Supinator Muscle Review

Overview

• The supinator muscle is part of the extensor muscle group.
• Key for understanding complex anatomy around the elbow joint.

Anatomy

Attachments

1. Proximal Ulna

   • First area of attachment wraps around the posterior aspect of the proximal radius.
   • Hidden from view; indicated by dashed lines.

2. Distal Humerus

   • Second area of attachment.
   • Both components unite and fibers wrap around the proximal radius, attaching to the anterior surface.

Function

• Involved in the action of supination of the forearm.

Visual Aids

Line Drawing of Right Elbow Joint

• Anterior View: Helps in understanding the muscle's location.

Dissection Photograph

• Orientation:

  • Posterior part of the specimen on the left side of the screen.
  • Anterior part on the right side.
  • Palm facing right below the view.

• Muscle Identification:

  • Flexor group muscles and the brachialis muscle seen anteriorly.
  • Supinator muscle located over to the left, wrapping around the proximal radius.

Key Relationships

• Radial Nerve:
  • Travels down the anterior part of the arm, crosses the elbow joint, and divides into:
    • Superficial Branch: Sensory/cutaneous; runs superficial to the supinator.
    • Deep Branch (Posterior Interosseous Nerve): Dives into the supinator muscle.
  • Covered by other extensor group muscles, specifically the brachioradialis.

Summary

• Understanding the attachments, function, and anatomical relationships of the supinator muscle is crucial for comprehending elbow joint mechanics.