Upper Extremity: Forearm Flashcards
Forearm
- Elbow to wrist
- Radius and ulna
- Connected by interosseous membrane
- Divided into compartments by deep fascia and interossesous membrane
- Muscles primarily are involved in wrist and finger movement (also elbow)
Interosseous Membrane of Forearm
- Syndesmosis: fibrous joint that permits some movement
- Separates compartments
- Muscle attachment
Syndesmosis
- Fibrous joint that permits some movement
Proximal Joints of Forearm (Elbow Joint)
- Humeroradial
- Humeroulnar
- Proximal radioulnar
Distal Joints of Forearm
- Distal radioulnar
- Radiocarpal
Anterior Forearm Functions
- Flexors and pronators
Anterior Forearm Innervation
- Median nerve
- 1 ½ by ulnar
Anterior Forearm Muscle Origination
- Medial epicondyle
- Anterior surface of radius, ulna, interosseous membrane
Posterior Forearm Functions
- Extensors and supinators
Posterior Forearm Innervation
- Radial nerve or one of its branches
Posterior Forearm Muscle Origination
- Lateral epicondyle
- Supracondylar ridge
- Posterior surface of radius, ulna, interosseous membrane
Anterior Compartment Muscles
- 8 muscles
- Some have multiple “heads”
- 3 layers
Superficial (1st) Layer Muscles of Anterior Compartment
- Pronator teres
- Flexor carpi radialis
- Palmaris longus
- Flexor carpi ulnaris
Intermediate (2nd) Layer Muscle of Anterior Compartment
- Flexor digitorum superficialis
Deep (3rd) Layer Muscles of Anterior Compartment
- Flexor digitorum profundus
- Flexor pollicis longus
- Pronator quadratus
Superficial Layer Muscles Proximal Attachment
- All have proximal attachment to medial epicondyle via common flexor tendon
Flexor Carpi Ulnaris and Pronator Teres
- Both have 2 heads
Superficial Layer Muscle Innervation
- All innervated by median nerve
- EXCEPT FCU (innervated by ulnar nerve)
Flexor Carpi Radialis Distal Attachment
- Base of 2nd metacarpal
Flexor Carpi Radialis Function
- Wrist (hand) flexion and abduction
Palmaris Longus Distal Attachment
- Flexor retinaculum and palmar aponeurosis
Palmaris Longus Function
- Tenses palmar aponeurosis (wrist flexion?)
Flexor Carpi Ulnaris Proximal Attachment
- Humeral head: medial epicondyle (via common flexor tendon)
- Ulnar head: olecranon and posterior ulnar border
Flexor Carpi Ulnaris Distal Attachment
- Pisiform
- Hook of hamate
- 5th metacarpal