Kinesiology of the Elbow:
By Dr. Brent Brookbush DPT, PT, MS, CPT, HMS, IMT
From the Course:
Additional Courses
- Lesson 11: Biceps Brachii, Brachialis, Triceps Brachii, Brachioradialis and Coracobrachialis (Introductory Course)
Definitions:
- Prime Mover : The muscle that can produce the most force for a joint action. Generally, this is the muscle that will generate the most force during a joint action when exerting force against an external load.
- Agonist : Muscles that perform a joint action, including the prime mover and synergists. That is, unlike the terms prime mover and synergist, agonist refers to all of the muscles that can perform a joint action.
- Synergist : Synergists are muscles that assist the prime mover in performing a joint action. By definition, all agonists that are not the prime mover are synergists.
- Antagonist : Muscles that oppose the agonists (including the prime mover and synergists) for a given joint action. That is, all of the muscles that can perform the opposing joint action.
- Neutralizer : During a joint action, neutralizers are muscles that oppose the unwanted or ancillary joint motions that result from the force generated by the prime mover and/or synergists.
- Fixator : Fixators are muscles that act to reduce or prevent movement of joints proximal to the joint in motion.
- Stabilizer : The role of a stabilizer is to improve arthrokinematics by maintaining optimal alignment of joint surfaces during joint actions. Most often, these muscles are the most intrinsic muscles of a joint. For example, the muscles of the rotator cuff of the shoulder.
Kinesiology of the Elbow Joint
Elbow Flexion:
- Prime Mover: Brachialis
- Synergists: Biceps brachii, brachioradialis
- Antagonists: Triceps, anconeus
- Neutralizers: Pronator quadratus and pronator teres neutralize supination force created by the biceps brachii. Some rotator cuff activation may be necessary to neutralize the flexion force created by the long head of the biceps on the shoulder joint.
- Stabilizers:
- Lateral - Extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris (via common extensor tendon)
- Medial - Pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris, humeral head of flexor digitorum superficialis (via common flexor tendon
- Fixators: Muscles of the shoulder, scapula, and sternoclavicular joint
Elbow Extension
- Prime Mover: Triceps
- Synergist: Aconeus
- Antagonists: Brachialis, Biceps Brachii, Brachioradialis
- Neutralizers: Some rotator cuff activation may be necessary to neutralize the adduction and extension force created by the long head of the triceps on the shoulder joint.
- Stabilizers:
- Lateral - Extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris (via common extensor tendon)
- Medial - Pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris, humeral head of flexor digitorum superficialis (via common flexor tendon
- Fixators: Muscles of the shoulder, scapula, and sternoclavicular joint
© 2011 Brent Brookbush
Questions, comments, and criticisms are welcomed and encouraged –