Date of Award
Master of Science (MS)
People with stroke pedal asymmetrically. There may be differences in their pedaling kinetics between their non-paretic and paretic lower limbs and compared to healthy age matched controls. Previous studies have measured pedaling related impairments and impairments with interlimb coordination using electromyography (EMG). These studies did not use torque as a measurement for pedaling related impairments and interlimb coordination impairments. Pedaling symmetry in the laboratory measuring the torque and work production will fill the gaps of the knowledge about motor compensation during lower limb pedaling. As well, pedaling symmetry has not been measured during fMRI because of the inability to measure torque during fMRI pedaling. The purpose of this study was to redesign a torque measurement device used for pedaling safely in an MR environment and measure impairments of the paretic limb during pedaling and impaired interlimb symmetry. To achieve this purpose, a torque measurement system was redesigned for accurate and precise torque measurements. Participants were asked to pedal on a novel pedaling device, at low loads (work < 40 J), outfitted with the torque measurement system in both the laboratory and an MRI. During either session, there were no differences in pedaling symmetry between groups. The stroke group showed significantly more negative work with greater minimum torque in their paretic limb during both sessions. Similar symmetry measurements between groups suggest that at low loads there is not enough resistance or too low of a work load to exacerbate the asymmetries in pedaling. However, the increased negative work and greater minimum work in the paretic limb suggest that the strategy the stroke group uses for their paretic limb is different than that of their non-paretic limb or controls. Stroke group positive work was correlated with the Fugl Meyer and the symmetry was correlated with Fugl Meyer. These data suggest that the Fugl Meyer may be a predictor of higher positive work and a symmetry index close to 0. Overall, this study describes the design of a torque measuring device that can be used in an MR environment and provides insight into the impaired interlimb symmetry and pedaling dynamics after stroke.