Dorsal Interossei Muscle Anatomy In human anatomy, the dorsal interossei (DI) are four muscles in the back of the hand that act to abduct (spread) the index, middle, and ring fingers away from the hand’s midline (ray of middle finger) and assist in flexion at the metacarpophalangeal joints and extension at the interphalangeal joints of…
Palmar interossei Muscle Anatomy The palmar interossei muscle or volar interossei (interossei volares in older literature) are three small, unipennate muscles in the hand that lie between the metacarpal bones and are attached to the index, ring, and little fingers. They are smaller than the dorsal interossei of the hand. Origin The palmar interossei origins…
Lumbricals Muscle Anatomy The lumbricals are intrinsic muscles of the hand that flex the metacarpophalangeal joints and extend the interphalangeal joints. They are four, small, worm-like muscles on each hand. These muscles are unusual in that they do not attach to bone. This muscle appears to be rather weak based on its modest cross-sectional area…
Opponens Digiti Minimi Muscle Anatomy Opponens Digiti Minimi is a muscle in the hand. It is of a triangular form and placed immediately beneath the palmaris brevis, abductor digiti minimi, and flexor digiti minimi brevis. It is one of the three hypothenar muscles that control the little finger. Together, they make up the hypothenar eminence,…
Abductor Digiti Minimi Muscle Anatomy Abductor Digiti Minimi is a skeletal muscle situated on the ulnar border of the palm of the hand. It forms the ulnar border of the palm and its spindle-like shape defines the hypothenar eminence of the palm together with the skin, connective tissue, and fat surrounding it. Origin Pisiform bone,…
Palmaris brevis Muscle Anatomy Palmaris Brevis is a thin, quadrilateral muscle, placed beneath the integument of the ulnar side of the hand. It acts to fold the skin of the hypothenar eminence transversally. Origin: It originates from the flexor retinaculum (medial) and palmar aponeurosis. Insertion: It inserts into the skin of palm on medial side….
Adductor Pollicis Muscle Anatomy Adductor Pollicis is a fleshy, flat, triangular, and fan-shaped muscle deep in the thenar compartment beneath the long flexor tendons and the lumbrical muscles at the center of the palm. It is situated in the palm and plays a vital role in the movement of the thumb. The term “pollicis” refers…
Opponens pollicis brevis Muscle Details : The opponens pollicis is a small, triangular muscle in the hand, which functions to oppose the thumb. It is one of the three thenar muscles, lying deep to the abductor pollicis brevis and lateral to the flexor pollicis brevis. Origin : The muscle’s superficial head arises from the distal…
Flexor Pollicis Brevis Muscle Anatomy The flexor pollicis brevis is a muscle in the hand that flexes the thumb. It is one of three thenar muscles. It has both a superficial part and a deep part. There are two heads in the flexor pollicis brevis: superficial and deep. The deep head, though, can vary in…
Abductor Pollicis Brevis Muscle Anatomy The abductor pollicis brevis is a flat, thin muscle located just under the skin. It is a thenar muscle and therefore contributes to the bulk of the palm’s thenar eminence. Origin It originates from the flexor retinaculum of the hand, the tubercle of the scaphoid bone, and additionally sometimes from…
