The morphology of the long accessorius muscle

Abstract

In the dissecting-room of this School during the past winter session we have obtained four examples of the long accessorius muscle. We have thought it advisable t o place these on record as they form a useful summary of the various origins of this muscle, when present, and of its relation to the accessorius muscle of the sole (M. quadratus plantae).Many previous observations on this muscle are to be found, in brief, in the accounts by Le Double (1) and Testut (2). We have, however, endeavored to review the subject afresh, in order to present in concise form the views a t present held regarding the origin of this muscle. Our personal investigations have been carried out on twenty-five cadavera, among which only two revealed the presence of the muscle. We have also dissected the myology of the hindlimb in the following animals: Macacus rhesus, Tatusia peba, Alligator mississipiensis.In this way we hoped to obtain information of assistance in interpreting the muscular arrangement in homo. We do not propose at present to publish the result of these dissections, but simply to extract parts which have direct bearing on the subject under discussion. We would acknowledge our indebtedness to Dr. T. Wingate Todd for placing the material a t our disposal and for assistance throughout the investigation. The specimens of Macacus rhesus were generously presented to the Department by the authorities of the Cleveland Zoological Gardens. 341

An unusual variation of the flexor digitorum accessorius longus muscle—its anatomy and clinical significance

“…The short head usually originates a few centimeters superior to the ankle joint. All studies that specify the origin of the short head describe an origin on the fibula (Wood 1866;Driver and Denison 1914;Peterson et al 1995); again, Nathan et al (1975) did not elaborate on the origin of the FDAL. Two-headed FDAL muscles thus can have both heads on one side or on opposite sides of the leg.…”

“…The innervation of the FDAL described here was not preserved, but it is likely the muscle was innervated by a branch of the tibial nerve, as is the case for all other deep posterior compartment leg muscles and previously reported cases of the FDAL. The innervation of the FDAL has only been described twice (Driver and Denison 1914;Jaijesh et al 2006); in both cases the muscle was innervated by the tibial nerve, although one was a oneheaded muscle and the other was two-headed.…”

“…Some authors have described the FDAL as a remnant of the primitive long accessory flexor in primates that migrated to the sole and became the quadratus plantae in humans (Driver and Denison 1914;Nathan et al 1975;Peterson et al 1995;Jaijesh et al 2006). The cadaver examined in this study supports this hypothesis.…”

“…The remainder of the described variations consists of two-headed muscles with one long head originating just distal to the knee and a short head originating a few centimeters superior to the ankle (Wood 1866;Driver and Denison 1914;Nathan et al 1975;Peterson et al 1995). The variation we describe here, a two-headed FDAL muscle with heads of approximately equal size, is extremely rare and has been described in only one other study (Gümüşalan and Kalaycioglu 2000).…”

Morphological Description of the Flexor Digitorum Accessorius Longus Muscle and its Clinical Significance

“…This muscular anomaly has numerous variables regarding its origin site: tibia, fibula, posterior muscle septum, the leg's fascia profunda, and posterior muscular compartment. There are also variations regarding volume and extension (Turner, 1867;Wood, 1868;Macalister, 1875;Testut, 1884;Driver & Denison, 1914;Lewis;Nathan et al, 1975;Nidecker et al, 1984;Bergman et al, 1988;Erickson et al;Sammarco & Stephens;Buckingham et al;del Sol et al;Gümüs¸alan & Kalayciog˘lu, 2000;Kurtoglu et al;Jaijesh et al 2006;Athavale et al, 2012). This muscle was first described by Meckel (Testut;Hwang & Hill, 2009 Sooriakumaran & Sivananthan;Georgiev et al, 2009).…”