The spinal control of locomotion and step-to-step variability in left-right symmetry from slow to moderate speeds

When speed changes during locomotion, both temporal and spatial parameters of the pattern must adjust. Moreover, at slow speeds the step-to-step pattern becomes increasingly variable. The objectives of the present study were to assess if the spinal locomotor network adjusts both temporal and spatial parameters from slow to moderate stepping speeds and to determine if it contributes to step-to-step variability in left-right symmetry observed at slow speeds. To determine the role of the spinal locomotor network, the spinal cord of 6 adult cats was transected (spinalized) at low thoracic levels and the cats were trained to recover hindlimb locomotion. Cats were implanted with electrodes to chronically record electromyography (EMG) in several hindlimb muscles. Experiments began once a stable hindlimb locomotor pattern emerged. During experiments, EMG and bilateral video recordings were made during treadmill locomotion from 0.1 to 0.4 m/s in 0.05 m/s increments. Cycle and stance durations significantly decreased with increasing speed, whereas swing duration remained unaffected. Extensor burst duration significantly decreased with increasing speed, whereas sartorius burst duration remained unchanged. Stride length, step length, and the relative distance of the paw at stance offset significantly increased with increasing speed, whereas the relative distance at stance onset and both the temporal and spatial phasing between hindlimbs were unaffected. Both temporal and spatial step-to-step left-right asymmetry decreased with increasing speed. Therefore, the spinal cord is capable of adjusting both temporal and spatial parameters during treadmill locomotion, and it is responsible, at least in part, for the step-to-step variability in left-right symmetry observed at slow speeds.

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The influence of trunk extension in using advanced reciprocating gait orthosis on walking in spinal cord injury patients: A pilot study

Prosthetics and Orthotics International ◽

10.1177/0309364614531010 ◽

2014 ◽

Vol 39 (4) ◽

pp. 286-292 ◽

Cited By ~ 4

Author(s):

Mokhtar Arazpour ◽

Masoud Gharib ◽

Stephen William Hutchins ◽

Monireh Ahmadi Bani ◽

Sarah Curran ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Walking Speed ◽

Step Length ◽

Trunk Flexion ◽

Gait Parameters ◽

Cord Injury ◽

Before And After ◽

Spatial Parameters ◽

Trunk Extension

Background:Spinal cord injury patients walk with a flexed trunk when using reciprocating gait orthoses. Reduction of trunk flexion during ambulation may produce an improvement in gait parameters for reciprocating gait orthosis users.Objectives:To investigate the effect on kinematics and temporal–spatial parameters when spinal cord injury patients ambulate with an advanced reciprocating gait orthosis while wearing a thoracolumbosacral orthosis to provide trunk extension.Study design:Comparative study between before and after use o thoracolumbosacral orthosis with the advanced reciprocating gait orthoses.Methods:Four patients with spinal cord injury were fitted with an advanced reciprocating gait orthosis and also wore a thoracolumbosacral orthosis. Patients walked along a flat walkway either with or without the thoracolumbosacral orthosis at their self-selected walking speed. Temporal–spatial parameters and lower limb kinematics were analyzed.Results:Mean walking speed, step length, and cadence all improved when walking with the thoracolumbosacral orthosis donned compared to the trunk support offered by the advanced reciprocating gait orthosis. Hip and ankle joint ranges of motion were significantly increased when wearing the thoracolumbosacral orthosis during ambulation.Conclusion:Using an advanced reciprocating gait orthosis when wearing a thoracolumbosacral orthosis can improve walking speed and the step length of walking as compared with walking with an advanced reciprocating gait orthosis, probably due to the extended position of the trunk.Clinical relevanceDonning the thoracolumbosacral orthosis produced a relatively extended trunk position in the advanced reciprocating gait orthosis for all the patients included in the study, which resulted in improved gait parameters.

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Effect of powered gait orthosis on walking in individuals with paraplegia

Prosthetics and Orthotics International ◽

10.1177/0309364612463164 ◽

2012 ◽

Vol 37 (4) ◽

pp. 261-267 ◽

Cited By ~ 8

Author(s):

Mokhtar Arazpour ◽

Monireh Ahmadi Bani ◽

Reza Vahab Kashani ◽

Farhad Tabatabai Ghomshe ◽

Mohammad Ebrahim Mousavi ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Knee Joint ◽

Step Length ◽

Joint Kinematics ◽

Knee Joints ◽

Powered Gait Orthosis ◽

Cord Injury ◽

Knee Joint Kinematics ◽

Spatial Parameters

Background:The important purpose of a powered gait orthosis is to provide active joint movement for patients with spinal cord injury.Objectives:The aim of this study was to clarify the effect of a powered gait orthosis on the kinematics and temporal–spatial parameters in paraplegics with spinal cord injury.Study Design:Quasi-experimental.Methods:Four spinal cord injury individuals experienced gait training with a powered gait orthosis for a minimum of 6 weeks prior to participating in the following walking trials: walking with an isocentric reciprocating gait orthosis and walking with both separate and synchronized movements with actuated orthotic hip and knee joints in a powered gait orthosis. Specific parameters were calculated and compared for each of the test conditions.Results:Using separate and synchronized actuated movement of the hip and knee joints in the powered gait orthosis increased gait speed and step length and reduced lateral and vertical compensatory motions when compared to the isocentric reciprocating gait orthosis, but there were no significant differences in these parameters. Using the new powered gait orthosis improved knee and hip joint kinematics.Conclusions:The powered gait orthosis increased speed and step length as well as hip and knee joint kinematics and reduced the vertical and lateral compensatory motions compared to an isocentric reciprocating gait orthosis in spinal cord injury patients.Clinical relevanceThis new powered gait orthosis has the potential to improve hip and knee joint kinematics, the temporal–spatial parameters of gait in spinal cord injury patients walking.

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Evaluation of a novel powered hip orthosis for walking by a spinal cord injury patient: a single case study

Prosthetics and Orthotics International ◽

10.1177/0309364611431482 ◽

2012 ◽

Vol 36 (1) ◽

pp. 105-112 ◽

Cited By ~ 19

Author(s):

Mokhtar Arazpour ◽

Ahmad Chitsazan ◽

Stephen W Hutchins ◽

Farhad Tabatabai Ghomshe ◽

Mohammad Ebrahim Mousavi ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Hip Joint ◽

Single Case ◽

Step Length ◽

Spinal Cord Injury Patient ◽

Positive Effects ◽

Cord Injury ◽

Spatial Parameters

Background: The aim of this case study was to identify the effect of a powered hip orthosis on the kinematics and temporal-spatial parameters of walking by a patient with spinal cord injury (SCI).Case Description and Methods: Two orthoses were evaluated while worn by an incomplete SCI subject with a T-8level of injury. Gait evaluation was performed when walking with an Isocentric Reciprocating Gait Orthosis (IRGO) and compared to that demonstrated by a newly powered version of the orthosis; based on the IRGO superstructure but incorporating powered hip joints using an electrically motorized actuator that produced active hip joint extension and flexion.Findings and Outcomes: The powered hip orthosis, when compared to the IRGO, increased the speed of walking, the step length and also the cadence demonstrated by this subject. Vertical and horizontal compensatory motions with new orthosis decreased. Hip angles when walking with this orthosis were comparative to those demonstrated by normal walking patterns.Conclusions: The hip actuator produced positive effects on the kinematics and temporal-spatial parameters of gait during level-ground walking trials, resulting in an alternative approach to walking by SCI patients.Clinical relevanceThis orthosis has the potential to improve hip joint kinematics, the temporal-spatial parameters of gait in SCI patients walking.

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Comparison of gait between healthy participants and persons with spinal cord injury when using the advanced reciprocating gait orthosis

Prosthetics and Orthotics International ◽

10.1177/0309364615592699 ◽

2015 ◽

Vol 40 (2) ◽

pp. 287-293 ◽

Cited By ~ 1

Author(s):

Mokhtar Arazpour ◽

Mahmoud Joghtaei ◽

Mahmood Bahramizadeh ◽

Monireh Ahmadi Bani ◽

Stephen W Hutchins ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Range Of Motion ◽

Ankle Joint ◽

Step Length ◽

Foot Orthoses ◽

Normal Walking ◽

Cord Injury ◽

Ankle Foot Orthoses ◽

Spatial Parameters

Background:The advanced reciprocating gait orthosis (ARGO) has a rigid structure which provides restricted movement at the hip, knee, and ankle joints and incorporates a pelvic section with an extended section in the lumbar region. Healthy subjects, when walking with an RGO in situ, could feasibly demonstrate the level of limitation in movement imposed by ARGO-assisted ambulation.Objective:The aim of this study was to compare the function of the advanced reciprocating gait orthosis when fitted with the dorsiflexion-assist ankle–foot orthoses on temporal–spatial parameters and kinematics of walking in both able-bodied people and those with spinal cord injury.Study design:Quasi experimental design.Methods:Data were acquired from six able-bodied and four spinal cord injury subjects who used an advanced reciprocating gait orthosis which incorporated dorsiflexion-assist ankle–foot orthoses. Kinematics and temporal–spatial parameters were calculated and compared.Results:All able-bodied individuals walked with speeds which were only approximately one-third that of when walking without an orthosis. The mean step length and cadence were both reduced by 48% and 6%, respectively. There were significant differences in hip, knee, and ankle joint range of motions between normal walking and walking with the advanced reciprocating gait orthosis both in able-bodied subjects and patients with spinal cord injury. There were also significant differences in the speed of walking, cadence, step length, hip range of motion, and ankle range of motion when using the advanced reciprocating gait orthosis between the two groups.Conclusion:Temporal–spatial parameters and lower limb sagittal plane kinematics of walking were altered compared to normal walking, especially when spinal cord injury subjects walked with the advanced reciprocating gait orthosis compared to the able-bodied subjects.Clinical relevanceTo produce an improvement in RGO function, an increase in walking performance should involve attention to improvement of hip, knee, and ankle joint kinematics, which differs significantly from normal walking.

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