The oblique cord of the forearm in man

Abstract

There is minimal and often conflicting data in the literature regarding the oblique cord of the forearm. The current study seeks to elucidate further the anatomy of this structure of the upper extremity. In adult cadavers, the oblique cord was observed for and, when found, measurements were made of it. Ranges of motion were carried out while observation of the oblique cord was made. An oblique cord was found on 52.6% of sides. Gantzer's muscle was found on 55% of sides and, when present, had attachment into the oblique cord on five sides. The oblique cord was present on 13 sides with a Gantzer's muscle. Of the 20 sides with an oblique cord, no Gantzer's muscle was found on 10. The mean length of the oblique cord was 3.4 cm. In the majority of specimens, this cord tapered from proximal to distal. The proximal, middle, and distal widths of this structure had means 9, 7, and 4 mm, respectively. The oblique cord was found to travel approximately 45 degrees from a line drawn through the ulna and more or less traveled perpendicular to the insertion site of the bicipital tendon. This ligament was lax in the neutral position and with pronation became lax in all specimens. The oblique cord progressively became taut with increased supination from the neutral position and was maximally taut with the forearm fully supinated. Tautness of this cord was also found with distal distraction of the radius. Following the transection of the oblique cord, no discernable difference was observed in regard to maximal supination of the forearm or distal distraction of the radius. No obvious instability of the proximal forearm was found following transection of the oblique cord. Functionally, although the oblique cord may resist supination, it is unlikely that this structure affords significant stability to the proximal forearm, as it was often absent, of a very small caliber, and based on our observations, following its transection, the amount of supination of the forearm did not increase. Moreover, one would expect that this structure would never resist supination alone, as the larger overlying muscles would become taut prior to calling upon the action of this cord. Based on our findings, the function of the oblique cord appears insignificant in providing significant stability to the proximal forearm; however, further investigative studies are now necessary to confirm these data.

Interosseous Membrane of the Forearm: Length Change of Ligaments During Forearm Rotation

“…Functions of this ligament are controversial and unconfirmed. Martin 7 and Tubbs et al 8 stated in their respective cadaveric studies that the proximal oblique cord is lax in the neutral position and pronation but taut in supination. Conversely, Patel 9 reported in his study, using forelimbs of anthropoid primates, that the ligament was lax in the neutral position and supination but became taut in pronation.…”

Predictive factors for re-displacement in diaphyseal forearm fractures in children—role of radiographic indices

“…1992, Kapandji 2001, Moore and Dalley 2006, Tubbs et al. 2007). Thus, in the present study, forearm fractures were cast in neutral supination/pronation, contributing to effective immobilization.…”

Interosseous Membrane of the Forearm: An Anatomical Study of Ligament Attachment Locations

“…The proximal oblique cord is a relatively wellinvestigated component, [13][14][15]23 whereas descriptions of this ligament are variable. Some authors 23 have insisted that the structure is a remnant or accessory head of the flexor pollicis longus muscle (Gantzer's muscle), whereas another author 13 has stated that this cord represents a thickening of the fascia overlying the supinator muscle or perhaps even a degenerate part of the supinator muscle.…”

“…Conflicting descriptions of function have been reported. [13][14][15] Martin 13 and Tubbs and colleagues 14 described the cord as being most taut in supination and lax in both the neutral position and pronation in human cadavers, suggesting action as a restraint on excessive supination motions. Conversely, Patel 15 reported that the proximal oblique cord became most taut in pronation rather than in supination in the forelimbs of quadrupedal primates, suggesting a possible role in maintaining elbow stability when such primates stand on their pronated forelimbs.…”