Effects of Robotic Versus Manually-Assisted Locomotor Training for Individuals With Incomplete Spinal Cord Injury (DE)

Effects of Robotic Versus Manually-Assisted Locomotor Training for Individuals With Incomplete Spinal Cord Injury

The purpose of this study is to collect data comparing two means of providing locomotor training: manual and robotic and the possible differential effects it may have on walking ability for persons with spinal cord injury (SCI).

Spinal cord injury (SCI) is one of the most disabling health problems facing adults today, with one of the consequences often being inability to walk or difficulty walking. Recent studies suggest that intensive step training on a treadmill using body-weight support (BWS) and manual assistance that provides repetitive task-specific sensory cues to the neural axis can improve the recovery of walking for persons with incomplete SCI. More recently, robotics have been developed as an alternative to manually-assisted training. Robotic-assisted training may allow for increased intensity of training, improve the reproducibility and consistency of training, and reduce the personnel needed to implement the training. However, the effects of robotic-assisted training compared to manually-assisted training are not known. An improved understanding of these differential effects and the mechanisms of improvement in walking can facilitate continued advances in evidenced-based practice of neuro-rehabilitation, therefore improving the treatment of persons with SCI. The primary objective of this project is to assess and compare the effects of robotic-assisted versus manually-assisted locomotor training (LT) using the body-weight support (BWS) on sub-tasks of walking. Specifically, we believe that at least four sub-tasks of walking are differentially affected by the robotic-assisted training when compared to manually-assisted training (propulsion, transition from stance to step, stepping, and equilibrium). The investigators hypothesize that robotic-assisted training will have a greater effect on improving propulsion, transition and equilibrium. The effect of these two modalities on adaptability, a fifth sub-task of walking, is unclear; therefore, a development component of the pilot project will involve establishing a quantitative measure of adaptability and assessing differential effects of training. Participants will be randomized to one of two training groups: robotic-assisted or manually-assisted, and evaluated for performance on sub-tasks of walking.

Ambulatory Disability, Disability Ambulation, Locomotion Disorders, Motor Activity, Rehabilitation, Spinal Cord Injury

A robotic stepping device in concert with a body weight support system and treadmill is used by a physical therapist and trainers for the participant with spinal cord injury to intensely practice task-specific standing and stepping to advance retraining the capacity to step. The robotic device provides the appropriate kinematics associated with standing and stepping.

A body weight support system and treadmill is used by a physical therapist and trainers for the participant with spinal cord injury to intensely practice task-specific standing and stepping to advance retraining the capacity to step. Therapists and trainers promote the appropriate kinematics associated with standing and stepping.

The total program is 45 sessions, 5x/week with total locomotor training (LT) duration of 30 stepping minutes/day. 1) BWS is initiated at 40% and gradually decreasing to 0%, 2) treadmill speed is set at normal walking speeds and increased as tolerated, and 3) manual assistance given when the subject is unable to independently step or control upright posture, and decreased as participant progresses. Trainers assist via verbal cues and manual assistance to achieve good stepping. The goal for endurance is 20 mins of continuous, independent, coordinated stepping on the treadmill at 0% BWS. Participants are encouraged to assist and/or independently maintain an upright posture, weight shift onto the loaded limb, flex or extend their legs, and to swing their arms in coordination with the legs.

The total program is 45 sessions, 5x/week with total locomotor training (LT) duration of 30 stepping minutes/day. 1) BWS is initiated at 40% and gradually decreasing to 0%, 2) treadmill speed is set at normal walking speeds and increased as tolerated, and 3) manual assistance given when the subject is unable to independently step or control upright posture, and decreased as participant progresses. Trainers assist via verbal cues and manual assistance to achieve good stepping. The goal for endurance is 20 mins of continuous, independent, coordinated stepping on the treadmill at 0% BWS. Participants are encouraged to assist and/or independently maintain an upright posture, weight shift onto the loaded limb, flex or extend their legs, and to swing their arms in coordination with the legs.

Subjects walk on a treadmill with overhead safety mounted to laboratory ceiling while wearing a harness. Treadmill speeds adjusted to lower than overground walking speeds and adjusted to patient reaches a comfortable speed.

Foot angle in a global reference frame at the start of swing phase during treadmill walking at self-selected speed. The kinematic outcomes were first standardized as deviations from control subjects who walk at similar speed (i.e., deviation from the control mean divided by SD among control). Stepping was quantified by the change in orientation of the foot angle (in a global reference frame) from the beginning to the end of the swing phase (i.e., foot-off to foot-down). The values will be identified from the processed 3-D kinematics for each walking cycle and average across steps.

The outcome measure is the percentage of the gait cycle (%) for the occurrence of toe off. Foot trajectory toe-off was identified as indicated in the prior primary outcome (#2). The occurrence of toe-off was then identified relative to the percent of a complete gait cycle and thus the end point of the stance component of the gait cycle and the point of initiation for the swing component of the gait cycle. This outcome is reported in per cent of gait cycle.

Foot trajectory initial contact is the foot angle in a global reference frame at the end of swing (start of stance phase) during treadmill walking at self-selected speed when the foot contacts the ground (i.e. heel strike, foot contact, initial contact). The kinematic outcomes were first standardized as deviations from control subjects who walk at similar speed (i.e. deviation from the control mean divided by the SD among control). Foot trajectory initial contact (heel strike) was quantified by the orientation of the foot angle (in a global reference frame) at foot down (initial contact or heel strike). The values will be identified from the process 3-D kinematics for each walking cycle and averaged across steps. The outcome measurement is in degrees.

Range of foot trajectory from toe off to heel strike in degrees. The kinematic outcomes were first standardized as deviations from control subjects who walk at similar speed (i.e., deviation from the control mean divided by SD among control).

Inclusion Criteria: Adults at least 18 years of age Spinal cord injury (SCO) at least 6 months since injury Motor I-SCI, upper motor neuron lesion only at cervical or thoracic levels A diagnosis of first time SCI including etiology from trauma, vascular, or orthopedic pathology SCI as defined by the American ASIA Impairment Scale categories C or D Medically stable condition that is asymptomatic for bladder infection, decubiti, osteoporosis, cardiopulmonary disease, pain, contractures or other significant medical complications that would prohibit or interfere with testing of walking function and training or alter compliance with the training protocol Documented medical approval from the participant's personal physician verifying the participant's medical status at time of enrollment Ability to walk a minimum of 30 feet with or without an assistive device, independently or with minimal assistance Over ground gait speed < 0.8 m/s Persons using anti-spasticity medication must maintain stable medication dosage during the study Able to give informed consent Exclusion Criteria: Current participation in a rehabilitation program/research protocol that could interfere or influence the outcome measures of the current study History of congenital SCI (e.g. myelomeningocele, intraspinal neoplasm, Friedreich's ataxia) or other degenerative spinal disorders (e.g. spinocerebellar degeneration, syringomyelia) that may complicate the protocol Inappropriate or unsafe fit of the harness or robotic trainer due to the participant's body size and/or joint contractures or severe spasticity that would prohibit the safe provision of either training modality

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