BMS MSK Asynchronous Lecure 8 STUDENTS.pptx.pdf

BMS Anatomy Asynchronous Lecture 8 Muscles of the Hand 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: 247 – 255 The H...

BMS Anatomy Asynchronous Lecture 8 Muscles of the Hand 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: 247 – 255 The Hand The hand is composed of three parts: the wrist (Carpus), the hand proper (Metacarpus) and the fingers (Digits). The latter are (from lateral to medial) thumb (L. Polex), index (L. Indicis), middle, ring and little (L. digitus minimus) fingers. ❖ The anterior surface of the hand is called the palm and the posterior surface is called the dorsum of the hand. Since the axis of the hand passes through the third metacarpal bone and middle finger, the ABD and ADD of the fingers are considered relative to the long axis of the middle finger. The long axis of the thumb (first metacarpal bone) has 90° medial rotation to the rest of the fingers; as a result, the movements of the thumb are defined at right angles to the movements of the other fingers of hand. ❖Carpal Arch: has been formed by the carpal bones. It is directed anteriorly and has been changed to a tunnel, the so called Carpal Tunnel, by the attachment of the flexor retinaculum to the sides of it. Nine tendons (FDS, FDP & FPL) and a nerve (median nerve) pass through the tunnel. Carpal Tunnel Intrinsic muscles of the hand 1. Thenar 2. Hypothenar 3. Central All these muscles are innervated either by median and/or ulnar nerves. Palmar aponeurosis 6 Thenar group; ❖ Abductor Pollicis Brevis (APB) Ori: - Flexor retinaculum - Tubercle of scaphoid - Tubercle of trapezium Ins: Lateral side of the base of proximal phalanx of thumb Fun: N: 7 ❖Flexor Pollicis Brevis (FPB) Ori: - Flexor retinaculum - Trapezium Ins: Lateral side of the base of proximal phalanx of thumb. Fun: N: 8 ❖Opponens Pollicis (OP) Ori: - Flexor retinaculum - Trapezium Ins: 1st metacarpal Fun: N: 9 ❑ Hypothenar group; All of the hypothenar muscles are innervated by the ulnar nerve Palmaris brevis (PB); Ori: palmar aponeurosis. Ins: skin of the medial side of the hand. Fun: 10 ❖Abductor Digiti Minimi (ADM) Ori: - Pisiform Ins: Medial side of base of proximal phalanx of little finger Fun: N: 11 ❖ Flexor Digiti Minimi Brevis (FDMB) Ori: - Flexor retinaculum - Hook of hamate Ins: Medial side of the base of proximal phalanx of 5th finger Fun: N: 12 ❖ Opponens Digiti Minimi Ori: - Flexor retinaculum - Hook of hamate Ins: 5th metacarpal bone Fun: N: 13 ❑ Central Group of intrinsic hand muscles ❖Adductor Pollicis (AP) Ori: Oblique head: - Base of 2nd & 3rd metacarpal bones - Capitate Transverse head: - Ant. surface of 3rd metacarpal bone Ins: Both heads: - Medial side of the base of proximal phalanx of thumb Fun: N: 14 ADD. Pollicis Note Most of the bulk of the 1st web is made by it 15 ❑ Central Group of intrinsic hand muscles ❖ Lumbrical Muscles; consists of four small and similar muscles. Ori: Tendon of the Flexor Digitorum Profundus (FDP) of each finger Ins: Dorsal digital expansion of four medial fingers - Lumbrical #1: into the dorsal digital expansion of the index finger (finger #2) - Lumbrical #2: into the dorsal digital expansion of the middle finger (finger #3) - Lumbrical #3: into the dorsal digital expansion of the ring finger (finger #4) - Lumbrical #4: into the dorsal digital expansion of the little finger (finger #5) Fun: N: 16 ❑ Central Group of intrinsic hand muscles ❖ Dorsal Interosseous Muscles Ori: Adjacent sides of metacarpals. Ins: Base of proximal phalanges and dorsal digital expansion of fingers (#2, #3,and #4) Dorsal interosseous #1 to the lateral side of the index finger Dorsal interosseous # 2 to the lateral side of the middle finger Dorsal interosseous # 3 to the medial side of the middle finger Dorsal interosseous # 4 to the medial side of the ring finger Fun: N: 17 ❑ Central Group of intrinsic hand muscles ❖ Palmar Interosseous Muscles Ori: Anterior side of metacarpal of fingers #2, 4, and 5 Palmar interosseous #1: metacarpal #2 Palmar interosseous #2: metacarpal #4 Palmar interosseous #3: metacarpal #5 Ins: Base of proximal phalanges and dorsal digital expansion of fingers (#2, 4,and 5) Palmar interosseous # 1 to the index finger (finger #2) Palmar interosseous # 2 to the lateral ring finger (finger #4) Palmar interosseous # 3 to the little finger (finger #5) Fun: N: 18