Robotically Assisted Treadmill Training in Spinal Cord Injury (SCI)

This proposal investigates the hypothesis that progressive aerobic exercise with Lokomat is feasible in people with motor incomplete spinal cord injury, and three months of training will improve cardiovascular fitness and gait functionality when compared to physical therapy controls

Little information is available about the cardiovascular effects of robotically assisted partial weight support treadmill training devices such as Lokomat in chronic incomplete spinal cord injured subjects. Task-oriented aerobic exercise has the potential to improve both neuromuscular function and cardiovascular metabolic fitness in neurological populations. Since spinal cord injured individuals are at an increased risk of developing premature cardiovascular disease, the investigation of robotic-assisted interventions in spinal cord injury (SCI) such as the Lokomat may have important health benefits in both cardiovascular fitness as well as functional mobility. This proposal investigates the hypothesis that progressive aerobic exercise with Lokomat is feasible in motor incomplete SCI, and three months of training will improve cardiovascular fitness and gait functionality when compared to physical therapy controls. We propose a two-phase study to examine the feasibility, reliability and utility of aerobic exercise metabolic testing and training during robotically assisted partial weight support treadmill walking in individuals with chronic motor incomplete spinal cord injury (CMISCI). During the first phase of the study we will manipulate Lokomat training parameters of treadmill speed and percent of partial weight support to assess the effect of these changes on heart rate, perceived exertion, and oxygen consumption in untrained chronic motor incomplete spinal cord injured subjects. Subjects will be asked to maintain cardiovascular or muscular effort during testing and will be monitored in this regard by the force biofeedback system built into the Lokomat. After determining threshold levels for initial cardiovascular response, submaximal and then peak exercise testing will be attempted. These studies will be repeated on a separate day to determine the reliability of the testing results. Thirty-six subjects with varying levels of injury between C4 and L2 and ASIA (American Spinal Injury) Impairment Scales of C and D will be recruited. We anticipate that subjects with greater ASIA motor scores will require either a faster initial treadmill speed or less partial weight support to produce an initial cardiovascular response. It is also anticipated that peak exercise testing using open circuit spirometry with subjects on the Lokomat will be a feasible, reliable and valid measurement. This phase of the study will be aimed at establishing guidelines for determining initial training parameters for use in an aerobic exercise protocol using the Lokomat. The second phase of this pilot study will be a controlled trial of three-month progressive aerobic Lokomat exercise in chronic incomplete spinal cord injured subjects. The aim of this trial will be to determine whether progressive Lokomat training will improve cardiovascular fitness and ambulatory function when compared to matched impairment severity CMISCI subjects receiving the same duration of usual physical therapy care. Thirty-six subjects will be recruited into this phase of the study. Open spirometric evaluation of cardiovascular parameters as outlined in phase one of the proposal will be measured at baseline, 1 months, and 3 months. Initial, six-week and post-study ambulatory function evaluations including the WISCI (Walking Index for Spinal Cord Injury), a timed 10 meter walk, a measured walk over 6 minutes, and a gait analysis will also be determined. It is hypothesized that aerobic Lokomat exercise will improve cardiovascular fitness as determined by an increase in VO2 (oxygen consumption) peak and improve function as determined by timed walks and gait parameters in these subjects. The results of this pilot and development study will provide the necessary information to design larger randomized clinical trials.

Subjects will receive active exercise treatment in the Lokomat device 3 times per week for 3 months. Each session will last approximately 45 minutes.

Patients will participate in a home stretching program for 3 months. They will then be crossed over to an active Lokomat treatment for a subsequent 3 months.

The Lokomat is a robotically assisted partial weight suspension treadmill training device that has the potential to restore leg function in persons with incomplete leg paralysis.

Patients will be instructed by a physical therapist on how to perform a home stretching protocol 3 times per week for 3 months. The stretching will be monitored via telephone by the study coordinator. This will be an active control arm. After 3 months the patients will be crossed over to Lokomat training for an additional 3 months. This training will be the same as given to the individuals originally randomized to the Lokomat treatment intervention.

Peak V02 measurements taken during Lokomat exercise in order to measure cardiovascular fitness. Please note that at times the home stretching group would have a second set of measurements at 3 months - one post the 3 month time interval and one later in the 3rd month if there was some delay in initiating the crossover to Lokomat training. This sometimes occurred if the time it would take to complete all of the required studies (e.g. DXA, other secondary measures) was prolonged because of logistical issues.

Peak oxygen consumption during arm cycle ergometry as a measure of cardiovascular fitness. Please note that at times the home stretching group would have a second set of measurements at 3 months - one post the 3 month time interval and one later in the 3rd month if there was some delay in initiating the crossover to Lokomat training. This sometimes occurred if the time it would take to complete all of the required studies (e.g. DXA, other secondary measures) was prolonged because of logistical issues.

DXA assessment of total body mass. Please note that at times the home stretching group would have a second set of measurements at 3 months - one post the 3 month time interval and one later in the 3rd month if there was some delay in initiating the crossover to Lokomat training. This sometimes occurred if the time it would take to complete all of the required studies (e.g. DXA, other secondary measures) was prolonged because of logistical issues.

An assessment of percent body fat as determined by DXA analysis. Please note that at times the home stretching group would have a second set of measurements at 3 months - one post the 3 month time interval and one later in the 3rd month if there was some delay in initiating the crossover to Lokomat training. This sometimes occurred if the time it would take to complete all of the required studies (e.g. DXA, other secondary measures) was prolonged because of logistical issues.

DXA measurement of total lean muscle mass. Please note that at times the home stretching group would have a second set of measurements at 3 months - one post the 3 month time interval and one later in the 3rd month if there was some delay in initiating the crossover to Lokomat training. This sometimes occurred if the time it would take to complete all of the required studies (e.g. DXA, other secondary measures) was prolonged because of logistical issues.

DXA assessment of bone mineral content. Please note that at times the home stretching group would have a second set of measurements at 3 months - one post the 3 month time interval and one later in the 3rd month if there was some delay in initiating the crossover to Lokomat training. This sometimes occurred if the time it would take to complete all of the required studies (e.g. DXA, other secondary measures) was prolonged because of logistical issues.

A functional capacity test to evaluate walking distance during a 6-minute time frame. This measure was only done on those participants that were able to walk for 6 minutes, which represented 9 in the Lokomat training group out of the 12 total randomized to Lokomat training, and 5 out of the 6 randomized to the home stretching group. Please note that at times the home stretching group would have a second set of measurements at 3 months - one post the 3 month time interval and one later in the 3rd month if there was some delay in initiating the crossover to Lokomat training. This sometimes occurred if the time it would take to complete all of the required studies (e.g. DXA, other secondary measures) was prolonged because of logistical issues.

A functional capacity test to measure speed. This measure was only done on those participants that were able to walk, which represented 9 in the Lokomat training group out of the 12 total randomized to Lokomat training, and 5 out of the 6 who were randomized to home stretching. Note that at times the home stretching group would have a second set of measurements at 3 months - one post the 3 month time interval and one later in the 3rd month if there was some delay in initiating the crossover to Lokomat training. This sometimes occurred if the time it would take to complete all of the required studies (e.g. DXA, other secondary measures) was prolonged because of logistical issues.

The step activity monitor measures the total steps taken by an individual over a 48 hour time frame in the home environment. This measure was only done on those participants that were able to walk in the community and did not use a wheelchair for community mobility, which represented 7 in the Lokomat training group out of the 12 total randomized to Lokomat training and 5 out of 6 of the people randomized to home stretching. Please note that at times the home stretching group would have a second set of measurements at 3 months - one post the 3 month time interval and one later in the 3rd month if there was some delay in initiating the crossover to Lokomat training. This sometimes occurred if the time it would take to complete all of the required studies (e.g. DXA, other secondary measures) was prolonged because of logistical issues.

Inclusion Criteria: Acute onset Spinal Cord Injury or Disease at least 12 months prior to enrollment Age 18 to 80 Level of injury from C4 to L2 ASIA impairment scale either C or D Able to tolerate standing frame for at least 30 minutes Exclusion Criteria: History of unstable angina, recent MI (myocardial infarction), CHF (congestive heart failure) or clinically significant valvular dysfunction History of recent hospitalization (<3 months) for a major medical problem

Gorman PH, Geigle PR, Chen K, York H, Scott W. Reliability and relatedness of peak VO2 assessments during body weight supported treadmill training and arm cycle ergometry in individuals with chronic motor incomplete spinal cord injury. Spinal Cord. 2014 Apr;52(4):287-91. doi: 10.1038/sc.2014.6. Epub 2014 Feb 18.

Gorman PH, Scott W, York H, Theyagaraj M, Price-Miller N, McQuaid J, Eyvazzadeh M, Ivey FM, Macko RF. Robotically assisted treadmill exercise training for improving peak fitness in chronic motor incomplete spinal cord injury: A randomized controlled trial. J Spinal Cord Med. 2016;39(1):32-44. doi: 10.1179/2045772314Y.0000000281. Epub 2014 Dec 18.