Bilateral Priming Plus Task Specific Training for Severe Upper Limb Hemiparesis

"Priming will always precede task specific training. During bilateral motor priming, the Rocker (Exsurgo Bilateral Primer, Aukland, New Zealand) will be used. For the individuals assigned to the bilateral priming group, both hands will be strapped in place in the vertically oriented plates which are attached via a mechanical linkage. They will move both wrists in rhythmic, symmetrical wrist flexion and extension for 15 minutes at a frequency of 1 Hz as cued by a metranome. Subjects do not need to have active flexion and extension of the affected hand as the less affected arm drives the weaker one (through an acutator underneath the surface) in in-phase bilateral symmetrical movement."

The control priming intervention for the active comparator group will be intermittent cutaneous electric stimulation of the volar aspect of the paretic forearm, using a standard TENS unit delivered for 15 seconds (including 2-second ramp-up, 2-second ramp-down), once per minute, for 15 minutes. Intensity will be minimized