Fixators (Muscle)
Fixators: Fixators are muscles that act to reduce or prevent movement of joints proximal to the joint in motion. For example, the muscles of the core (rectus abdominis , external obliques , internal obliques , quadratus lumborum , erector spinae ) are important fixators, reducing trunk motion during motion of the arms or legs.
- Note: For analysis purposes, it is important to differentiate "fixators" from "stabilizers." A stabilizer improves arthrokinematics by maintaining optimal alignment of joint surfaces during joint actions. For more information, check out stabilizer .
For additional information, including a video lecture:
Functional Roles of Muscles Glossary Terms:
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 Hip Extension Kinesiology Analysis, including Fixators:
Hip Extension
- Prime Mover: Gluteus maximus
- Synergists: Biceps femoris (long head) , semitendinosus, semimembranosus , posterior head of adductor magnus
- Antagonists: Psoas , iliacus , tensor fascia latae (TFL), rectus femoris , anterior adductors (especially pectineus) , sartorius
- Neutralizers: Gluteus minimus and anterior fibers of gluteus medius neutralize external rotation force of gluteus maximus
- Stabilizers: Deep rotators of hip
- Fixators: Intrinsic stabilization subsystem , rectus abdominis , internal and external obliques , quadratus lumborum , erector spinae