Changes in Carpal Tunnel Shape During Wrist Joint Motion

Abstract

This study evaluated dynamically the morphology of the carpal tunnel during the wrist motion. The object was to determine the transverse dimension (TD), anteroposterior (AP) dimension and cross-sectional area (CA) of the carpal tunnel in the neutral, flexed and extended positions. The wrists of eight male and eight female volunteers aged 20 to 38 years were studied. With wrist extension, AP and CA decreased while the TD increased at the pisiform level, and CA increased at the hamate level. With flexion, TD and CA decreased at the pisiform level and CA decreased at the hamate level. The results showed that the median nerve may be subjected to significant pressure at the pisiform level when the wrist is extended. During wrist flexion, the cross-sectional area decreased at both the level of the pisiform and the hook of the hamate.

The Development of a New Orthosis (Neuro-Orthosis) for Patients with Carpal Tunnel Syndrome

“…The resulting range of motion was still in the safe region in terms of CTP. 10,[12][13][14]16 NeO was more effective in limiting the movements in the sagittal plane. During the adjustment period, the isolation of extensor carpi radialis longus muscle was generally difficult with surface stimulation.…”

“…[9][10][11] Changes in wrist position lead to alterations in carpal tunnel shape, 12 thereby influencing the CTP. It has been shown that when the wrist is in neutral, the CTP is minimum.…”

Evaluation of the carpal tunnel based on 3-D reconstruction from MRI

“…Compression of the median nerve can result from mechanical impingement or increased hydrostatic pressure, both of which have been shown to occur with deviation from a neutral wrist posture (Smith et al, 1977;Gelberman et al, 1981;Rojviroj et al, 1990;Weiss et al, 1995;Keir et al, 1997;Werner et al, 1997;Luchetti et al, 1998). It has also been demonstrated that the cross-sectional area (CSA) of the carpal tunnel changes with deviation from a neutral wrist posture (Skie et al, 1990;Yoshioka et al, 1993;Allmann et al, 1997;Bower et al, 2006). Changes in carpal tunnel pressure are a function of tunnel volume as well as the volume of its contents.…”

Carpal tunnel syndrome: A review

“…During the wrist flexion and extension the pressure may rise to 90 mmHg (22). Magnetic resonance (MR) h-as shown compression of the MN to take place at the pisiform level with wrist extension, and at the pisiform and at the hook of hamate level with wrist flexion (23). Increased pressure in the CT is not the only factor involved.…”