MUSCULAR - radio ulnar - lower limb

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  The forearm in “anatomical position,” with the palm facing forward, is supinated
• Rotation of the palm medially so it faces back- wards, or toward the ground if the elbow is flexed 90 degrees,

  is pronation.
• more superficial and lies near the elbow (pronator teres)
• The pronator muscles lie in the forearm
• deep beneath other forearm muscles distally near the wrist (pronator quadratus)
• teres refers to “round earth”
• quadratus refers to the quadrangular shape of the wrist pronator.
• When the pronators contract, they wrap or pull the radius across the stable ulna, proximally by the pronator teres and distally by the pronator quadratus.
• supinator muscles include the biceps brachii of the arm, which is a powerful supinator with the elbow flexed, but with the forearm straight, the supinator, a muscle of the extensor compartment of the forearm executes supination.
• The ulna is stabilized by its articulation at the elbow with the distal end of the humerus and moves very little.
• muscles pronation and supination of the radio-ulnar joint

  1. supinator
  2. pronator teses
  3. pronator quadratus
  4. biceps brachii
• forearm is divided into two muscle compartments by a con- nective tissue intermuscular septum.
• a superficial layer of muscles arises from the medial epicondyle of the humerus
• deep layer of muscles arises from the bones (radius and ulna) of the forearm or the interosseous membrane connecting these bones.
• Pronator teres


  Pronates forearm and flexes elbow
• Flexor carpi radialis


  Flexes hand at wrist and abducts it
• Palmaris longus


  Flexes hand at wrist and tight- ens palmar aponeurosis
• Flexor carpi ulnaris


  Flexes hand at wrist and adducts it
• Flexor digitorum superficialis


  Flexes middle phalanges of medial four digits; also weakly flexes proximal phalanges, forearm, and wrist
• Flexor digitorum profundus


  Flexes distal phalanges of medial four digits; assists with flexion of wrist
• Flexus pollicis longus


  Flexes phalanges of 1st digit (thumb)
• Pronator quadratus


  Pronates forearm
• forearm is divided into two muscle compartments by a con- nective tissue intermuscular septum.
• posterior compartment contains muscles that primarily extend the wrist and fingers
• posterior compartment, a superficial layer of muscles arises largely from the lateral epicondyle of the humerus, whereas a deep layer of muscles arises from the bones of the forearm
• Brachioradialis


  Flexes forearm at elbow, especially in midpronation
• Extensor carpi radialis longus


  Extends and abducts hand at wrist
• Extensor carpi radialis brevis


  Extends and abducts hand at wrist
• Extensor digitorum


  Extends medial four digits at metacarpophalangeal joints; extends hand at wrist joint
• Extensor digiti minimi


  Extends 5th digit at metacar- pophalangeal and interphalan- geal joints
• Extensor carpi ulnaris


  Extends and adducts hand at wrist
• Supinator


  Supinates forearm
• Abductor pollicis longus


  Abducts thumb and extends it at carpometacarpal joint
• Extensor pollicis brevis


  Extends proximal phalanx of thumb at carpometacarpal joint
• Extensor pollicis longus


  Extends distal phalanx of thumb at metacarpophalan- geal and interphalangeal joints
• Extensor indicis


  Extends second digit and helps extend hand at wrist
• (radius and ulna) or the interosseous membrane connecting these bones
• Extensor carpi ulnaris : also adducts the wrist
• Extensor digiti minimi (“minimi” refers to the little finger)
• Brachioradialis: lumped with the posterior forearm muscles because of its innervation, it actually flexes the forearm at the elbow