Matching Task Difficulty to Patient Ability During Task Practice Improves Upper Extremity Motor Skill After Stroke: A Proof-of-Concept Study

Objective: To test the feasibility of the Fugl-Meyer Assessment of the Upper Extremity "keyform," derived from Rasch analysis, as a method for systematically planning and progressing rehabilitation.

Design: Feasibility study, single group design.

Setting: University rehabilitation research laboratory.

Participants: Participants (N=10; mean age, 59.70±9.96y; 24.1±30.54mo poststroke) with ischemic or hemorrhagic stroke >3 months prior, voluntarily shoulder flexion ≥30°, and simultaneous elbow extension ≥20°.

Interventions: The keyform method defined initial rehabilitation targets (goals) and progressed the rehabilitation program after every third session. Targets were repetitively practiced within the context of client-selected functional tasks not in isolation.

Main outcome measures: Feasibility was defined by subject's pain or fatigue, upper extremity motor function (Wolf Motor Function Test), and movement patterns (kinematics). Assessments were administered pre- and posttreatment and compared using paired t tests. Task-difficulty and patient-ability measures were calculated using Rasch analysis and compared using paired t tests (P<.05).

Results: Ten participants completed 9 sessions, 200 movement repetitions per session in <2 hours without pain or fatigue. Participants gained upper extremity motor function (Wolf Motor Function Test: pretreatment, 22.23±24.26s; posttreatment, 15.46±22.12s; P=.01), improved shoulder-elbow coordination (index of curvature: pretreatment, 1.30±0.15; posttreatment, 1.21±0.11; P=.01), and exhibited reduced trunk compensatory movement (trunk displacement: pretreatment, 133.97±74.15mm; posttreatment, 108.08±64.73mm; P=.02). Task-difficulty and patient-ability measures were not statistically different throughout the program (person-ability measures of 1.01±0.05, 1.64±0.45, and 2.22±0.65 logits and item-difficulty measures of 0.93±0.37, 1.70±0.20, and 2.06±0.24 logits at the 3 testing time points, respectively; P>.05).

Conclusions: The Fugl-Meyer Assessment of the Upper Extremity keyform is a feasible method to ensure that the difficulty of tasks practiced were well matched to initial and evolving levels of upper extremity motor ability.