Fingers Joints Abduction and Thumb Flexion PDF 1446 H/2024 A.D Manual Muscle Test

# 1446 H/2024 A.D ## Fingers Joints abduction and Thumb Flexion ### Manual Muscle Test 200PHT-TheoreticalPart_6th Week_ (12th lecture). Jazan University, College of Nursing and Health Sciences, Physical Therapy Department. # 9th lecture Theoretical Part: Fingers Joints Flexion, Extension, and abdu...

# 1446 H/2024 A.D ## Fingers Joints abduction and Thumb Flexion ### Manual Muscle Test 200PHT-TheoreticalPart_6th Week_ (12th lecture). Jazan University, College of Nursing and Health Sciences, Physical Therapy Department. # 9th lecture Theoretical Part: Fingers Joints Flexion, Extension, and abduction ## Objectives: At the end of this lecture the student will be able to: - Know the primary muscles involved in fingers joints abduction and flexion of thumb. - Identify the range of motion of fingers joints abduction and flexion of thumb. - Know the effect of weakness of thumb flexors ## Content: - Anatomy of primary muscles involved in fingers joints abduction and flexion of thumb. - Range of motion of fingers joints abduction and flexion of thumb. - Effect of weakness of thumb flexors. # Finger Abduction Motion ## Primary Muscles: - Interossei dorsales - Abductor digiti quinti ## Range of motion The range of motion of abduction of fingers is of 0° to 20°-25°. ## Anatomy of Interossei dorsales ### Origin From inner aspects of shafts of all metacarpals. ### Insertion Proximal phalanges and dorsal extensor expansion on radial side of index and middle fingers and ulnar side of middle and ring fingers ### Nerve supply Ulnar nerve. ### Action - Abduct fingers away from axis of middle finger - Flex metacarpophalangeal joint while extending interphalangeal joint. ## Anatomy of Abductor digiti quinti. ### Origin Pisiform bone, pisohamate ligament and flexor retinaculum. ### Insertion Ulnar side of base of proximal phalanx of little finger and extensor expansion. ### Nerve supply ulnar nerve. ### Action - Abducts little finger at metacarpophalangeal joint # Flexion of metacarpophalangeal and interphalangeal joints of thumb ## Primary Muscles: - Flexor pollicis longus - Flexor pollicis brevis ## Range of motion: The range of motion of thumb-metacarpophalangeal joint flexion is of 0°to 60°-70° and thumb interphalangeal joint flexion of 0° to 90°. ## Anatomy of Flexor pollicis longus: ### Origin Anterior surface of radius below anterior oblique line and adjacent interosseous membrane. ### Insertion Base of distal phalanx of thumb. ### Nerve supply Median nerve. ### Action Flexes distal phalanx of thumb. ## Anatomy of Flexor pollicis brevis: ### Origin Flexor retinaculum and tubercle of trapezium. ### Insertion Base of proximal phalanx of thumb ### Nerve supply Median nerve. ### Action Flexes metacarpophalangeal joint of thumb ## Effects of weakness: ### Flexor pollicis longus: - Weakness of this muscle decreases the ability to flex the distal phalanx. - Making it difficult to hold a pencil for writing or to pick up objects between the thumb and fingers. ### Flexor pollicis brevis: - Weakness of this muscle decreases the ability to flex the proximal phalanx. - Making it difficult to grip objects between the thumb and fingers. The document also contains several images of a hand, presumably showing the location and actions of the muscles discussed. However, it is not possible to include these images in the markdown format as the task is to convert the document into a structured and readable format, rather than reproduce the original document.