Short and long-term effects of robot-assisted therapy on upper limb motor function and activity of daily living in patients post-stroke: a meta-analysis of randomized controlled trials

Abstract

Objective: To investigate the effect of robot-assisted therapy (RAT) on upper limb motor control and activity function in poststroke patients compared with that of non-robotic therapy.

Methods: We searched PubMed, EMBASE, Cochrane Library, Google Scholar and Scopus. Randomized controlled trials published from 2010 to nowadays comparing the effect of RAT and control treatment on upper limb function of poststroke patients aged 18 or older were included. Researchers extracted all relevant data from the included studies, assessed the heterogeneity with inconsistency statistics (I² statistics), evaluated the risk of bias of individual studies and performed data analysis.

Result: Forty-six studies were included. Meta-analysis showed that the outcome of the Fugl-Meyer Upper Extremity assessment (FM-UE) (SMD = 0.20, P = 0.001) and activity function post intervention was significantly higher (SMD = 0.32, P < 0.001) in the RAT group than in the control group. Differences in outcomes of the FM-UE and activity function between the RAT group and control group were observed at the end of treatment and were not found at the follow-up. Additionally, the outcomes of the FM-UE (SMD = 0.15, P = 0.005) and activity function (SMD = 0.32, P = 0.002) were significantly different between the RAT and control groups only with a total training time of more than 15 h. Moreover, the differences in outcomes of FM-UE and activity post intervention were not significant when the arm robots were applied to patients with severe impairments (FM-UE: SMD = 0.14, P = 0.08; activity: SMD = 0.21, P = 0.06) or when patients were provided with patient-passive training (FM-UE: SMD = - 0.09, P = 0.85; activity: SMD = 0.70, P = 0.16).

Conclusion: RAT has the significant immediate benefits for motor control and activity function of hemiparetic upper limb in patients after stroke compared with controls, but there is no evidence to support its long-term additional benefits. The superiority of RAT in improving motor control and activity function is limited by the amount of training time and the patients' active participation.

Keywords: Meta-analysis; Rehabilitation; Robot-assisted therapy; Stroke; Upper limb.

Fig. 1

A subgroup analysis of the effect of RAT with different total training time versus non-robotic therapy on outcome of FM-UE at the end-of-treatment. The subgroup analysis showed that RAT better improved the outcomes of FM-UE at the end-of-treatment than controls when the total training time was more than 15 h (SMD = 0.15, 95% CI 0.05 to 0.25, P = 0.005), and had no significant clinical benefit with the total training time ≤ 15 h (SMD = 0.26, 95% CI − 0.02 to 0.55, P = 0.07)

Fig. 2

A subgroup analysis of the effect of RAT with different total training time versus non-robotic therapy on outcome of ADL at the end-of-treatment. The subgroup analysis indicated that RAT better improved the outcomes of ADL at the end-of-treatment than controls with the total training time more than 15 h (SMD = 0.32, 95% CI 0.12 to 0.53, P = 0.002), and had no additional benefit with the total training time ≤ 15 h (SMD = 0.25, 95% CI − 0.00 to 0.51, P = 0.05)

Fig. 3

Comparison of the effect of RAT and non-robotic therapy on outcome of ADL at the end-of-treatment in patients with different level of impairment. The subgroup analysis showed that RAT significantly better improved the activity function in patients with mild to moderate paralysis (SMD = 0.27, 95% CI 0.07 to 0.48, P = 0.009), but had the same clinical effect as controls in patients with severe paralysis (SMD = 0.21, 95% CI − 0.01 to 0.42, P = 0.06)

Fig. 4

A subgroup analysis for the effect of RAT versus non-robotic therapy on outcome of FM-UE at the end-of-treatment in different training modes. The result indicated that RAT had better therapeutic effect on motor control function than controls when arm robots provide passive-active (SMD = 0.33, 95% CI 0.06 to 0.59, P = 0.01) and patient-active training (SMD = 0.17, 95% CI 0.03 to 0.31, P = 0.02)

Fig. 5

A subgroup analysis of the effect of RAT versus non-robotic therapy on outcome of ADL at the end-of-treatment in different training modes. The meta-analysis suggested that RAT could better improve the activity function than controls when arm robot provide passive-active (SMD = 0.42, 95% CI 0.15 to 0.68, P = 0.002) and patient-active training (SMD = 0.22, 95% CI 0.03 to 0.40, P = 0.02)