Prevalence Summary for Five Aberrant Muscles of the Hand: A Literature Review and Clinical and Pedagogical Resource

Being aware of muscle anomalies and the prevalence of these anomalies is critically important for surgeons but equally useful for anatomy instructors. The purpose of this study was to perform a literature review and then create a clinical and pedagogical resource that provides descriptions and prevalence values for aberrant muscles and tendons on the hand. Bilateral dissections of a cadaver hand revealed an anomalous extensor medii proprius muscles. Twenty journal articles were chosen from an interdisciplinary database. Molded clay muscles and ribbon tendons were added to hand bone models to create visual representations. Variations of the extensor indicis proprius have a collective prevalence rate of 96.5%. The variations of the extensor digitorum brevis manus have a collective prevalence rate of 4%, the extensor medii proprius 3.7%, extensor indicis et medii communis 1.6%, and the three variations of the extensor pollicis et indicis have the lowest collective prevalence rate of 0.75%.