A Reaching Performance Scale for 2 Wolf Motor Function Test Items

Abstract

Objective: To adapt the Reaching Performance Scale for Stroke (RPSS) for the Wolf Motor Function Test (WMFT) "Lift Can" (Can) and "Hand to Box" (Box) items.

Design: Retrospective analysis of video-recorded WMFT assessment performed by 3 raters on 2 occasions.

Setting: Not applicable.

Participants: Participants (N=29) with mild to moderate upper extremity impairment less than 3 months after stroke.

Interventions: Not applicable.

Main outcome measures: Inter- and intra-rater agreement, concurrent validity of WMFT-RPSS.

Results: Mean ± SD inter-rater Gwet's agreement coefficient (AC₂) was 0.61±0.05 for Can WMFT-RPSS and 0.56 (0.03) for Box. Mean ± SD intra-rater AC₂ for Can was 0.63±0.05 and 0.70±0.04 for Box. WMFT-RPSS Can and Box scores correlated with log mean WMFT time (C, -0.73; B, -0.48), Functional Ability Scale (C, 0.87; B, 0.62), Upper Extremity Fugl-Meyer Motor Score (C, 0.69; B, 0.51), and item movement rate (C, 0.74; B, 0.71) (P<.05 for all). Mean ± SD WMFT-RPSS score across the 29 participants was 12.7±3.5 for Can (max score, 19) and 11.4±3.0 for Box (max score, 16).

Conclusions: WMFT-RPSS demonstrated moderate intra-rater and weak-to-moderate inter-rater agreement for individuals with mild-moderate impairment. For construct validity, Can and Box WMFT-RPSS were significantly correlated with 4 standardized measures. Average WMFT-RPSS scores revealed that some participants may have relied on compensatory movements to complete the task, a revelation not discernable from movement rate alone. The WMFT-RPSS is potentially useful as a valid and reliable tool to examine longitudinal changes in movement quality after stroke.

Trial registration: ClinicalTrials.gov NCT00871715.

Keywords: Psychomotor performance; Rehabilitation; Stroke; Upper extremity.