1. Targeted Walking in Incomplete Spinal Cord Injury: Role of Corticospinal Control
- Author
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Vinzenz von Tscharner, Armin Curt, Christopher Awai Easthope, Marc Bolliger, Christian Meyer, Tim Killeen, Stephanie A Stalder, Linard Filli, Björn Zörner, and University of Zurich
- Subjects
Adult ,Male ,030506 rehabilitation ,medicine.medical_specialty ,animal structures ,Pyramidal Tracts ,610 Medicine & health ,Electromyography ,Walking ,03 medical and health sciences ,0302 clinical medicine ,Physical medicine and rehabilitation ,medicine ,Humans ,Muscle, Skeletal ,Spinal cord injury ,Gait ,Spinal Cord Injuries ,Aged ,medicine.diagnostic_test ,business.industry ,Middle Aged ,medicine.disease ,Adaptation, Physiological ,Biomechanical Phenomena ,Gait analysis ,Exercise Test ,10046 Balgrist University Hospital, Swiss Spinal Cord Injury Center ,Female ,Neurology (clinical) ,Neuromuscular control ,0305 other medical science ,business ,030217 neurology & neurosurgery - Abstract
Locomotor recovery after incomplete spinal cord injury (iSCI) is influenced by spinal and supraspinal networks. Conventional clinical gait analysis fails to differentiate between these components. There is evidence that corticospinal control is enhanced during targeted walking, where each foot must be continuously placed on visual targets in randomized order. This study investigates the potential of targeted walking in the functional assessment of corticospinal integrity. Twenty-one controls and 16 individuals with chronic iSCI performed normal and targeted walking on a treadmill while electromyograms (EMGs) and kinematics were recorded. Precision (% of accurate foot placements) in targeted walking was significantly lower in individuals with iSCI (82.9 ± 14.7%, controls: 94.9 ± 4.0%). Although the overall kinematic pattern was comparable between walking conditions, controls showed significantly higher semitendinosus (ST) activity before heel-strike during targeted walking. This was accompanied by a shift of relative EMG intensity from 90-120 Hz to lower frequencies of 20-60 Hz, previously associated with corticospinal control of muscle activity. Targeted walking in individuals with iSCI evoked smaller EMG changes, suggesting that the switch to more corticospinal control is impaired. Accordingly, mildly impaired iSCI individuals revealed higher adaptations to the targeted walking task than more-impaired individuals. Recording of EMGs during targeted walking holds potential as a research tool to reveal further insights into the neuromuscular control of locomotion. It also complements findings of pre-clinical studies and is a promising novel surrogate marker of integrity of corticospinal control in individuals with iSCI and other neurological impairments. Future studies should investigate its potential for diagnosis or tracking recovery during rehabilitation.
- Published
- 2020