Neurological conditions such as stroke and traumatic brain injury often lead to unilateral
impairments in patients. As a result of the impairment, patients tend not to use their more-affected
side, even though they can use it. This is learned non-use that results from negative reinforcement
early after stroke. In this seminar, a literature review on the phenomenon of learned non-use, the
techniques available to measure it, and the therapeutic methods to counteract learned non-use in
patients with hemiparesis are presented.
The current methods to measure arm use are primarily clinic-based measures and are only a partial
indicator of their actual arm use in daily life. In this seminar, the design and validation of an inertial
measurement unit-based wrist watch like device to track the relative arm use in patients with
hemiparesis are presented. The results from a pilot clinical trial with hemiparetic patients and
healthy controls are also presented.
Learned non-use can be reversed, at least partially, by constraining the less affected limb and
forcing patients to use the more affected limb - constraint-induced movement therapy (CIMT).
However, CIMT is tedious to implement, frustrating for patients, and has poor retention. Recent
studies have shown that arm choice can be altered in the short-term and long-term through subtle
manipulation of rewards during reaching movements in healthy and stroke subjects. An experiment
investigating the effect of CIMT and reinforcement induced movement therapy on healthy subjects
in a visuomotor rotation task was designed and is currently under progress. The experimental
design and preliminary results from this experiment are also presented.