A Qualitative and Quantitative Study of Musculature Within the Antebrachial and Carpal Regions in Felis catus.

Abstract

This study was conducted to describe the anatomical features of the manus (paw) muscles in domestic cats, using five males and five females. It provides the first detailed data on the diameters of the digital sesamoid bones and describes, for the first time, the extensor, flexor, abductor and adductor muscles of the first digit, including the abductor pollicis brevis. The flexor digitorum superficialis gave five extensions to the digits and formed the manica flexoria in all but the first digit. The Mm. interossei dorsales were observed as in humans, with distinct origins and insertions. The extensor digiti I [pollicis] was found to be twice as wide as that of digit II. In most specimens, interflexor branches to digits II-IV merged with the flexor digitorum superficialis tendons at the metacarpophalangeal joint. Each manus contained four lumbrical muscles and five vincula tendinum, the latter composed of fibroelastic fibres and blood vessels. It is suggested that the term ligamenta accessorii be used for the vincula tendinum. The lumbrical muscles attached to the metacarpophalangeal joint and coursed toward the middle phalanx, joining the extensor digitorum communis tendons. Among the first digit muscles, the adductor digiti I [pollicis] was the thicker, while the flexor brevis was thicker than the abductor brevis. Histology confirmed fibrocytes and vessels within the ligg. accessorii. This represents the most detailed study of feline manus muscles to date and is expected to contribute significantly to veterinary anatomy.