Mobility Skills With Exoskeletal-Assisted Walking in Persons With SCI: Results From a Three Center Randomized Clinical Trial

Abstract

Background: Clinical exoskeletal-assisted walking (EAW) programs for individuals with spinal cord injury (SCI) have been established, but many unknown variables remain. These include addressing staffing needs, determining the number of sessions needed to achieve a successful walking velocity milestone for ambulation, distinguishing potential achievement goals according to level of injury, and deciding the number of sessions participants need to perform in order to meet the Food and Drug Administration (FDA) criteria for personal use prescription in the home and community. The primary aim of this study was to determine the number of sessions necessary to achieve adequate EAW skills and velocity milestones, and the percentage of participants able to achieve these skills by 12 sessions and to determine the skill progression over the course of 36 sessions. Methods: A randomized clinical trial (RCT) was conducted across three sites, in persons with chronic (≥6 months) non-ambulatory SCI. Eligible participants were randomized (within site) to either the EAW arm first (Group 1), three times per week for 36 sessions, striving to be completed in 12 weeks or the usual activity arm (UA) first (Group 2), followed by a crossover to the other arm for both groups. The 10-meter walk test seconds (s) (10MWT), 6-min walk test meters (m) (6MWT), and the Timed-Up-and-Go (s) (TUG) were performed at 12, 24, and 36 sessions. To test walking performance in the exoskeletal devices, nominal velocities and distance milestones were chosen prior to study initiation, and were used for the 10MWT (≤40s), 6MWT (≥80m), and TUG (≤90s). All walking tests were performed with the exoskeletons. Hong et al. Mobility Skills With EAW Results: A total of 50 participants completed 36 sessions of EAW training. At 12 sessions, 31 (62%), 35 (70%), and 36 (72%) participants achieved the 10MWT, 6MWT, and TUG milestones, respectively. By 36 sessions, 40 (80%), 41 (82%), and 42 (84%) achieved the 10MWT, 6MWT, and TUG criteria, respectively. Conclusions: It is feasible to train chronic non-ambulatory individuals with SCI in performance of EAW sufficiently to achieve reasonable mobility skill outcome milestones.

The Effect of Exoskeletal-Assisted Walking on Spinal Cord Injury Bowel Function: Results from a Randomized Trial and Comparison to Other Physical Interventions

“…Participants with motor-complete injury (American Spinal Injury Impairment Scale (AIS) A and B) represented 62% of the participants, and those with motor-incomplete injury (AIS C and D) made up the remaining 38%. More complete demographic data have been previously presented [ 21 ].…”

“…The primary aim of the study was to determine the number of sessions necessary to achieve adequate EAW skills and hypothesized velocity milestones. The mobility component of the study, as well as the detailed eligibility criteria, has been published elsewhere [ 21 ]. Briefly, individuals with paraplegia or tetraplegia greater than six months in duration, between 18 and 65 years old, unable to ambulate faster than 0.17 m/s on level ground, wheelchair dependent for mobility, and without any history of concurrent medical or neurologic disease or history of lower extremity fracture within the past two years were eligible for the study.…”

“…Lofstrand crutches or a walker are required for balance and stability during standing, stepping and walking. Additional information about the exoskeletal training and decision tree for the devices has been published elsewhere [ 21 ].…”

Closed-Loop Torque and Kinematic Control of a Hybrid Lower-Limb Exoskeleton for Treadmill Walking

“…Restoring and improving the ability to walk is a top priority for individuals with paralysis, whose locomotion is affected by muscle weakness, impaired postural stability and reduced leg coordination Anderson (2004) . Robotic exoskeletons assist individuals with paralysis to improve their gait kinematics, cardiorespiratory and metabolic responses, balance, and mobility ( Field-Fote and Roach, 2011 ; Yang et al, 2015 ; Ramanujam et al, 2018 ; Kressler et al, 2018 ; Sale et al, 2018 ; Kressler and Domingo, 2019 ; Hornby et al, 2020 ; Hong et al, 2020 ). However, exoskeletal-assisted walking in isolation faces challenges in improving muscle capacity and reinforcing the activation of paralyzed muscles during locomotion ( Edgerton et al, 2001 ; Field-Fote and Roach, 2011 ).…”

Restoration of Complex Movement in the Paralyzed Upper Limb

“…Current attempts to restore limb function following spinal cord injury (SCI) rests on four main strategies: surgical reconstruction -often involving tendon transfers from non-paralyzed to paralyzed muscle . [1] , repair the injury using a variety of neuroprotective and neuroregenerative agents including cell transplantation [2][3][4][5][6] , artificially enable movement with powered exoskeletons [7][8][9] , or activate paralyzed muscles, either by exciting spinal circuits below the level of the lesion [10][11][12][13][14][15][16][17][18] or by directly stimulating motor axons innervating muscle [19][20][21][22][23][24] . Therapeutic approaches, such as movement training [11,[25][26][27][28] and sustained electrical stimulation spanning (and upstream) of the injury site [30][31][32][33] have also been used effectively to enhance recovery in SCI, presumably by promoting axonal outgrowth [29] and synaptic plasticity [33] .…”