Intrinsic Muscles of Hand – Origin, Nerve Supply, Functions Intrinsic Muscles of Hand/ The thenar muscles are three short muscles located at the base of the thumb. The muscle bellies produce a bulge, known as the thenar eminence. They are responsible for the fine movements of the thumb. The median nerve innervates all the thenar muscles. Intrinsic Muscles of Hand Thenar muscles Opponents policies Function: Opposition of the thumb Origin: Flexor retinaculum and tubercle of trapezium Insertion: Lateral aspect of first metacarpal Innervation: Recurrent branch of median nerve (C8, T1) Abductor policies Brevis Function: Abduction of the thumb at the metacarpophalangeal joint Origin: Flexor retinaculum and tubercle of scaphoid Insertion: Lateral aspect of proximal phalanx of first finger Innervation: Recurrent branch of median nerve (C8, T1) Flexor pollicus brevis Function: Flexion of the thumb at the metacarpophalangeal joint Origin: Flexor retinaculum and tubercle of trapezium Insertion: Lateral aspect of proximal phalanx of first finger Innervation: Recurrent branch of median nerve (C8, T1) Adductor Compartment Adductor pollicus Function: Adduction of the thumb Origin: Second, third metacarpal, and capitate Insertion: Proximal phalanx and extensor expansion of 1st finger Innervation: Deep branch of ulnar nerve (C8, T1) Hypothenar Muscles Abductor digiti minimi Function: Abduction of the little finger at the metacarpophalangeal joint Origin: Pisiform Insertion: Medial aspect of proximal phalanx of fifth finger Innervation: Deep branch of ulnar nerve (C8, T1) Flexor digiti minimi brevis Function: Flexion of the little finger at the metacarpophalangeal joint Origin: Flexor retinaculum and hook of hamate Insertion: Medial aspect of proximal phalanx of fifth finger Innervation: Deep branch of ulnar nerve (C8, T1) Opponens digiti minimi Function: Opposition of the little finger Origin: Flexor retinaculum and hook of hamate Insertion: Medial aspect of fifth metacarpal Innervation: Deep branch of ulnar nerve (C8, T1) Short Muscles Lubricants Function: Flexion of the metacarpophalangeal joints with extension of the interphalangeal joints Origin: Arise from tendons of flexor digitorum profundus. First 2 are unipennate, and the third and fourth are bipennate Insertion: Extensor expansions of second, third, fourth, and fifth finger Innervation: Median nerve (C8, T1) for the lateral 2 lumbricals, deep branch of ulnar nerve (C8, T1) for the medial 2 lumbricals Dorsal interossei Function: Abduction of the second, third, and fourth finger away from the axial line Origin: Adjacent metacarpals Insertion: Extensor expansions and proximal phalanges of the second, third, and fourth fingers Innervation: Deep branch of ulnar nerve (C8, T1) Palmar interossei Function: Adduction of the second, third, and fourth finger towards the axial line Origin: Palmar surfaces of second, fourth, and fifth metacarpals Insertion: Extensor expansions and proximal phalanges of the second, fourth, and fifth fingers Innervation: Deep branch of ulnar nerve (C8, T1) Surgical Considerations The deltoid is a significant factor when considering the anterior surgical approach to gain access to the shoulder joint. Some of these technical procedures include, but are not limited to the following: Open Bankart repair/capsular reconstructions – indicated in the setting of recurrent anterior (or other directional) instability of the shoulder Shoulder arthroplasty – indicated for cases of post-traumatic deformity, advanced degenerative arthritis, and/or avascular necrosis includes hemiarthroplasty, total shoulder arthroplasty (TSA), reverse total shoulder arthroplasty (TSA) The long head of the biceps tendon (LHBT) – repair versus tenotomy versus tenodesis procedures indicated in the setting of either LHBT/bicipital groove instability or advanced/end-stage LHBT tendinopathy and degeneration[rx][rx] Rotator cuff repair contemporary – indications remain somewhat controversial although most of these procedures are now being performed arthroscopically popular approaches (as opposed to the deltopectoral approach) include the mini-open approach (lateral deltoid-splitting approach) References https://www.ncbi.nlm.nih.gov/books/NBK507892/ https://www.ncbi.nlm.nih.gov/books/NBK525990/ https://www.ncbi.nlm.nih.gov/books/NBK537258/ https://www.ncbi.nlm.nih.gov/books/NBK499858/ https://www.ncbi.nlm.nih.gov/books/NBK545221/ https://www.ncbi.nlm.nih.gov/books/NBK537056/ https://www.ncbi.nlm.nih.gov/books/NBK482410/ https://teachmeanatomy.info/upper-limb/bones/clavicle/ https://www.kenhub.com/en/library/anatomy/the-clavicle Show More