Background: Progressive weakness of the shoulder girdle in FSHD produces gradual decline in upper extremity reachability that ultimately results in impaired Activities of Daily Living (ADLs). Recently, a motion sensor-based assessment system (using Kinect) has been developed that can track upper extremity skeletal motion, and reconstruct an individual’s reachable workspace. Thus far, studies have shown that reachable workspace measure (relative surface area, RSA) has excellent reliability and internal validity as well as sensitivity to detect small changes longitudinally in FSHD. However, determination of whether reachable workspace can also serve as an informative surrogate marker of an individual’s real-life ADL function in FSHD will be important.
Design/Methods: Twenty-one FSHD subjects (13:9 men:women; ages 19-55) with various disease severity as categorized by FSHD clinical severity scale (CSS 1-1.5: 6; CSS 2-2.5: 4; CSS 3-3.5: 6; CSS 4: 5) participated in the study. All subjects underwent Kinect reachable workspace evaluation (per published protocol), and completed the 20-item upper extremity function NeuroQoL questionnaire (Neurological Disorders Quality of Life). Spearman correlation analyses were performed between the reachable workspace and NeuroQoL.
Results: Moderately strong correlation was found between total NeuroQoL scores and total RSA (ρ = 0.7609; p = 0.0001), and upper RSA quadrants (ρ = 0.6969; p = 0.004). Detailed investigation of NeuroQoL with RSA identified 5 items (i.e. shirt on/off, use spoon, pull on pants, pick-up clothes) relevant for proximal upper extremity function and demonstrating high correlation with RSA. This subset of NeuroQoL items displayed very strong associations with both total RSA (ρ = 0.8397; p < 0.0001) and upper quadrant RSAs (ρ = 0.8082; p < 0.0001).
Conclusions: Kinect sensor-acquired reachable workspace demonstrates excellent correlation with patient self-reported upper extremity ADL function in FSHD.