Neuromuscular Electrical Stimulation for Shoulder Rehabilitation in People with Stroke, a Systematic Literature Review of Randomised Controlled Studies.

The primary aim of this SLR was to establish the most effective parameters for the application of NMES (electrode position, frequency, pulse width, on: off ratio, intensity and dosage) administered for shoulder rehabilitation in people with stroke (PwS). Given the association between GHS and other impairments, the secondary aim was to explore commonly used outcome measures in NMES research for shoulder rehabilitation in PwS.

A systematic literature search was conducted using the electronic databases CINAHL, MEDLINE, and AMED, accessed through EBSCO, the Cochrane Library and Scopus from the date of their inception to March 2024. A search string was constructed combining the key terms  (Electrical stimulation, shoulder, stroke, rehabilitation). We considered randomised controlled trials that used NMES to treat shoulder pain, subluxation, or function in adults. Two researchers independently screened the articles, extracted data, and assessed methodological quality using the PEDro Scale, with a 3rd researcher to settle disputes.

This review, of eight studies (471 participants, with an average age of 57± 6 years), indicates that the application of NMES at a frequency of 10-36 Hz and pulse width of 200-300 μs, over 4 to 8 weeks is associated with reduced shoulder subluxation in PwS. The effective NMES parameters for reducing pain and improving function of the shoulder complex in PwS remain unclear. The most used outcome measures were the Visual Analogue Scale and Numerical Rating Scale, anterior posterior radiography, Fugl-Meyer Assessment and Action Research Arm Test.  

This review has found a high heterogeneity of parameters and outcome measures. To advance the field, future research should prioritise rigorous blinding and standardised dependent variables, outcome measures and reporting of parameters to be able to establish the most effective parameters conclusively.  

• The application of NMES at a frequency of 10-36 Hz and pulse width of 200-300 μs, over 4 to 8 weeks is associated with reduced shoulder subluxation in people with stroke.
• The effective NMES parameters for reducing pain and improving function of the shoulder remains unclear. 
• The most used outcome measures were the Visual Analogue Scale and Numerical Rating Scale for pain, anterior posterior radiography for subluxation and Fugl-Meyer Assessment and Action Research Arm Test for upper limb function.