Multiple Anatomical Variations in a Pair of Cadaveric Feet

Background: The intrinsic muscles of the foot consist of all muscles that originate and attach to the foot itself (as opposed to those that originate in the leg and insert onto the foot). These muscles include the lumbricals, extensor digitorum brevis, and flexor digitorum brevis, among others, which primarily assist with movement of the toes and in stabilizing the arches of the feet. Case report: During a routine dissection of a pair of cadaveric feet and legs, several variants in the intrinsic musculature of the foot were noted. Bilaterally, there was an absence of the 4th lumbrical and the 4th muscle belly of the flexor digitorum brevis. Also found, were bilateral accessory tendons of the extensor digitorum brevis. While variations of all of these muscles are reported in the literature, there are few descriptions describing bilaterality of the variants described in this specimen. For example, multiple publications describe the absence of at least one lumbrical of the foot in 1-9% of specimens, but only three descriptions of bilateral absence were found on literature review. Discussion: The intrinsic muscles of the foot play an important role in the biomechanics of gait. In addition, the extensor digitorum brevis muscles are frequently used as flaps to repair defects of the foot and ankle. Knowledge regarding the type and incidence of variations in the anatomy of these muscles, therefore, caries true clinical significance and would likely benefit from further research in both cadaveric specimens and living human subjects.