Reachable workspace in facioscapulohumeral muscular dystrophy (FSHD) by Kinect

Abstract

Introduction: A depth-ranging sensor (Kinect) based upper extremity motion analysis system was applied to determine the spectrum of reachable workspace encountered in facioscapulohumeral muscular dystrophy (FSHD).

Methods: Reachable workspaces were obtained from 22 individuals with FSHD and 24 age- and height-matched healthy controls. To allow comparison, total and quadrant reachable workspace relative surface areas (RSAs) were obtained by normalizing the acquired reachable workspace by each individual's arm length.

Results: Significantly contracted reachable workspace and reduced RSAs were noted for the FSHD cohort compared with controls (0.473 ± 0.188 vs. 0.747 ± 0.082; P < 0.0001). With worsening upper extremity function as categorized by the FSHD evaluation subscale II + III, the upper quadrant RSAs decreased progressively, while the lower quadrant RSAs were relatively preserved. There were no side-to-side differences in reachable workspace based on hand-dominance.

Conclusions: This study demonstrates the feasibility and potential of using an innovative Kinect-based reachable workspace outcome measure in FSHD.

Keywords: FSHD; function; kinect reachable workspace; upper extremity.

© 2014 Wiley Periodicals, Inc.

Figures

Figure 1. Example graphical outputs of Kinect sensor acquired total and quadrant reachable workspace

A healthy control individual’s reachable workspace viewed from different directions is shown, with quadrants designated by different colors and enumerated 1–4 (A). An example graphical output of the reachable workspace for an individual with moderately impaired upper extremity function is shown in (B).

Figure 2. Radar plot showing mean quadrant relative surface area (RSA) by groups

FSHD patients are shown with a blue line, Controls are shown with a red line (plot shown from right side perspective). The asterisk (*) represents significant differences between cohorts (P<0.01).

Figure 3. Radar plot and bar graph showing mean quadrant relative surface area (RSA) for FSHD patients stratified by FSHD evaluation scale II & III combined score

(A) FSHD patients with score of 1 shown with a dark blue line, 2 in red, 3 in green, 4 in purple, and 5 in light blue; plot shown from right side perspective. (B) Bar graph showing the gradual reduction in the total and quadrant RSAs by combined FSHD subscale II & III. (healthy control=0, and combined subscale II & III scores: 1–5).