scholarly journals A Spinal Mechanism Related to Left–Right Symmetry Reduces Cutaneous Reflex Modulation Independently of Speed During Split-Belt Locomotion

2018 ◽  
Vol 38 (48) ◽  
pp. 10314-10328 ◽  
Author(s):  
Marie-France Hurteau ◽  
Alain Frigon
Keyword(s):  
Reflex Modulation ◽  
Cutaneous Reflex ◽  
Spinal Mechanism

scholarly journals Exploiting Interlimb Arm and Leg Connections for Walking Rehabilitation: A Training Intervention in Stroke

2016 ◽  
Vol 2016 ◽  
pp. 1-19 ◽  
Author(s):  
Taryn Klarner ◽  
Trevor S. Barss ◽  
Yao Sun ◽  
Chelsea Kaupp ◽  
Pamela M. Loadman ◽  
...  
Keyword(s):  
Neural Control ◽  
Cost Effective ◽  
Treadmill Walking ◽  
Reflex Modulation ◽  
Walking Ability ◽  
Cutaneous Reflex ◽  
Walking Rehabilitation ◽  
Increased Strength ◽  
Stride Duration ◽  
Cycling Training

Rhythmic arm and leg (A&L) movements share common elements of neural control. The extent to which A&L cycling training can lead to training adaptations which transfer to improved walking function remains untested. The purpose of this study was to test the efficacy of A&L cycling training as a modality to improve locomotor function after stroke. Nineteen chronic stroke (>six months) participants were recruited and performed 30 minutes of A&L cycling training three times a week for five weeks. Changes in walking function were assessed with (1) clinical tests; (2) strength during isometric contractions; and (3) treadmill walking performance and cutaneous reflex modulation. A multiple baseline (3 pretests) within-subject control design was used. Data show that A&L cycling training improved clinical walking status increased strength by ~25%, improved modulation of muscle activity by ~25%, increased range of motion by ~20%, decreased stride duration, increased frequency, and improved modulation of cutaneous reflexes during treadmill walking. On most variables, the majority of participants showed a significant improvement in walking ability. These results suggest that exploiting arm and leg connections with A&L cycling training, an accessible and cost-effective training modality, could be used to improve walking ability after stroke.

Effects of chronic ankle instability on cutaneous reflex modulation during walking

2019 ◽  
Vol 237 (8) ◽  
pp. 1959-1971 ◽  
Author(s):  
Leif P. Madsen ◽  
Koichi Kitano ◽  
David M. Koceja ◽  
E. Paul Zehr ◽  
Carrie L. Docherty
Keyword(s):  
Ankle Instability ◽  
Chronic Ankle Instability ◽  
Reflex Modulation ◽  
Cutaneous Reflex

scholarly journals Bipedal reflex coordination to tactile stimulation of the sural nerve during human running

1995 ◽  
Vol 73 (5) ◽  
pp. 1947-1964 ◽  
Author(s):  
A. A. Tax ◽  
B. M. Van Wezel ◽  
V. Dietz
Keyword(s):  
Sural Nerve ◽  
Elementary Property ◽  
Emg Activity ◽  
Reflex Modulation ◽  
Step Cycle ◽  
Perception Threshold ◽  
Reflex Responses ◽  
Cutaneous Reflex ◽  
Human Running ◽  
Stimulation Of

1. Cutaneous reflex responses were elicited during human running (8 km/h) on a treadmill by electrical stimulation of the sural nerve at the ankle. Stimulus trains (5 pulses of 1 ms at 200 Hz) at three nonnociceptive intensities, which were 1.5, 2.0, and 2.5 times perception threshold (PT), were delivered at 16 phases of the step cycle. For 11 subjects the surface electromyographic (EMG) activity of both the ipsilateral and contralateral long head of the biceps femoris (iBF and cBF, respectively), the semitendinosus (iST and cST), the rectus femoris (iRF and cRF), and the tibialis anterior (iTA and cTA) were recorded. 2. During human running nonnociceptive sural nerve stimulation appears to be sufficient to elicit large, widespread and statistically significant reflex responses, with a latency of approximately 80 ms and a duration of approximately 30 ms. These reflex responses seem to be an elementary property of human locomotion. This is indicated by the occurrence of the responses in all subjects, the consistency of most of the reflex patterns across the subjects and, apart from a small amount of habituation, the reproducibility of the responses during the course of the experiment. 3. The responses are modulated continuously throughout the step cycle such that their magnitude does not in general covary with the background locomotor activities. This is observed most clearly in iST, iTA, and cTA for which statistically significant reflex reversals are demonstrated, and in cRF and cTA for which the responses are gated during most of the step cycle. 4. The response magnitude generally increases as a function of increasing intensity, whereas the phase-dependent reflex modulation is intensity independent. 5. A functional dissociation within the ipsilateral hamstring muscles is demonstrated: the iBF and iST show an antagonistic reflex pattern (facilitatory and suppressive, respectively) during the periods of synergistic background locomotor activity in the step cycle. Contralaterally, however, the cBF and cST are reflexively activated as close synergists during these periods. 6. The reflex responses and their phase-dependent modulation are different for the homologous muscles in the two legs. Yet, some similarities are observed. These are present rather with respect to the phase of the corresponding leg than with respect to the phase of the stimulated leg. Both observations suggest that the phase-dependent reflex modulation is controlled separately in the ipsilateral and contralateral legs. 7. The response simultaneity in all investigated muscles supports the notion of a coordinated cutaneous interlimb reflex during human running.(ABSTRACT TRUNCATED AT 400 WORDS)

Prior experience does not alter modulation of cutaneous reflexes during manual wheeling and symmetrical arm cycling

2013 ◽  
Vol 109 (9) ◽  
pp. 2345-2353 ◽  
Author(s):  
Megan K. MacGillivray ◽  
Marc Klimstra ◽  
Bonita Sawatzky ◽  
E. Paul Zehr ◽  
Tania Lam
Keyword(s):  
Amplitude Modulation ◽  
Reflex Response ◽  
Reflex Modulation ◽  
Cutaneous Reflexes ◽  
Triceps Brachii ◽  
Reflex Amplitude ◽  
Cutaneous Reflex ◽  
Arm Cycling ◽  
Cyclic Movements ◽  
Middle Latency

Previous research has reported that training and experience influence H-reflex amplitude during rhythmic activity; however, little research has yet examined the influence of training on cutaneous reflexes. Manual wheelchair users (MWUs) depend on their arms for locomotion. We postulated that the daily dependence and high amount of use of the arms for mobility in MWUs would show differences in cutaneous reflex modulation during upper limb cyclic movements compared with able-bodied control subjects. We hypothesized that MWUs would demonstrate increased reflex response amplitudes for both manual wheeling and symmetrical arm cycling tasks. The superficial radial nerve was stimulated randomly at different points of the movement cycle of manual wheeling and symmetrical arm cycling in MWUs and able-bodied subjects naive to wheeling. Our results showed that there were no differences in amplitude modulation of early- or middle-latency cutaneous reflexes between the able-bodied group and the MWU group. However, there were several differences in amplitude modulation of cutaneous reflexes between tasks (manual wheeling and symmetrical arm cycling). Specifically, differences were observed in early-latency responses in the anterior and posterior deltoid muscles and biceps and triceps brachii as well as in middle-latency responses in the anterior and posterior deltoid. These data suggest that manual wheeling experience does not modify the pattern of cutaneous reflex amplitude modulation during manual wheeling. The differences in amplitude modulation of cutaneous reflexes between tasks may be a result of mechanical differences (i.e., hand contact) between tasks.

scholarly journals Rhythmic arm cycling training improves walking and neurophysiological integrity in chronic stroke: the arms can give legs a helping hand in rehabilitation

2018 ◽  
Vol 119 (3) ◽  
pp. 1095-1112 ◽  
Author(s):  
Chelsea Kaupp ◽  
Gregory E. P. Pearcey ◽  
Taryn Klarner ◽  
Yao Sun ◽  
Hilary Cullen ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Chronic Stroke ◽  
Reflex Modulation ◽  
Walking Ability ◽  
Functional Rehabilitation ◽  
Cutaneous Reflex ◽  
Arm Cycling ◽  
Interlimb Coupling ◽  
Before And After ◽  
Cycling Training

Training locomotor central pattern-generating networks (CPGs) through arm and leg cycling improves walking in chronic stroke. These outcomes are presumed to result from enhanced interlimb connectivity and CPG function. The extent to which rhythmic arm training activates interlimb CPG networks for locomotion remains unclear and was assessed by studying chronic stroke participants before and after 5 wk of arm cycling training. Strength was assessed bilaterally via maximal voluntary isometric contractions in the legs and hands. Muscle activation during arm cycling and transfer to treadmill walking were assessed in the more affected (MA) and less affected (LA) sides via surface electromyography. Changes to interlimb coupling during rhythmic movement were evaluated using modulation of cutaneous reflexes elicited by electrical stimulation of the superficial radial nerve at the wrist. Bilateral soleus stretch reflexes were elicited at rest and during 1-Hz arm cycling. Clinical function tests assessed walking, balance, and motor function. Results show significant changes in function and neurophysiological integrity. Training increased bilateral grip strength, force during MA plantarflexion, and muscle activation. “Normalization” of cutaneous reflex modulation was found during arm cycling. There was enhanced activity in the dorsiflexor muscles on the MA side during the swing phase of walking. Enhanced interlimb coupling was shown by increased modulation of MA soleus stretch reflex amplitudes during arm cycling after training. Clinical evaluations showed enhanced walking ability and balance. These results are consistent with training-induced changes in CPG function and interlimb connectivity and underscore the need for arm training in the functional rehabilitation of walking after neurotrauma.NEW & NOTEWORTHY It has been suggested but not tested that training the arms may influence rehabilitation of walking due to activation of interneuronal patterning networks after stroke. We show that arm cycling training improves strength, clinical function, coordination of muscle activity during walking, and neurological connectivity between the arms and the legs. The arms can, in fact, give the legs a helping hand in rehabilitation of walking after stroke.

scholarly journals Cutaneous reflex modulation and self-induced reflex attenuation in cerebellar patients

2015 ◽  
Vol 113 (3) ◽  
pp. 915-924 ◽  
Author(s):  
Wouter Hoogkamer ◽  
Frank Van Calenbergh ◽  
Stephan P. Swinnen ◽  
Jacques Duysens
Keyword(s):  
Muscle Activity ◽  
Neural Control ◽  
Biceps Femoris ◽  
Reflex Modulation ◽  
Neural Pathways ◽  
Common View ◽  
Control Subjects ◽  
Leg Muscles ◽  
Cutaneous Reflex ◽  
Healthy Control

Modulation of cutaneous reflexes is important in the neural control of walking, yet knowledge about underlying neural pathways is still incomplete. Recent studies have suggested that the cerebellum is involved. Here we evaluated the possible roles of the cerebellum in cutaneous reflex modulation and in attenuation of self-induced reflexes. First we checked whether leg muscle activity during walking was similar in patients with focal cerebellar lesions and in healthy control subjects. We then recorded cutaneous reflex activity in leg muscles during walking. Additionally, we compared reflexes after standard (computer triggered) stimuli with reflexes after self-induced stimuli for both groups. Biceps femoris and gastrocnemius medialis muscle activity was increased in the patient group compared with the control subjects, suggesting a coactivation strategy to reduce instability of gait. Cutaneous reflex modulation was similar between healthy control subjects and cerebellar patients, but the latter appeared less able to attenuate reflexes to self-induced stimuli. This suggests that the cerebellum is not primarily involved in cutaneous reflex modulation but that it could act in attenuation of self-induced reflex responses. The latter role in locomotion would be consistent with the common view that the cerebellum predicts sensory consequences of movement.

scholarly journals Neural control of rhythmic arm cycling after stroke

2012 ◽  
Vol 108 (3) ◽  
pp. 891-905 ◽  
Author(s):  
E. Paul Zehr ◽  
Pamela M. Loadman ◽  
Sandra R. Hundza
Keyword(s):  
Neural Control ◽  
Arm Movement ◽  
Constant Current ◽  
Cycle Phase ◽  
Emg Activity ◽  
Reflex Modulation ◽  
Cutaneous Reflexes ◽  
Cutaneous Reflex ◽  
Arm Cycling ◽  
Modulation Pattern

Disordered reflex activity and alterations in the neural control of walking have been observed after stroke. In addition to impairments in leg movement that affect locomotor ability after stroke, significant impairments are also seen in the arms. Altered neural control in the upper limb can often lead to altered tone and spasticity resulting in impaired coordination and flexion contractures. We sought to address the extent to which the neural control of movement is disordered after stroke by examining the modulation pattern of cutaneous reflexes in arm muscles during arm cycling. Twenty-five stroke participants who were at least 6 mo postinfarction and clinically stable, performed rhythmic arm cycling while cutaneous reflexes were evoked with trains (5 × 1.0-ms pulses at 300 Hz) of constant-current electrical stimulation to the superficial radial (SR) nerve at the wrist. Both the more (MA) and less affected (LA) arms were stimulated in separate trials. Bilateral electromyography (EMG) activity was recorded from muscles acting at the shoulder, elbow, and wrist. Analysis was conducted on averaged reflexes in 12 equidistant phases of the movement cycle. Phase-modulated cutaneous reflexes were present, but altered, in both MA and LA arms after stroke. Notably, the pattern was “blunted” in the MA arm in stroke compared with control participants. Differences between stroke and control were progressively more evident moving from shoulder to wrist. The results suggest that a reduced pattern of cutaneous reflex modulation persists during rhythmic arm movement after stroke. The overall implication of this result is that the putative spinal contributions to rhythmic human arm movement remain accessible after stroke, which has translational implications for rehabilitation.

Forward and Backward Arm Cycling Are Regulated by Equivalent Neural Mechanisms

2005 ◽  
Vol 93 (1) ◽  
pp. 633-640 ◽  
Author(s):  
E. Paul Zehr ◽  
Sandra R. Hundza
Keyword(s):  
Neural Control ◽  
Arm Movement ◽  
Movement Direction ◽  
Reflex Modulation ◽  
Neural Activation ◽  
Cutaneous Reflexes ◽  
Leg Muscles ◽  
Cutaneous Reflex ◽  
Arm Cycling ◽  
Walking Activity

It was shown some time ago that cutaneous reflexes were phase-reversed when comparing forward and backward treadmill walking. Activity of central-pattern-generating networks (CPG) regulating neural activity for locomotion was suggested as a mechanism involved in this “program reversal.” We have been investigating the neural control of arm movements and the role for CPG mechanisms in regulating rhythmic arm cycling. The purpose of this study was to evaluate the pattern of muscle activity and reflex modulation when comparing forward and backward arm cycling. During rhythmic arm cycling (forward and backward), cutaneous reflexes were evoked with trains (5 × 1.0 ms pulses at 300 Hz) of electrical stimulation delivered to the superficial radial (SR) nerve at the wrist. Electromyographic (EMG) recordings were made bilaterally from muscles acting at the shoulder, elbow, and wrist. Analysis was conducted on specific sections of the movement cycle after phase-averaging contingent on the timing of stimulation in the movement cycle. EMG patterns for rhythmic arm cycling are similar during both forward and backward motion. Cutaneous reflex amplitudes were similarly modulated at both early and middle latency irrespective of arm cycling direction. That is, at similar phases in the movement cycle, responses of corresponding sign and amplitude were seen regardless of movement direction. The results are generally parallel to the observations seen in leg muscles after stimulation of cutaneous nerves in the foot during forward and backward walking and provide further evidence for CPG activity contributing to neural activation and reflex modulation during rhythmic arm movement.

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