Affiliations: [a] Department of Health and Human Performance, University of Houston, Houston, TX, USA | [b] Center for Neuromotor and Biomechanics Research, Houston, TX, USA | [c] Michael E. DeBakey VA Medical Center, Houston, TX, USA
Abstract: BACKGROUND: Researchers are measuring Reachable Workspace Volume
(RWV) to assess the effects of various interventions on impaired upper
extremity function. These measurement protocols have not been validated.
OBJECTIVE: Assess the validity and reliability of two RWV
protocols.
METHODS: Fifteen able-bodied subjects and eight stroke subjects
participated. Two RWV protocols (POLES and PLANES) were completed and
compared with hemi-spheric volume estimations using the average reach in the
Modified Functional Reach Test (MFRT). RWV, based on the movement of a
single hand marker, was calculated using a 3D motion analysis system (Vicon,
Centennial, CO, USA). Intraclass correlation coefficients (ICC) represented
reliability, Pearson's linear correlation coefficient (r) between RWVs and
MFRT represented validity, and p < 0.05 represented significant differences
between the volumes.
RESULTS: For the able-bodied subjects, the POLES protocol had
excellent validity and excellent reliability, the PLANES protocol had good
validity and excellent reliability, and both RWVs were significantly larger
than estimated MFRT volume. In the stroke subjects, both protocols had good
validity, excellent reliability, and RWVs which were significantly smaller
than the estimated MFRT volume.
CONCLUSIONS: Both measurement protocols provided valid and reliable
measures of RWV. MFRT may underestimate RWV in able-bodied subjects, and
overestimate RWV in stroke subjects.
