View commentaries on this research

This is a plain English summary of an original research article

People who have electromechanical or robot-assisted arm rehabilitation after stroke have better arm function and strength as well as finding it easier to complete activities of daily living. Although moderate, the improvements suggest it may be worth considering these interventions as an adjunct to usual therapy.

Many people have impaired arm function after a stroke and rehabilitation is often required. Robot-assisted arm training uses devices to support therapeutic movements. Feedback, given by the machines, allows the exercises to be tailored to the individual. Use can increase the intensity of therapy and improve motivation.

The evidence for their use so far has not been strong, consisting of many small trials. This updated Cochrane systematic review includes new, higher quality research. It now covers 24 types of electromechanical or robot-assisted devices compared to usual care. The studies did not assess cost-effectiveness, and this needs further consideration.

Why was this study needed?

Each year more than 100,000 people in the UK have a stroke. Strokes occur when the blood supply to part of the brain is cut off. The resulting damage can affect both physical and brain function.

Unfortunately, over two thirds of those leaving hospital will have some form of disability. More than three quarters have weakness in their arms affecting their activities of daily living such as getting dressed. Some people recover quickly, but many need longer term rehabilitation.

The previous 2015 Cochrane review concluded that patients receiving robot or electromechanical training are more likely to improve their activities of daily living and arm function and strength, based on 34 trials. This update included 11 new trials and 459 further participants.

What did this study do?

This updated Cochrane systematic review included 45 randomised controlled trials. The trials compared any robot or electromechanical training with any other rehabilitation, placebo or usual care.

The 1,619 participants were mostly recovering from their first ischaemic stroke. Average age ranged from 21 to 80 across the trials. Though all participants had arm muscle weakness, none had restricted arm movement. Trial size ranged between eight and 127 participants and lasted between two and 12 weeks. Trials were predominantly USA based, with just one from the UK.

There were many differences regarding the device used which does impact upon the reliability of the average results and their relevance to all settings.

What did it find?

  • Robot-assisted and machine-assisted arm training slightly improved activities of daily living in people after stroke (standardised mean difference [SMD] 0.31, 95% confidence interval [CI] 0.09 to 0.52; 24 studies, 957 participants). The control group scored 2.08 Functional Independence Measure (FIM) units, out of a possible 7, while the intervention group had a mean score 0.31 standard deviations higher. The low scores show that both groups were still in need of assistance.
  • There was a small improvement in arm function with robot or machine-assisted training compared with control (SMD 0.32, 95% CI 0.18 to 0.46; 41 studies, 1,452 participants).
  • Robot or machine-assisted training had a moderate impact on muscle strength (SMD 0.46, 95% CI 0.16 to 0.77; 23 studies, 826 participants).
  • Adverse events, such as injuries and pain, were rare and when observed were not related to the intervention itself.

What does current guidance say on this issue?

NICE 2013 guidance recommends that people who have weakness in their body or limbs should undertake resistance exercises or training involving weights. Repetitive task training is also advised, using movements such as grasping and pointing.

More recent stroke guidance from the Royal College of Physicians 2016 does refer to machine-assisted arm training. It says that people should only be offered this or neuromuscular electrical stimulation as an adjunct to conventional therapy in the context of a clinical trial. These recommendations upon the previous Cochrane review.

What are the implications?

This evidence strengthens the case for bolstering post stroke rehabilitation with mechanical devices. Though the studies included here were small, the review sets the scene for a larger three-arm trial currently in progress

The additional practical questions it seeks to clarify for the NHS include the cost and cost-effectiveness of the intervention and whether robot-assisted rehabilitation is better than enhanced upper limb therapy of a similar intensity if there are any specific adverse effects in the use of this type of rehabilitation.

For practice, it will be important to clarify the differences between machines, the optimum duration and intensity, and the cost of a rehabilitation programme.

Citation and Funding

Mehrholz J, Pohl M, Platz T, Kugler J, Elsner B. Electromechanical and robot-assisted arm training for improving activities of daily living, arm function, and arm muscle strength after stroke. Cochrane Database Syst Rev. 2018;(9):CD006876.

Cochrane UK and the Stroke Cochrane Review Group are supported by NIHR infrastructure funding.


NICE. Stroke rehabilitation in adults. CG162, London: National Institute for Health and Care Excellence; 2013.

Rodgers H, Shaw L, Bosomworth H et al. Robot Assisted Training for the Upper Limb after Stroke (RATULS): study protocol for a randomised controlled trial. Trials. 2017. 20;18(1):340.

Royal College of Physicians. National clinical guideline for stroke. 5th edition. London: Intercollegiate Stroke Working Party; 2016.

Produced by the University of Southampton and Bazian on behalf of NIHR through the NIHR Dissemination Centre


  • Share via:
  • Print article


The Functional Independence Measure (FIM) is an 18-item measure of dependency for activities of daily living. There are 13 motor and 5 cognitive items measured on a scale of 1-7. 


Expert commentary

Supplementing normal therapy with robot-assisted arm training programmes appears to improve arm recovery after stroke. These benefits were seen in terms of arm strength and function and in the ability to carry out everyday activities.While these results are encouraging it is important to recognise that they are based on a large number of small clinical trials with varying characteristics and design.The results of a current multicentre NIHR funded trial should provide us with clearer estimates of impact.Peter Langhorne, Professor of Stroke Care, University of GlasgowThe commentator declares no conflicting interests 
Back to top