Throughout the imaging field, there are currently no widely accepted standardized behavioral tasks for subjects to execute during fMRI studies. Currently used tasks include finger tapping at frequencies set by a metronome, button presses, and small controlled motions. Unfortunately these tasks do not provide for well controlled studies, as it is often hard to ‘normalize’ the task across subjects. Force monitoring, however, can be generalized across subjects by having subjects target match to a percentage of their maximum effort. This is extremely important when comparing neural plasticity across individuals, such as during the evaluation of therapeutic paradigms. Since supraspinal activation is highly dependent on sensory-motor task, having a controlled environment which can be generalized across subjects is paramount.

Unfortunately there are currently no commercially available force measuring systems which can uniquely quantify forces exerted at the subject’s hand as well as the joint moments being exerted at the wrist. Having a system that can monitor all of these behaviors in real-time can be used during target-matching tasks, where forces or joint moments exerted along particular axes can be displayed to the individual. This allows for well controlled tasks, which in turn can be generalized across subjects.

The purpose of this study is to test a fMRI compatible wrist module we developed which can measure isometric forces and moments developed at the wrist. We are exploring the use of this device during the recovery phases following stroke.
 

Example fMRI scan during wrist flexion-extension exertions