Forearm

Forearm

1. Anterior compartment (flexor-- pronator)

   • Superficial muscles
     • Pronator Teres
       • Pronates and flexes forearms at elbow
     • Flexor Carpi Radialis
       • flexes and abducts hand at wrist
     • Palmaris longus
       • Flexes hand at wrist and tenses palmar aponeurosis
     • Flexor Carpi Ulnari s
       • Innervated: Radial Nerve (C7,C8)
       • flexes and adducts hand at wrist
     • Innervated: Median Nerve
   • Intermediate Muscle
     • Flexor Digitorum Superficialis
       • Flexes middle phalanges at proximal interphalangeal joints of middle four digits; acting more strongly, it also flexes proximal phalanges at metacarpophalangeal joints
     • Innervated: Median Nerve (C7,C8.,T1)
   • Deep
     • Flexor Pollicis Longus
       • Flexes phalanges of 1st digit (thumb)
     • Flexor Digitorum Profundus
       • Medial part innervated: Ulnar nerve (C8,T1)
         • Flexes distal phalanges 4 and 5 at distal interphalangeal
       • Lateral part: flexes distal phalanges 2& 3 at distal interphalangeal joints
     • Pronator quadratus
       • Pronates forearm
     • Innervated by Anterior interosseous nerve, from median nerve (C8,t1)

2. Posterior compartment ( extension-- supination)

   • Superficial
     • Brachioradialis
       • A flexor
       • weak flexion of forearm; maximal when forearm is in midpronated position
     • Extensor Carpi Radialis Longus
       • Extends and abduct hand at the wrist joint
     • Innervated by Deep Branch of Radial Nerve (C7, C8)
       • Extensor Carpi Radialis Brevis
         • extend and abduct hand at the wrist
       • Extensor digiti
         • extends medial four digits primarily at metacarpophalangeal
       • Extensor digiti minimi
         • extends 5th digit primarily at metacarpophalangeal joint, secondary at interphalangeal joint
       • Extensor carpi ulnari s
         • Extends and adducts the hand at wrist joints
     • Innervated by Radial Nerve
   • Deep
     • Suppinator
       • Deep branch of radial nerve (C7,C8)
       • supinates forearm
     • Extensor Indicis
       • extends 2nd digit (enabling its independent extension): helps extend hand at wrist
     • Abductor pollicis longus
       • Abducts thumb and extends it at carpometacarpal joint
     • Extensor pollicis longus
       • extends proximal phalanx of thumb at metacarpophalangeal joint; extends metacarpophalangeal and carpometacarpal joint
     • Extensor pollicis brevis
       • extends proximal phalanx of thumb at metacarpophalangeal joint; extends carpometacarpal
     • Innervated by Posterior Interosseous nerve (C7,C8) continuation of deep brach of radial nerve