BMS MSK Asynchronous Lecture 7 STUDENTS.pdf

BMS Anatomy Asynchronous Lecture 7 Muscles of the Anterior Forearm Presented By: Dr. M. Doroudi; [email protected] Boucher Campus) Moore's Clinically Oriented Anatomy, by Arthur F. Dalley II Ph.D. FAAA (Author), Anne M. R. Agur BSc (OT) MSc Ph.D. FAAA (Author), 9th ed. Upper Limb Chapter; Pages: 22...

BMS Anatomy Asynchronous Lecture 7 Muscles of the Anterior Forearm Presented By: Dr. M. Doroudi; [email protected] Boucher Campus) Moore's Clinically Oriented Anatomy, by Arthur F. Dalley II Ph.D. FAAA (Author), Anne M. R. Agur BSc (OT) MSc Ph.D. FAAA (Author), 9th ed. Upper Limb Chapter; Pages: 221 – 227 1 Forearm Compartments Flexor – Pronator Median and/or Ulnar Ns. Extensor - Supinator Radial N. 2 Retinacula 3 Flexor-Pronator Muscles 4 ØPronator Teres (PT); Ori: -Humeral head: Medial epicondyle of humerus (via common flexor tendon) - Ulnar head: Coronoid process of ulna Ins: Middle of the lateral surface of radius Fun: Pronation of the forearm Very weak flex of forearm N:Median (C6,C7) – lateral and medial cords of the brachial plexus Note: Impeachment of median nerve between two heads of PT; pronator syndrome (loss of medial nerve), Twisting rotation of the arm 5 Pulling the radius over the ulna – do not want to fully pronate) Flexion is important to get food to the mouth Pointer finger 5 ØFlexor Carpi Radialis FCR); Ori: Medial epicondyle of humerus (via common flexor tendon) Ins: Base of the 2nd & 3rd. Metacarpals Fun: flex the hand, flex of forearm (weak), abduction (radial deviation) of hand N: Median (C6,C7) – lateral and medial cords of the brachial plexus Note: Radial pulse 6 Middle finger Along side this will be the radial pulse slde 6 ØPalmaris Longus (PL); Ori: Medial epicondyle of humerus (via common flexor tendon) Ins: - Palmar aponeurosis - Flexor retinaculum Fun: flex hand, flex of the forearm (weak) Brachioradialis, between posterior and anterior N: Median (C6,C7) – lateral and medial cords of the brachial plexus Notes: Absent in 12-20% of population 7 At the palm of the hand, covers the tendons in the hand A vestigial muscle 7 ØFlexor Carpi Ulnaris (FCU); Ori: Humeral Head: Medial epicondyle of humerus (via common flexor tendon) Ulnar Head: 1. Olecranon process of ulna 2. Posterior border of ulna Ins: 1. Base of the 5th metacarpal 2. Hook of hamate 3. Pisiform Fun: flex the hand, weak flexor of the forearm, ulnar deviation (adduction of the wrist) N: Ulnar (C7, C8) Notes: Only muscle which is innervated by ulnar N. - Course of ulnar N. between its two heads 8 Infront of the ulnar bone This muscle can aggravate and squeeze on the nerve 8 First four Flexors 9 Add a bit of pressure 9 • Intermediate layer, has only one muscle Ø Flexor Digitorum Superficialis (FDS); Ori: Humero-ulnar head: - Medial epicondyle of humerus (via common flexor tendon) - Coronoid process of ulna Radial head: - Proximal of anterior border of radius Ins: - Base of middle phalanges of fingers # 2-5 Fun: 1. Flexion of finger #2-5 @ MCP and PIP joints 2. Flexion of hand 3. Flexion of forearm (weak) N: Median 10 10 FDS Notes • Irritation of the tendon sheath in CT and pressing the median N. 11 11 q Deep layer; Ø Flexor Digitorum Profundus (FDP); Ori: - Proximal anterior & medial surface of ulna - Interosseous membrane Ins: Base of distal phalanges of fingers # 2-5 Fun: 1. Flexion of finger #2-5 @ MCP and PIP joints 2. Flexion of hand (wrist) N: Median, radial ½ of muscle Ulnar, ulnar ½ of muscle Notes: Dual innervation, Role of medial and lateral halves of muscle in flexing the fingers 12 Ø Flexor Pollicis Longus (FPL); Ori: - Anterior surface of the: - Radius - Interosseous membrane Ins: Base of distal phalanx of thumb Fun: 1. Flexion of thumb @ CMC, MCP and IP joints 2. Flexion of hand N: Median Nerve 13 FPL Notes • One of the C. Tunnel muscles 14 14 Ø Pronator Quadratus (PQ); Ori: Anterior surface of distal ¼ of ulna Ins: Anterior surface of distal ¼ of radius Fun: Pronation of forearm N: Median 15 15