INFLUENCE OF INCOMPLETE SPINAL CORD INJURY ON LOWER EXTREMITY MUSCLE MASS

Transcutaneous (TSS) and epidural spinal stimulation (ESS) are electrophysiological techniques that have been used to investigate the interactions between exogenous electrical stimuli and spinal sensorimotor networks that integrate descending motor signals with afferent inputs from the periphery during motor tasks such as standing and stepping. Recently, pilot-phase clinical trials using ESS and TSS have demonstrated restoration of motor functions that were previously lost due to spinal cord injury (SCI). However, the spinal network interactions that occur in response to TSS or ESS pulses with spared descending connections across the site of SCI have yet to be characterized. Therefore, we examined the effects of delivering TSS or ESS pulses to the lumbosacral spinal cord in nine individuals with chronic SCI. During low-frequency stimulation, participants were instructed to relax or attempt maximum voluntary contraction to perform full leg flexion while supine. We observed similar lower-extremity neuromusculature activation during TSS and ESS when performed in the same participants while instructed to relax. Interestingly, when participants were instructed to attempt lower-extremity muscle contractions, both TSS- and ESS-evoked motor responses were significantly inhibited across all muscles. Participants with clinically complete SCI tested with ESS and participants with clinically incomplete SCI tested with TSS demonstrated greater ability to modulate evoked responses than participants with motor complete SCI tested with TSS, although this was not statistically significant due to a low number of subjects in each subgroup. These results suggest that descending commands combined with spinal stimulation may increase activity of inhibitory interneuronal circuitry within spinal sensorimotor networks in individuals with SCI, which may be relevant in the context of regaining functional motor outcomes.

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Walking with and without a robotic exoskeleton in people with incomplete spinal cord injury compared to a typical gait pattern

Neurorehabilitation ◽

10.3233/nre-210187 ◽

2021 ◽

pp. 1-12

Author(s):

Sattam M. Almutairi ◽

Chad Swank ◽

Sharon S. Wang-Price ◽

Fan Gao ◽

Ann Medley

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Lower Extremity ◽

Rectus Femoris ◽

Gait Pattern ◽

Healthy Adults ◽

Incomplete Spinal Cord Injury ◽

Lower Extremity Weakness ◽

Robotic Exoskeleton ◽

Cord Injury

BACKGROUND: Robotic exoskeleton (RE) enables individuals with lower extremity weakness or paralysis to stand and walk in a stereotypical pattern. OBJECTIVE: Examine whether people with chronic incomplete spinal cord injury (SCI) demonstrate a more typical gait pattern when walking overground in a RE than when walking without. METHODS: Motion analysis system synchronized with a surface electromyographic (EMG) was used to obtain temporospatial gait parameters, lower extremity kinematics, and muscle activity in ambulatory individuals with SCI and healthy adults. RESULTS: Temporospatial parameters and kinematics for participants with SCI (n = 12; age 41.4±12.5 years) with and without RE were significantly different than a typical gait (healthy adults: n = 15; age 26.2±8.3 years). EMG amplitudes during the stance phase of a typical gait were similar to those with SCI with and without RE, except the right rectus femoris (p = 0.005) and left gluteus medius (p = 0.014) when participants with SCI walked with RE. EMG amplitudes of participants with SCI during the swing phase were significantly greater compared to those of a typical gait, except for left medial hamstring with (p = 0.025) and without (p = 0.196) RE. CONCLUSIONS: First-time walking in a RE does not appear to produce a typical gait pattern in people with incomplete SCI.

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The Effectiveness and Safety of Exoskeletons as Assistive and Rehabilitation Devices in the Treatment of Neurologic Gait Disorders in Patients with Spinal Cord Injury: A Systematic Review

Global Spine Journal ◽

10.1055/s-0036-1593805 ◽

2016 ◽

Vol 6 (8) ◽

pp. 822-841 ◽

Cited By ~ 35

Author(s):

Christian Fisahn ◽

Mirko Aach ◽

Oliver Jansen ◽

Marc Moisi ◽

Angeli Mayadev ◽

...

Keyword(s):

Systematic Review ◽

Spinal Cord ◽

Spinal Cord Injury ◽

Lower Extremity ◽

Assistive Device ◽

Walk Test ◽

Incomplete Spinal Cord Injury ◽

Lower Extremity Function ◽

Extremity Function ◽

Cord Injury

Study Design Systematic review. Clinical Questions (1) When used as an assistive device, do wearable exoskeletons improve lower extremity function or gait compared with knee-ankle-foot orthoses (KAFOs) in patients with complete or incomplete spinal cord injury? (2) When used as a rehabilitation device, do wearable exoskeletons improve lower extremity function or gait compared with other rehabilitation strategies in patients with complete or incomplete spinal cord injury? (3) When used as an assistive or rehabilitation device, are wearable exoskeletons safe compared with KAFO for assistance or other rehabilitation strategies for rehabilitation in patients with complete or incomplete spinal cord injury? Methods PubMed, Cochrane, and Embase databases and reference lists of key articles were searched from database inception to May 2, 2016, to identify studies evaluating the effectiveness of wearable exoskeletons used as assistive or rehabilitative devices in patients with incomplete or complete spinal cord injury. Results No comparison studies were found evaluating exoskeletons as an assistive device. Nine comparison studies (11 publications) evaluated the use of exoskeletons as a rehabilitative device. The 10-meter walk test velocity and Spinal Cord Independence Measure scores showed no difference in change from baseline among patients undergoing exoskeleton training compared with various comparator therapies. The remaining primary outcome measures of 6-minute walk test distance and Walking Index for Spinal Cord Injury I and II and Functional Independence Measure–Locomotor scores showed mixed results, with some studies indicating no difference in change from baseline between exoskeleton training and comparator therapies, some indicating benefit of exoskeleton over comparator therapies, and some indicating benefit of comparator therapies over exoskeleton. Conclusion There is no data to compare locomotion assistance with exoskeleton versus conventional KAFOs. There is no consistent benefit from rehabilitation using an exoskeleton versus a variety of conventional methods in patients with chronic spinal cord injury. Trials comparing later-generation exoskeletons are needed.

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