Objective: To validate a protocol assessing upper limb kinematics using a planar robot among stroke patients.
Design: Prospective cohort study.
Subjects: Age-matched healthy subjects (n = 25) and stroke patients (n = 25).
Methods: Various kinematic indices (n = 44) were obtained from 4 tasks performed by subjects with REAplan, a planar end-effector robotic device. The metrological properties of this protocol were studied.
Results: In stroke patients, 43 kinematic indices showed moderate to excellent reliability (intraclass correlation coefficients (ICC) range 0.40-0.95; and minimal detectable changes range 9.9-121.1%). In healthy subjects, 25 kinematic indices showed moderate to excellent reliability (ICC range 0.40-0.91) and 3 indices showed a laterality effect (p < 0.05). Many of these indices (27 of 44) were altered in stroke patients in comparison with healthy subjects (p < 0.05). The Box and Block test (manual dexterity) and Upper Limb Sub-score of the Fugl-Meyer Assessment (motor control) showed moderate to good correlations with, respectively, 13 and 4 indices (r > 0.40). Finally, a principal component analysis allowed the elaboration of a short version of the protocol, reducing the number of indices to 5 (i.e. Amplitude, CVstraightness, Speed Metric, CVjerk metric and CVspeed metric).
Conclusion: This study provides a standardized, valid, reliable and sensitive protocol to quantify upper limb impairments in stroke patients, using a planar robot.