Head Of Flexor Pollicis Brevis Research Articles

Carpal Arch Changes in Response to Thenar Muscle Loading.

This study investigated the biomechanical effects of thenar muscles (abductor pollicis brevis (APB), superficial head of flexor pollicis brevis (sFPB), opponens pollicis (OPP)) on the transverse carpal ligament formed carpal arch under force application by individual or combined muscles (APB, sFPB, OPP, APB-sFPB, sFPB-OPP, APB-OPP, and APB-sFPB-OPP). In ten cadaveric hands, thenar muscles were loaded under 15% of their respective maximal force capacity, and ultrasound images of the cross section of the distal carpal tunnel were collected for morphometric analyses of the carpal arch. The carpal arch height and area were significantly dependent on the loading condition (p < 0.01), muscle combination (p < 0.05), and their interaction (p < 0.01). The changes to arch height and area were significantly dependent on the muscle combinations (p = 0.001 and p < 0.001, respectively). The arch height and area increased under the loading combinations of APB, OPP, APB-sFPB, APB-OPP, or APB-sFPB-OPP (p < 0.05), but not under the combinations of sFPB (p = 0.893) or sFPB-OPP (p = 0.338). The carpal arch change under the APB-sFPB-OPP or APB-OPP loading was greater than that under the loading of APB-sFPB (p < 0.001). This study demonstrated that thenar muscle forces exert biomechanical effects on the transverse carpal ligament to increase carpal arch height and area, and these increases were different for individual muscles and their combinations.

Anastomosis Between the Deep Branch of Ulnar Nerve and a Branch of the Median Nerve (Cannieu-Riché Anastomosis) and Thenar Muscles Innervation. Anatomical Study and Clinical Implications

The aim of this paper was to report the incidences of the anastomosis between deep branch of ulnar nerve and a branch of the median nerve commonly named Cannieu-Riché anastomosis (CRA) and thenar muscles innervation. The anatomical dissection of 80 limbs from 40 fresh adult cadavers were performed in the Department of Anatomy at the Medical School of the Catholic University of São Paulo. The incidence of CRA and thenar muscle innervation were studied. The CRA was found in all of the dissected hands (100 %). The abdutor pollicis brevis and the opponens pollicis muscle are innervated exclusively by median nerve in all dissected hands. The superficial head of flexor pollicis brevis was innervated by the median nerve in of 56 the hands (70 %), in 24 (30 %) it had double innervation (median nerve and deep branch of ulnar nerve). The deep head of flexor pollicis brevis were absent in 11 hands (14 %), in 52 hands (65 %), a double innervation was observed. In 14 (17.5 %) exclusively by deep branch of ulnar nerve and in 3 hands (3.6 %) exclusively by a branch of median nerve. The oblique head of adductor pollicis muscle was innervated only by deep branch of ulnar nerve in 66 hands (82 %) of dissected hands, 14 (17.5 %) had a double innervation. The transverse head of adductor pollicis was innervated exclusively by deep branch of ulnar nerve in 77 hands (96.4 %), and in 3 (3.6 %) had a double innervation. According to our study the pattern of innervation was more frequent in relation to the flexor pollicis brevis muscle and should be considered as a normal pattern, in that the superficial head receives innervation of branches of median nerve, and the deep head receives innervation of deep branch of ulnar nerve and branches of median nerve (dual innervation). The abductor pollicis brevis and opponens pollicis received innervation exclusively by median nerve. Both the oblique and transverse head of adductor pollicis exclusively by ulnar nerve. The RCA was found in all of the dissected hands (100 %).

Phylogeny of the distal musculature of the pectoral appendage

AbstractThe musculature of forearm and manus basically is divisible into dorsal matrix and ventral matrix of elbow, and dorsal matrix and ventral matrix of the podium. The former contributes to the present musculature of brachium and antibrachium, and the latter to the musculature of antibrachium and podium. The forearm muscles of the former category are divisible into humero‐radial (carpi radialis), humero‐podial (digitorum communis et sublimis), and humero‐ulnar (carpi ulnaris) components. The deep muscles of the forearm (mm. abductor pollicis longus, extensor pollicis longus, extensor indicis proprius; flexores digitorum profundus et pollicis longus) have been derived from podial matrices that have migrated proximally along the ulna. The short flexors of the hand have been derived from a superficial and a deep basic series: From the former have come mm. palmaris brevis, abductor pollicis brevis, superficial head of the flexor pollicis brevis, abductor et flexor digiti 5, and lumbricales. From the deep series have been derived mm. contrahentes (including adductor pollicis), interossei, opponens pollicis, deep head of flexor pollicis brevis, and opponens digiti 5.