceries, picking up a child, pulling up your trousers
  • Elbow Extension: pushing open a heavy door, transferring out of a chair, throwing a shot put
  • Shoulder Internal Rotation: closing a door, pouring a gallon of milk, throw a baseball, serve a tennis ball, spike a volleyball
  • Shoulder External Rotation: open a cabinet, majority of kung fu moves, pass a dish, shake a rug
  • -note some of these motions will be reversed for left handed people
The Pronator can improve the strength of many forearm, arm and shoulder muscles

This list does not end here. We all know that the foundation of being a therapist is creativity based on kinesiology. Everyday we are challenged to adapt treatment to a patient's needs, and to think outside the box. The Pronator's potential to enhance your patients' ability to excel at functional tasks is limited only by your imagination.

Principle Motions and Corresponding Muscles1

Have an injured muscle or are in need of strengthening a specific motion?

Look at the charts below to identify the movements The Pronator can help strengthen and the muscles that perform each motion.


Primary muscle activation

Secondary muscles


Pronator quadratus

Flexor carpi radialis

Pronator teres

Palmaris longus

Brachioradialis when arm is supinated



Radial wrist extensors

Extensor pollicis longus

Biceps Brachii

Extensor Indicis

Brachioradialis when arm is pronated

Note: the Supinators as a group are approximately 25% stronger than the Pronator group. This is due to a near-double cross-sectional area of the Supinator group. Keep in mind, when starting to strengthen a client or patient, a weight that is easy turning palm up, may strain the Pronators while turning palm down.1

The Pronator is an ideal device to strengthen the upper extremity.

Examine the list of upper extremity motions below to see how The Pronator can fit your needs.



Radial Deviation

Extensor capri radialis (longus and brevis)

Extensor pollicis (longus and brevis)

Flexor carpi radialis

Abductor pollicis longus

Flexor pollicis longus

Ulnar Deviation

Extensor carpi ulnaris

Flexor carpi ulnaris

Flexor digitorum superficialis

Flexor digitorum profundus

Extensor digitorum

Elbow Flexion

Biceps brachii (long and short head)



Pronator teres

Elbow Extension

Triceps brachii


Shoulder Internal Rotation


Anterior deltoid

Pectoralis major

Latissimus dorsi

Teres major

Shoulder External/Lateral Rotation


Teres minor and posterior deltoid

1Neumann, Donald A. Kinesiology of the Muscloskeletal System: Foundations for Rehabilitation, St Loius: Mosby Inc, 2010