Can nerve stimulation improve muscle stiffness in patients with stroke?

This study investigated the effect of transcutaneous (through the skin) electrical nerve stimulation (TENS) in muscle stiffness after a stroke. Researchers suggested that TENS reduces leg stiffness in these patients.

Muscle stiffness after stroke affects the quality of life of patients and their caregivers. Up to 43% of patients who had a stroke have this condition and it is associated with decreased recovery. Stiffness is often treated with physical therapy, medication or surgery. TENS consists of the use of electric current produced by a device to stimulate nerves through the skin.

Prior studies showed that TENS reduces stiffness, whereas others indicate no effect at all. There is also a lack of standard methods for the use of TENS in patients with stroke.

The objective of this study was to investigate the effect of TENS to treat muscle stiffness in patients who had a stroke. The effect of different factors (such as intensity or duration of TENS) was also tested.

This study reviewed 12 other studies where patients received TENS alone or TENS associated with other treatments, such as physical therapy or medication. TENS was also compared to a placebo treatment, both combined with physical therapy. 

TENS along with physical therapy was more effective in reducing stiffness in the legs when compared to placebo TENS. When compared to other physical therapy treatments alone, TENS plus physical therapy reduced muscle stiffness.  

This study concluded that TENS can reduce stiffness in leg muscles when applied for more than 30 minutes over nerve or muscle in patients with stroke.

This study was limited to studies published in the English language. Further studies are needed.