Muscles of the Forearm

• Muscles of the Forearm

  some move the hand at the wrist

  some move the fingers + thumb

  few help pronate + supinate the forearm

  most of thse muscles r fleshy proximally + have long tendons distally, almost all of which insert in the hand

  most muscles that move the hand r located in the forearm + operate the fingers via their long tendons

  = makes the hand less bulky + enables it to perform finer movements
• Flexor & Extensor Retinacula

  at the wrists, these tendons r securely anchored by bandlike thickenings of deep fascia = flexor + extensor retinacula

  these wrist bands keep the tendons fom jumping outward when tensed

  crowded together in the wrist + palm, the muscle tendons r surrounded by slippper tendon sheaths that minimises friction as they slide against one another
• Movements of the Wrist Joint & Interphalangeal Joints

  at the wrist joint, the forearm muscles bring about flexion, extension, abduction + adduction of the hand

  at the interphalangeal joints, these muscle just flex + extend the fingers

  other finger movements r brought about by small muscles in the hand itself
• Flexor Compartments


  fascia subdivides the forearm muscles into 2 main compartments:

  anterior + posterior flexors
• Anterior Flexor Compartment


  most flexors in the anterior compartment originate from a common tendon on the humerus

  2 anterior compartment muscles r not flexors but pronators, the pronator teres + pronator quadratus
• Posterior Extensor Compartment


  muscle of the posterior compartment extend the hand + fingers

  one exception is the supinator muscle which helps the biceps brachii muscle supinate the forearm

  most muscles of the posterior compartment arise from a common tendon on the humerus