Robotic Assessment of Lower Extremity Motor Learning

The study is divided into two phases.

In phase I of the study, we intend to assess the response of individuals to a variety of different mechanical perturbations generated by a robotic system for treadmill-based gait training (Lokomat by Hocoma AG). Such response is quantified as a displacement from the baseline (i.e. gait cycles with no mechanical perturbation) trajectory of motion of the foot during the swing phase of the gait cycle. This portion of the study is expected to allow us to identify mechanical perturbations that are suitable to study motor adaptation.

In phase II of the study, we plan to carry out experiments using the above-mentioned robotic system to assess the magnitude of the motor adaptation to the mechanical perturbations identified in phase I as suitable for the study. The magnitude of the motor adaptation is quantified as the percentage of the deviation from the baseline trajectory of motion of the foot that subjects compensate for when exposed to the perturbation during multiple consecutive gait cycles.

It is worth noticing that the robotic system utilized to generate the mechanical perturbations (i.e. Lokomat by Hocoma AG) is not programmed by the company to generate the mechanical perturbations evaluated in this project. Our research group wrote the programs to generate such perturbations. It is also worth emphasizing that the 510K FDA clearance does not cover the modifications implemented by our research group.

Inclusion criteria

• Males and females, healthy adults age 18-55 years, with normal gait.

Exclusion criteria

• Lower extremity fractures
• Current or previous history of orthopedic injury that would prevent safe use of the robotic system
• Body/femoral length size beyond the limits of robotic system (femur length between 350-470mm)
• Body weight > 135kg (~298 lbs) maximum limit of the body weight support system
• Skin lesions on the lower extremities
• Cardiovascular or pulmonary contraindications
• Motor system or proprioceptive impairments
• Severe cognitive impairments that would prevent the use of the robotic system