Neutralizers

Neutralizers: 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.

For example, gluteus minimus , tensor fascia latae , and anterior adductors (hip internal rotators) neutralize the external rotation force generated by the gluteus maximus during hip extension.

• Synonym: There are no commonly used synonyms for this term.
• Opposite: There are no commonly used antonyms for this term.

For additional information, including a video lecture:

• Lesson 21: Functional Roles of Muscles

Functional Roles of Muscles Glossary Terms:

• Prime Mover
• Agonist
• Synergist
• Antagonist
• Neutralizer
• Fixator
• Stabilizer

Articles listing all of the muscles by functional role for each joint action:

• Kinesiology of the Shoulder and Scapula
• Kinesiology of the Elbow
• Kinesiology of the Trunk
• Kinesiology of the Hip
• Kinesiology of the Knee
• Kinesiology of the Ankle

Examples of Joint Actions, Prime Movers, and Neutralizers

Shoulder (Glenohumeral Joint)

• Flexion
  • Prime Movers: Anterior deltoid, pectoralis major (clavicular head), biceps brachii (long head)
  • Neutralizers: Teres minor and infraspinatus (prevent internal rotation caused by pectoralis major and anterior deltoid)
• Extension
  • Prime Movers: Latissimus dorsi, teres major, posterior deltoid
  • Neutralizers: Posterior deltoid (prevents internal rotation caused by the latissimus dorsi and teres major)
• Horizontal Abduction
  • Prime Movers: Posterior deltoid
  • Neutralizers: Subscapularis (prevent external rotation caused by posterior deltoid)
• Horizontal Adduction
  • Prime Movers: Pectoralis major, anterior deltoid
  • Neutralizers: Posterior deltoid, infraspinatus, and teres minor (prevents internal rotation caused by pectoralis major and anterior deltoid)

Hip

• Flexion
  • Prime Movers: Iliacus, psoas, rectus femoris, sartorius
  • Neutralizers: anterior adductors, tensor fascia lata, and gluteus minums (neutralize the external rotation force of the iliacus and psoas)
• Extension
  • Prime Movers: Gluteus maximus, hamstrings (biceps femoris, semitendinosus, semimembranosus), adductor magnus
  • Neutralizers: anterior adductors, tensor fascia lata, and gluteus minums (neutralize the external rotation force of the gluteus maximus, adductor magnus, and biceps femoris)