Healthy Subjects
Conditions
Keywords
motor adaptation, lower extremity motor learning
Brief summary
The aim of the study is to assess the ability of healthy subjects to generate a motor adaptation in response to a mechanical perturbation generated by a robotic system for treadmill-based gait training (Lokomat by Hocoma AG, a device that received 510K FDA clearance).
Detailed description
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.
Interventions
DEVICERobot-induced perturbations
A robotic system is used to generate mechanical perturbations and study how subjects generate motor adaptations in response to the mechanical perturbations.
Sponsors
Spaulding Rehabilitation Hospital
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Step Length Adaptation | within a trial of the experiment (i.e. a few minutes) | The percentage of the step length change caused by the mechanical perturbation that subjects compensate for |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Step Height Adaptation | within a trial of the experiment (i.e. a few minutes) | The percentage of the step height change caused by the mechanical perturbation that subjects compensate for |
Countries
United States
Participant flow
Recruitment details
Healthy subjects were recruited by posting flyers in public areas and by contacting subjects who had previously expressed interest for volunteering in research studies in our laboratory.
Participants by arm
| Arm | Count |
|---|---|
| Robot-induced Perturbations The subject walks on a treadmill with his/her legs strapped to a robotic system (Lokomat by Hocoma AG) that generates mechanical perturbations aimed to modify the subject's walking pattern.
Robot-induced perturbations: A robotic system is used to generate mechanical perturbations and study how subjects generate motor adaptations in response to the mechanical perturbations. | 15 |
| Total | 15 |
Baseline characteristics
| Characteristic | Robot-induced Perturbations |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 15 Participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 2 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 13 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 15 Participants |
| Region of Enrollment United States | 15 Participants |
| Sex: Female, Male Female | 6 Participants |
| Sex: Female, Male Male | 9 Participants |
| Step Height | 9.7 cm STANDARD_DEVIATION 0.2 |
| Step Length | 25.0 cm STANDARD_DEVIATION 0.3 |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 15 |
| other Total, other adverse events | 0 / 15 |
| serious Total, serious adverse events | 0 / 15 |
Outcome results
Primary
Step Length Adaptation
The percentage of the step length change caused by the mechanical perturbation that subjects compensate for
Time frame: within a trial of the experiment (i.e. a few minutes)
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Robot-induced Perturbations | Step Length Adaptation | 83.6 % of step length compensated for | Standard Error 4.5 |
Secondary
Step Height Adaptation
The percentage of the step height change caused by the mechanical perturbation that subjects compensate for
Time frame: within a trial of the experiment (i.e. a few minutes)
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Robot-induced Perturbations | Step Height Adaptation | 6.1 % step height compensated for | Standard Error 4.1 |