Stabilizers (Muscle)

Stabilizers: 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.

• Note: For analysis purposes, It is important to differentiate "stabilizers" from "fixators." Fixators are muscles that act to reduce or prevent movement of joints proximal to the joint in motion. For more information, check out fixators .

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 Stabilizers for Major Joints

Shoulder (Glenohumeral Joint)

• Rotator Cuff Muscles:
  • Supraspinatus
  • Infraspinatus
  • Teres Minor
  • Subscapularis

Hip (Acetabulofemoral Joint)

• Gluteus Medius (Posterior and Anterior Fibers)
• Gluteus Minimus
• Piriformis: assists in dynamic stabilization.
• Deep Hip Rotators:
  • Gemellus Superior/Inferior
  • Obturator Internus/Externus
  • Quadratus Femoris

Ankle (Talocrural and Subtalar Joints)

• Tibialis Posterior
• Flexor Hallucis Longus
• Flexor Digitorum Longus
• Peroneus Longus/Brevis: dynamic lateral stabilization.
• Soleus: provides postural stability.

Neck (Cervical Spine)

• Longus Colli
• Longus Capitis
• Scalenes: contribute to stability during dynamic movement.
• Suboccipital Muscles: control upper cervical stability.