NCTraCS Funding Fuels Research by Three PT Faculty

Physical Therapy faculty members Mike Lewek and Karen McCulloch, as well as Professor and PT Division Director Rick Segal, have received funding from the North Carolina Translational and Clinical Sciences Institute (NCTraCS) to help them pursue research in three different areas.

NCTraCS Funding Fuels Research by Three PT Faculty click to enlarge A PT student demonstrates the treadmill in the UNC Human Movement Science Laboratory.

Lewek’s study, Motor Learning Strategies for the Production of Symmetric Gait, will determine how error‐based learning can generate adaptations in spatiotemporal asymmetry during walking for individuals with and without chronic stroke.

Mike Lewek

Following stroke, the paretic, or weaker leg, may be unable to move in the same way as the non-paretic, or stronger leg.  This difference in movements causes an asymmetrical gait.  To address problems related to spatiotemporal (e.g., stance time, step length) asymmetries, Lewek and his collaborators have designed a novel ‘closed loop’ system for the Human Movement Science Laboratory’s dual-belt treadmill.  The treadmill measures spatiotemporal asymmetry in real‐time and can update each belt independently to either augment or minimize spatiotemporal asymmetry.

Lewek will test individuals with chronic stroke and unimpaired control subjects to understand the short term response to these opposing motor learning theories. He expects that augmenting movement errors during training will enhance adaptation more than minimizing errors during training.

Karen McCulloch

McCulloch’s project, Inertial Sensor Measurement of Military Multi-Task Function: A Pilot Study, emerged from earlier research that had emphasized the need for new methods to evaluate functional abilities in soldiers who have sustained concussion/mild traumatic brain injury (c/mTBI). Collaborators in the Division of Physical Therapy and the Department of Biomedical Engineering at UNC Chapel Hill used small, wireless, portable inertial sensors to collect critical indicators of movement duration, variability, and peak velocity in a sample of 20 volunteers including ROTC military cadets.  Movement parameters were analyzed for reliability in order to select the best measures for inclusion in a proposal that recently received funding from the DOD.

Segal and Co-Principal Investigator Heather Walker, MD, UNC Chapel Hill Department of Physical Medicine and Rehabilitation, received NCTraCs funding for a grant titled Operant conditioning of Tibialis Anterior H-reflexes in Patients Post-stroke.  In North Carolina the age-adjusted stroke rate is 57.4 per 100,000 with North Carolina considered the buckle on the stroke belt.  Problems walking after stroke are very common and often include foot drop, a common manifestation of stroke where the Tibialis Anterior (TA) muscle becomes weak or its antagonist muscles (e.g. Soleus) become hyperactive.

Rick Segal

The mechanisms underlying foot drop vary but it consistently causes stroke victims to use compensatory walking behavior if left untreated.  One of the most common treatments is the use of light weight braces that do not encourage the use of TA during walking and will not produce increased strength over time in TA.  Segal and Walker are gathering preliminary data on the feasibility of using operant conditioning of TA H-reflexes to make them larger (up-train) in patients post-stroke with foot drop.