- Change in Action Research Arm Test (ARAT) [ Time Frame: pre- and immediately post-stimulation ]
- Change in Finger Fractionation [ Time Frame: pre- and immediately post-stimulation ]
- Change in Modified Ashworth Scale (MAS) [ Time Frame: pre- and immediately post-stimulation ]
- Resting State EEG [ Time Frame: pre- and immediately post-stimulation ]
TENS is performed using a commercially available device (ProStim, Alimed Inc, Dedham, Massachusetts, USA). One pair of 2 x 3.5 inches rectangular electrodes (Vermed ChroniCare TENS Electrodes, Vermed, Buffalo, NY, USA) are placed to simultaneously stimulate both median and ulnar nerves at the wrist, while a second pair of round 2 inch diameter electrodes are used to stimulate the radial nerve on the forearm. Bursts of electrical stimulation at 10 Hz (100 microsecond pulse width duration) are delivered to all nerves simultaneously for 2 hours.
Participants with a history of acquired brain injury and distal upper limb motor impairments will receive a single two-hour session of SES using transcutaneous electrical nerve stimulation. Pre- and post-intervention assessments consist of the Action Research Arm Test (ARAT), finger fractionation, pinch force, and the modified Ashworth scale (MAS), along with resting-state EEG monitoring. We will assess for any association between SES and changes in motor outcome as measured using the ARAT, MAS and finger fractionation. In addition, EEG power analyses will be performed to determine if there are any differences between SES responders vs. non-responders.