Shaping Appropriate Locomotive Motor Output Through Interlimb Neural Pathway Within Spinal Cord in Humans

Direct evidence supporting the contribution of upper limb motion on the generation of locomotive motor output in humans is still limited. Here, we aimed to examine the effect of upper limb motion on locomotor-like muscle activities in the lower limb in persons with spinal cord injury (SCI). By imposing passive locomotion-like leg movements, all cervical incomplete ( n = 7) and thoracic complete SCI subjects ( n = 5) exhibited locomotor-like muscle activity in their paralyzed soleus muscles. Upper limb movements in thoracic complete SCI subjects did not affect the electromyographic (EMG) pattern of the muscle activities. This is quite natural since neural connections in the spinal cord between regions controlling upper and lower limbs were completely lost in these subjects. On the other hand, in cervical incomplete SCI subjects, in whom such neural connections were at least partially preserved, the locomotor-like muscle activity was significantly affected by passively imposed upper limb movements. Specifically, the upper limb movements generally increased the soleus EMG activity during the backward swing phase, which corresponds to the stance phase in normal gait. Although some subjects showed a reduction of the EMG magnitude when arm motion was imposed, this was still consistent with locomotor-like motor output because the reduction of the EMG occurred during the forward swing phase corresponding to the swing phase. The present results indicate that the neural signal induced by the upper limb movements contributes not merely to enhance but also to shape the lower limb locomotive motor output, possibly through interlimb neural pathways. Such neural interaction between upper and lower limb motions could be an underlying neural mechanism of human bipedal locomotion.

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Metabolic Costs and Muscle Activity Patterns During Robotic- and Therapist-Assisted Treadmill Walking in Individuals With Incomplete Spinal Cord Injury

Physical Therapy ◽

10.2522/ptj.20050266 ◽

2006 ◽

Vol 86 (11) ◽

pp. 1466-1478 ◽

Cited By ~ 194

Author(s):

Jeffrey F Israel ◽

Donielle D Campbell ◽

Jennifer H Kahn ◽

T George Hornby

Keyword(s):

Spinal Cord ◽

Muscle Activity ◽

Activity Patterns ◽

Swing Phase ◽

Emg Activity ◽

Robotic Device ◽

Incomplete Spinal Cord Injury ◽

Robotic Assisted ◽

Cord Injury ◽

Metabolic Costs

AbstractBackground and Purpose. Robotic devices that provide passive guidance and stabilization of the legs and trunk during treadmill stepping may increase the delivery of locomotor training to subjects with neurological injury. Lower-extremity guidance also may reduce voluntary muscle activity as compared with compliant assistance provided by therapists. The purpose of this study was to investigate differences in metabolic costs and lower-limb muscle activity patterns during robotic- and therapist-assisted treadmill walking. Subjects. Twelve ambulatory subjects with motor incomplete spinal cord injury participated. Methods. In 2 separate protocols, metabolic and electromyographic (EMG) data were collected during standing and stepping on a treadmill with therapist and robotic assistance. During robotic-assisted walking, subjects were asked to match the kinematic trajectories of the device and maximize their effort. During therapist-assisted walking, subjects walked on the treadmill with manual assistance provided as necessary. Results. Metabolic costs and swing-phase hip flexor EMG activity were significantly lower when subjects were asked to match the robotic device trajectories than with therapist-assisted walking. These differences were reduced when subjects were asked to maximize their effort during robotic-assisted stepping, although swing-phase plantar-flexor EMG activity was increased. In addition, during standing prior to therapist- or robotic-assisted stepping, metabolic costs were higher without stabilization from the robotic device. Discussion and Conclusion. Differences in metabolic costs and muscle activity patterns between therapist- and robotic-assisted standing and stepping illustrate the importance of minimizing passive guidance and stabilization provided during step training protocols.

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A Simplified Stroke Rehabilitation Assessment of Movement Instrument

Physical Therapy ◽

10.1093/ptj/86.7.936 ◽

2006 ◽

Vol 86 (7) ◽

pp. 936-943 ◽

Cited By ~ 24

Author(s):

I-Ping Hsueh ◽

Wen-Chung Wang ◽

Chun-Hou Wang ◽

Ching-Fan Sheu ◽

Sing-Kai Lo ◽

...

Keyword(s):

Upper Limb ◽

Rasch Model ◽

Lower Limb ◽

Concurrent Validity ◽

Stroke Rehabilitation ◽

Rasch Analysis ◽

Limb Movements ◽

Upper Limb Movements ◽

Valid Instrument ◽

Rehabilitation Assessment

Abstract Background and Purpose. An efficient, reliable, and valid instrument for assessing motor function in patients with stroke is needed by both clinicians and researchers. To improve administration efficiency, we applied the multidimensional Rasch model to the 30-item, 3-subscale Stroke Rehabilitation Assessment of Movement (STREAM) instrument to produce a concise, reliable, and valid instrument (simplified STREAM [S-STREAM]) for measuring motor function in patients with stroke. Subjects and Methods. The STREAM (consisting of 3 subscales: upper-limb movements, lower-limb movements, and mobility) was administered to 351 subjects with first stroke occurrence and a median time after stroke of 12.5 months. The unidimensionality of each subscale of the STREAM first was verified with unidimensional Rasch analysis. Each subscale of the STREAM then was simplified by deleting redundant items on the basis of expert opinion and the results of the Rasch analysis. The Rasch reliability of the S-STREAM and the concurrent validity of the S-STREAM with the STREAM were examined with multidimensional Rasch analysis and the intraclass correlation coefficient (ICC), respectively. Results. After deleting the items that did not fit the Rasch model, we found that the 8-item upper-limb movement subscale, the 9-item lower-limb movement subscale, and the 10-item mobility subscale assessed single, unidimensional upper-limb movements, lower-limb movements, and mobility, respectively. We selected 5 items from each subscale to construct the S-STREAM and found that the reliability of each subscale of the resulting simplified instrument was high (Rasch reliability coefficients of ≥.91). The agreement between the subscale scores (Rasch estimates) of the S-STREAM and those of the STREAM was excellent (ICC of ≥.99, with a lower limit for the 95% confidence interval of ≥.985), indicating good concurrent validity of the S-STREAM with the STREAM. Discussion and Conclusion. The S-STREAM demonstrates high Rasch reliability, unidimensionality, and concurrent validity with the STREAM in patients with stroke. Furthermore, the S-STREAM is efficient to administer, as it consists of only half the number of items in the original STREAM. Additional studies to examine other psychometric properties (eg, predictive validity and responsiveness) of the S-STREAM or its psychometric properties in various recovery stages after stroke are needed to further establish its utility in both clinical and research settings.

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Synchronisation and correction of stepping to phase-perturbed multisensory metronome cues

Seeing and Perceiving ◽

10.1163/187847612x647928 ◽

2012 ◽

Vol 25 (0) ◽

pp. 161-162

Author(s):

Rachel L. Wright ◽

Mark T. Elliott ◽

Laura C. Spurgeon ◽

Alan M. Wing

Keyword(s):

Upper Limb ◽

Lower Limb ◽

Sensory Modality ◽

Auditory Modality ◽

Limb Movements ◽

Bimodal Condition ◽

Phase Perturbation ◽

Upper Limb Movements ◽

The Central Nervous System ◽

Multisensory Cues

When information is available in more than one sensory modality, the central nervous system will integrate the cues to obtain a statistically optimal estimate of the event or object perceived (Alais and Burr, 2004; Ernst and Banks, 2002). For synchronising movements to a stream of events, this multisensory advantage is observed with reduced temporal variability of the movements compared to unimodal conditions (Elliott et al., 2010, 2011; Wing et al., 2010). Currently, this has been demonstrated for upper limb movements (finger tapping). Here, we investigate synchronisation of lower limb movements (stepping on the spot) to auditory, visual and combined auditory-visual metronome cues. In addition, we compare movement corrections to a phase perturbation in the metronome for the three sensory modality conditions. We hypothesised that, as with upper limb movements, there would be a multisensory advantage, with stepping variability being lowest in the bimodal condition. As such, we further expected correction to the phase perturbation to be quickest in the bimodal condition. Our results show that while we see evidence of multisensory integration taking place, there was no multisensory advantage in the phase correction task — correction under the bimodal condition was almost identical to the auditory-only condition. Both bimodal and auditory-only conditions showed larger corrections for each step after the perturbation, compared to the visual-only condition. We conclude that rapid lower limb corrections are possible when synchronising with salient, regular auditory cues, such that integration of information from other modalities does not improve correction efficiency. However, if the auditory modality is less reliable it is likely that multisensory cues would become advantageous in such a task.

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Instrumental evaluation of upper limb movements in subjects after cervical spinal cord injury

Gait & Posture ◽

10.1016/j.gaitpost.2017.07.076 ◽

2017 ◽

Vol 57 ◽

pp. 21-22

Author(s):

E. Galofaro ◽

A. Deluca ◽

C. Pierella ◽

E. Tasso ◽

F. Cervetto ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Upper Limb ◽

Cervical Spinal Cord ◽

Cervical Spinal Cord Injury ◽

Limb Movements ◽

Instrumental Evaluation ◽

Cord Injury ◽

Upper Limb Movements

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Rostrocaudal Distribution of the C-Fos-Immunopositive Spinal Network Defined by Muscle Activity during Locomotion

Brain Sciences ◽

10.3390/brainsci11010069 ◽

2021 ◽

Vol 11 (1) ◽

pp. 69

Author(s):

Natalia Merkulyeva ◽

Vsevolod Lyakhovetskii ◽

Aleksandr Veshchitskii ◽

Oleg Gorskii ◽

Pavel Musienko

Keyword(s):

Spinal Cord ◽

Locomotor Activity ◽

Control Systems ◽

Muscle Activity ◽

Knee Extensors ◽

Emg Activity ◽

Lumbosacral Spinal Cord ◽

Adductor Muscles ◽

Spinal Network ◽

Hip Flexor

The optimization of multisystem neurorehabilitation protocols including electrical spinal cord stimulation and multi-directional tasks training require understanding of underlying circuits mechanisms and distribution of the neuronal network over the spinal cord. In this study we compared the locomotor activity during forward and backward stepping in eighteen adult decerebrated cats. Interneuronal spinal networks responsible for forward and backward stepping were visualized using the C-Fos technique. A bi-modal rostrocaudal distribution of C-Fos-immunopositive neurons over the lumbosacral spinal cord (peaks in the L4/L5 and L6/S1 segments) was revealed. These patterns were compared with motoneuronal pools using Vanderhorst and Holstege scheme; the location of the first peak was correspondent to the motoneurons of the hip flexors and knee extensors, an inter-peak drop was presumably attributed to the motoneurons controlling the adductor muscles. Both were better expressed in cats stepping forward and in parallel, electromyographic (EMG) activity of the hip flexor and knee extensors was higher, while EMG activity of the adductor was lower, during this locomotor mode. On the basis of the present data, which showed greater activity of the adductor muscles and the attributed interneuronal spinal network during backward stepping and according with data about greater demands on postural control systems during backward locomotion, we suppose that the locomotor networks for movements in opposite directions are at least partially different.

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