Positive effects of robotic exoskeleton training of upper limb reaching movements after stroke

Antonio Frisoli,Ilaria Creatini,Bruno Rossi,Carmelo Chisari,Massimo Bergamasco,Luca Bonfiglio,Maria Carboncini,Caterina Procopio

doi:10.1186/1743-0003-9-36

Abstract

This study, conducted in a group of nine chronic patients with right-side hemiparesis after stroke, investigated the effects of a robotic-assisted rehabilitation training with an upper limb robotic exoskeleton for the restoration of motor function in spatial reaching movements. The robotic assisted rehabilitation training was administered for a period of 6 weeks including reaching and spatial antigravity movements. To assess the carry-over of the observed improvements in movement during training into improved function, a kinesiologic assessment of the effects of the training was performed by means of motion and dynamic electromyographic analysis of reaching movements performed before and after training. The same kinesiologic measurements were performed in a healthy control group of seven volunteers, to determine a benchmark for the experimental observations in the patients’ group. Moreover degree of functional impairment at the enrolment and discharge was measured by clinical evaluation with upper limb Fugl-Meyer Assessment scale (FMA, 0–66 points), Modified Ashworth scale (MA, 0–60 pts) and active ranges of motion. The robot aided training induced, independently by time of stroke, statistical significant improvements of kinesiologic (movement time, smoothness of motion) and clinical (4.6 ± 4.2 increase in FMA, 3.2 ± 2.1 decrease in MA) parameters, as a result of the increased active ranges of motion and improved co-contraction index for shoulder extension/flexion. Kinesiologic parameters correlated significantly with clinical assessment values, and their changes after the training were affected by the direction of motion (inward vs. outward movement) and position of target to be reached (ipsilateral, central and contralateral peripersonal space). These changes can be explained as a result of the motor recovery induced by the robotic training, in terms of regained ability to execute single joint movements and of improved interjoint coordination of elbow and shoulder joints.

Highlights

Impairment of upper limb function is one of the most common sequelae following stroke; in particular arm function is found to be altered in 73% to 88% of first time stroke survivors, and 55% to 75% still experience problems that impair their activities of daily living for up to 3 to 6 months or more [1,2].Impairments limit the patient’s autonomy in daily living and may lead to permanent disability [3]
In this study we have investigated the effects of robot aided training on the recovery of spatial reaching movements, with a focus on point-to-point reaching movements performed in different directions, analysing how muscle imbalance in stroke influences the process of motor recovery in terms of regain of smooth movement, interjoint coordination and agonistic/antagonistic muscle recruitment
The recovery of motor capabilities during the chronic phase of impairment after stroke with a rehabilitation treatment is documented in literature [14,15,35]

Summary

Introduction

Impairment of upper limb function is one of the most common sequelae following stroke; in particular arm function is found to be altered in 73% to 88% of first time stroke survivors (infarctions only), and 55% to 75% still experience problems that impair their activities of daily living for up to 3 to 6 months or more [1,2].Impairments limit the patient’s autonomy in daily living and may lead to permanent disability [3]. Impairment of upper limb function is one of the most common sequelae following stroke; in particular arm function is found to be altered in 73% to 88% of first time stroke survivors (infarctions only), and 55% to 75% still experience problems that impair their activities of daily living for up to 3 to 6 months or more [1,2]. Goal directed movements in hemiplegic patients are characterized by lower movement amplitude, prolonged movement time, segmented trajectories and abnormal pattern of muscle activation. Compensatory motor strategies, characterized by adaptations to muscle imbalance [9], are commonly adopted by stroke patients in attempt to overcome these impairments. Various rehabilitation interventions to improve skill reacquisition have shown promising results in overcoming motor impairment after stroke [10]

Methods

Results

Conclusion