Mechanisms for improving walking speed after longitudinal powered robotic exoskeleton training for individuals with spinal cord injury

Background:People with spinal cord injury walk with a flexed trunk when using reciprocating gait orthoses for walking. Reduction in trunk flexion during ambulation has been shown to improve gait parameters for reciprocating gait orthosis users.Objective:The aim of this study was to investigate the effect on energy expenditure when spinal cord injury patients ambulate with an advanced reciprocating gait orthosis while wearing a thoracolumbosacral orthosis to provide trunk extension.Study design:Quasi experimental study.Methods:Four patients with spinal cord injury were fitted with an advanced reciprocating gait orthosis after completing a specific gait training program. Patients walked along a flat walkway using the advanced reciprocating gait orthosis as a control condition and also while additionally wearing a thoracolumbosacral orthosis at their self-selected walking speed. A stopwatch and a polar heart rate monitor were used to measure walking speed and heart rate.Results:Walking speed, the distance walked, and the physiological cost index all improved when walking with the advanced reciprocating gait orthosis/thoracolumbosacral orthosis test condition compared to walking with no thoracolumbosacral orthosis in situ.Conclusion:Spinal cord injury patients can improve their walking speed, walking distance, and physiological cost index when wearing a thoracolumbosacral orthosis in conjunction with an advanced reciprocating gait orthosis, which may be attributed to the trunk extension provided by the thoracolumbosacral orthosis.Clinical relevanceIt is concluded that wearing thoracolumbosacral orthosis in association with an advanced reciprocating gait orthosis could be an effective alternative in rehabilitation for thoracic level of paraplegic patients to promote their health and well-being.

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Stabilization Strategies for Fast Walking in Challenging Environments With Incomplete Spinal Cord Injury

Frontiers in Rehabilitation Sciences ◽

10.3389/fresc.2021.709420 ◽

2021 ◽

Vol 2 ◽

Author(s):

Tara Cornwell ◽

Jane Woodward ◽

Wendy Ochs ◽

Keith E. Gordon

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Walking Speed ◽

Center Of Mass ◽

Lateral Stability ◽

Step Width ◽

Incomplete Spinal Cord Injury ◽

Foot Placement ◽

Fast Speed ◽

Cord Injury

Gait rehabilitation following incomplete spinal cord injury (iSCI) often aims to enhance speed and stability. Concurrently increasing both may be difficult though as certain stabilization strategies will be compromised at faster speeds. To evaluate the interaction between speed and lateral stability, we examined individuals with (n = 12) and without (n = 12) iSCI as they performed straight walking and lateral maneuvers at Preferred and Fast treadmill speeds. To better detect the effects of speed on stability, we challenged lateral stability with a movement amplification force field. The Amplification field, created by a cable-driven robot, applied lateral forces to the pelvis that were proportional to the real-time lateral center of mass (COM) velocity. While we expected individuals to maintain stability during straight walking at the Fast speed in normal conditions, we hypothesized that both groups would be less stable in the Amplification field at the Fast speed compared to the Preferred. However, we found no effects of speed or the interaction between speed and field on straight-walking stability [Lyapunov exponent or lateral margin of stability (MOS)]. Across all trials at the Fast speed compared to the Preferred, there was greater step width variability (p = 0.031) and a stronger correlation between lateral COM state at midstance and the subsequent lateral foot placement. These observations suggest that increased stepping variability at faster speeds may be beneficial for COM control. We hypothesized that during lateral maneuvers in the Amplification field, MOS on the Initiation and Termination steps would be smaller at the Fast speed than at the Preferred. We found no effect of speed on the Initiation step MOS within either field (p > 0.350) or group (p > 0.200). The Termination step MOS decreased at the Fast speed within the group without iSCI (p < 0.001), indicating a trade-off between lateral stability and forward walking speed. Unexpectedly, participants took more steps and time to complete maneuvers at the Fast treadmill speed in the Amplification field. This strategy prioritizing stability over speed was especially evident in the group with iSCI. Overall, individuals with iSCI were able to maintain lateral stability when walking fast in balance-challenging conditions but may have employed more cautious maneuver strategies.

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