Evolution of upper limb kinematics four years after subacute robot-assisted rehabilitation in stroke patients

ABSTRACT

Purpose: To assess functional status and robot-based kinematic measures four years after subacute robot-assisted rehabilitation in hemiparesis.

Materials and methods: Twenty-two patients with stroke-induced hemiparesis underwent a ≥3-month upper limb combined program of robot-assisted and occupational therapy from two months post-stroke, and received community-based therapy after discharge. Four years later, 19 (86%) participated in this follow-up study. Assessments 2, 5 and 54 months post-stroke included Fugl-Meyer (FM), Modified Frenchay Scale (MFS, at Month 54) and robot-based kinematic measures of targeting tasks in three directions, north, paretic and non-paretic: distance covered, velocity, accuracy (root mean square (RMS) error from straight line) and smoothness (number of velocity peaks; upward changes in accuracy and smoothness represent worsening). Analysis was stratified by FM score at two months: ≥17 (Group 1) or <17 (Group 2). Correlation between impairment (FM) and function (MFS) was explored at 54 months.

Results: FM scores were stable from 5 to 54 months (+1[−2;4], median [1st; 3rd quartiles], ns). Kinematic changes (three directions pooled) were: distance −1[−17;2]% (ns); velocity, −8[−32;28]% (ns); accuracy, +6[−13;98]% (ns); smoothness, +44[−6;126]% (p < 0.05). Group 2 showed decline vs. Group 1 (p < 0.001) in FM (Group 1, +3[1;5], p < 0.01; Group 2, −7[−11;−1], ns) and accuracy (Group 1, −3[−27;38]%, ns; Group 2, +29[17;140]%, p < 0.001). At 54 months, FM and MFS were highly correlated (Pearson's rho = 0.89; p < 0.001).

Conclusions: While impairment appeared stable four years after robot-assisted upper limb training during subacute post-stroke phase, movement kinematics deteriorated despite community-based therapy, especially in more severely impaired patients.

Trial registration: EudraCT 2016-005121-36. Registration: 2016-12-20. Date of enrolment of the first participant to the trial: 2009-11-24.

KEYWORDS:

• Hemiparesis
• robot
• kinematics
• intensity
• Frenchay

Acknowledgments

The authors are grateful to the therapy team at ‘Les Trois Soleils’ Hospital for the excellent work with the patients.

Disclosure statement

No potential conflict of interest was reported by the authors.