Gender Difference in Carpal Tunnel Compliance

Abstract

The purposes of this study were to investigate the mechanical properties of the carpal tunnel and to examine carpal tunnel compliance as it related to gender difference. Twelve male and twelve female subjects without any neuromusculoskeletal disorders in the upper extremities participated in the study. Indentation testing was manually performed on the wrist volar to the transverse carpal ligament. Effective compliance was defined as the slope of the regression analyses of indentation force and displacement data. In the tested indentation force range (2.45-19.60 N), the displacement of females was 1.38 ± 0.25 mm, significantly smaller than that of the males, 1.82 ± 0.30 mm ( p < 0.001). Regression analyses in the force range showed that the effective compliance for females, 0.075 ± 0.012 mm/N, was 26.3% lower than that for males, 0.101 ± 0.018 mm/N (p < 0.005). It was concluded that females have less compliant carpal tunnel than males. The gender difference in carpal tunnel mechanics may predispose females to detrimental compression of the median nerve and carpal tunnel syndrome. 153 J. Musculoskelet. Res. 2005.09:153-159. Downloaded from www.worldscientific.com by NANYANG TECHNOLOGICAL UNIVERSITY on 08/24/15. For personal use only.

Volar/dorsal compressive mechanical behavior of the transverse carpal ligament

“…However, indentation is the most common method of evaluating TCL behavior, so it is an important benchmark. The average TCL stiffness in this work (28.0N/mm–non-muscle attachment and 9.7N/mm–muscle attachment sites) was in the same general range as the TCL stiffness that has been measured by in vivo indentation (9.9N/mm for males and 13.3N/mm for females) (Li, 2005). The slight variation may be a result of the fact that the Li 2005 indentation study included compression of the skin and other presumably softer tissues overlying the TCL (muscle, fat, etc.…”

“…Numerous studies have investigated overall compliance of the carpal tunnel complex (Li, 2005; Tung et al, 2010; Zheng et al, 2006) and the TCL’s role in maintaining carpal bone stability (Garcia-Elias et al, 1989; Guo et al, 2009; Li et al, 2009; Tengrootenhuysen et al, 2009; Xiu et al, 2010). However, only a few studies have isolated the TCL and assessed its intrinsic properties.…”

Pressure–morphology relationship of a released carpal tunnel

“…A factor to consider is the structural mechanics of the carpal tunnel because a relatively rigid carpal tunnel is needed for pressure elevation to occur. 13 Previous studies have examined the compliance of carpal tunnel between males and females 14 or among humans and various animals determining that the human carpal tunnel was the least compliant. 13 Another compliance study examined the influence of carpal tunnel pressure on carpal tunnel morphology and found that as carpal tunnel pressure increased, the carpal tunnel area increased and the cross-sectional shape of the carpal tunnel became rounder.…”

Three-dimensional stiffness of the carpal arch

“…Interestingly, the direction of the maximum principal stiffness is also associated with functional wrist kinematics related to dart throwing motion (Capener, 1956; Fisk, 1981; Garcia-Elias, 2013; Li, 2005; Moritomo et al, 2007; Palmer et al, 1985; Werner et al, 2004). Dart throwing motion refers to the most common wrist motion, from radial-extension to ulnar-flexion, that occurs during various functional tasks of the hand such as swinging a hammer (Capener, 1956; Fisk, 1981; Garcia-Elias, 2013; Li, 2005; Moritomo et al, 2007; Palmer et al, 1985; Werner et al, 2004).…”

“…Dart throwing motion refers to the most common wrist motion, from radial-extension to ulnar-flexion, that occurs during various functional tasks of the hand such as swinging a hammer (Capener, 1956; Fisk, 1981; Garcia-Elias, 2013; Li, 2005; Moritomo et al, 2007; Palmer et al, 1985; Werner et al, 2004). The maximum principal stiffness direction is aligned with the rotational axis of dart throwing motion.…”