Reducing Assymmetry During Gait Using the TPAD (Tethered Pelvic Assist Device) for Stroke Patients

There are a number of common impairments resulting from stroke that contribute to motor
deficits which affect gait, or walking ability. These manifest as decreased walking speed,
and further, as stroke affects only one side of the body, there are resulting asymmetries in
time, spatial and force parameters during walking. Robotic-based therapies have been used to
increase walking speed and reduce asymmetry in a population of individuals after stroke,
however these therapies have demonstrated results similar to that of non-robotic, or
conventional training. This is possibly due to the control strategies used in robotic
training, which strategies limit participant involvement and reduce learning effect. The
Tethered Pelvic Assist Device (TPAD) is a robotic device that uses motorized tethers attached
to a belt at the user's pelvis to guide the pelvis along a pre-set movement trajectory. These
tethers can be configured in an infinite array of possibilities, and most recently have been
used to facilitate a body weight shift onto the paretic limb in a population of individuals
after stroke. Other robotic devices constrain the limb through the entire movement trajectory
and constrict the participants ability to participate in motor planning and movement
execution. The TPAD promotes weight shifting, but allows an individual to freely move the
limb and to navigate leg movement and foot placement independently, without constraints.
Further, if coupled with overground training to promote transfer of improvements to walking
over ground, this device maybe useful at improving symmetry in individuals after stroke.
OBJECTIVES: The purpose of this study is to evaluate the overall feasibility in terms of
safety, treatment tolerance and adherence as well as preliminarily address how effective this
treatment model using the TPAD and overground training would be to reduce load asymmetry on
the treadmill and promote increased stance symmetry on the paretic limb during overground
gait.PARTICIPANTS: A total of 12 individuals in the chronic (>6 months) stages post stroke
will be recruited from a voluntary stroke research database for participation. DESIGN: A
non-randomized pilot study of feasibility will be used to establish the feasibility and
preliminary efficacy of using the TPAD in combination with overground training to reduce load
force asymmetry in this population. METHODS: Participants will undergo a series of three
assessments within a one-week time frame prior to initiating intervention. Intervention using
the TPAD and overground training will occur during week 2 over 5 consecutive visits
(Mon-Fri). Participants will also complete short walks before and after the intervention with
an instrumented system that records individual walking characteristics. Participants will
return one-week after completing the intervention for a final test of walking and balance.
Each study visit will be approximately 1-1.5 hours in duration, and total participation
should be completed within three weeks. EXPECTED OUTCOMES: We anticipate this training
paradigm will prove feasible and effective in reducing both load and stance asymmetry in a
population of individuals with chronic stroke.