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.

Possible contributions of CPG activity to the control of rhythmic human arm movement

2004 ◽  
Vol 82 (8-9) ◽  
pp. 556-568 ◽  
Author(s):  
E Paul Zehr ◽  
Timothy J Carroll ◽  
Romeo Chua ◽  
David F Collins ◽  
Alain Frigon ◽  
...  
Keyword(s):  
Motor Control ◽  
Neural Control ◽  
Arm Movement ◽  
Rhythmic Movement ◽  
Lower Limbs ◽  
Reflex Modulation ◽  
Arm Cycling ◽  
Reflex Reversal ◽  
Arm Muscles ◽  
Leg Movement

There is extensive modulation of cutaneous and H-reflexes during rhythmic leg movement in humans. Mechanisms controlling reflex modulation (e.g., phase- and task-dependent modulation, and reflex reversal) during leg movements have been ascribed to the activity of spinal central pattern generating (CPG) networks and peripheral feedback. Our working hypothesis has been that neural mechanisms (i.e., CPGs) controlling rhythmic movement are conserved between the human lumbar and cervical spinal cord. Thus reflex modulation during rhythmic arm movement should be similar to that for rhythmic leg movement. This hypothesis has been tested by studying the regulation of reflexes in arm muscles during rhythmic arm cycling and treadmill walking. This paper reviews recent studies that have revealed that reflexes in arm muscles show modulation within the movement cycle (e.g., phase-dependency and reflex reversal) and between static and rhythmic motor tasks (e.g., task-dependency). It is concluded that reflexes are modulated similarly during rhythmic movement of the upper and lower limbs, suggesting similar motor control mechanisms. One notable exception to this pattern is a failure of contralateral arm movement to modulate reflex amplitude, which contrasts directly with observations from the leg. Overall, the data support the hypothesis that CPG activity contributes to the neural control of rhythmic arm movement.Key words: central pattern generator, locomotion, motor control, neural control.

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.

Development of an Apparatus for Bilateral Rhythmical Training of Arm Movement Via Linear and Elliptical Trajectories of Various Directions

2014 ◽  
Vol 8 (3) ◽  
Author(s):  
Zlatko Matjačić ◽  
Matjaž Zadravec ◽  
Jakob Oblak
Keyword(s):  
Muscle Activation ◽  
Arm Movement ◽  
Emg Activity ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Arm Cycling ◽  
Arm Reaching ◽  
Direction Of Movement ◽  
Muscle Groups ◽  
Neurologically Intact

Clinical rehabilitation of individuals with various neurological disorders requires a significant number of movement repetitions in order to improve coordination and restoration of appropriate muscle activation patterns. Arm reaching movement is frequently practiced via motorized arm cycling ergometers where the trajectory of movement is circular thus providing means for practicing a single and rather nonfunctional set of muscle activation patterns, which is a significant limitation. We have developed a novel mechanism that in the combination with an existing arm ergometer device enables nine different movement modalities/trajectories ranging from purely circular trajectory to four elliptical and four linear trajectories where the direction of movement may be varied. The main objective of this study was to test a hypothesis stating that different movement modalities facilitate differences in muscle activation patterns as a result of varying shape and direction of movement. Muscle activation patterns in all movement modalities were assessed in a group of neurologically intact individuals in the form of recording the electromyographic (EMG) activity of four selected muscle groups of the shoulder and the elbow. Statistical analysis of the root mean square (RMS) values of resulting EMG signals have shown that muscle activation patterns corresponding to each of the nine movement modalities significantly differ in order to accommodate to variation of the trajectories shape and direction. Further, we assessed muscle activation patterns following the same protocol in a selected clinical case of hemiparesis. These results have shown the ability of the selected case subject to produce different muscle activation patterns as a response to different movement modalities which show some resemblance to those assessed in the group of neurologically intact individuals. The results of the study indicate that the developed device may significantly extend the scope of strength and coordination training in stroke rehabilitation which is in current clinical rehabilitation practice done through arm cycling.

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.

Effect of afferent feedback and central motor commands on soleus H-reflex suppression during arm cycling

2012 ◽  
Vol 108 (11) ◽  
pp. 3049-3058 ◽  
Author(s):  
S. R. Hundza ◽  
Geoff C. de Ruiter ◽  
M. Klimstra ◽  
E. Paul Zehr
Keyword(s):  
Primary Source ◽  
Arm Movement ◽  
H Reflex ◽  
Afferent Feedback ◽  
Reflex Modulation ◽  
Muscle Vibration ◽  
Reflex Amplitude ◽  
Motor Commands ◽  
Arm Cycling ◽  
Central Motor Commands

Suppression of soleus H-reflex amplitude in stationary legs is seen during rhythmic arm cycling. We examined the influence of various arm-cycling parameters on this interlimb reflex modulation to determine the origin of the effect. We previously showed the suppression to be graded with the frequency of arm cycling but not largely influenced by changes in peripheral input associated with crank length. Here, we more explicitly explored the contribution of afferent feedback related to arm movement on the soleus H-reflex suppression. We explored the influence of load and rate of muscle stretch by manipulating crank-load and arm-muscle vibration during arm cycling. Furthermore, internally driven (“Active”) and externally driven (“Passive”) arm cycling was compared. Soleus H-reflexes were evoked with tibial nerve stimulation during stationary control and rhythmic arm-cycling conditions, including: 1) six different loads; 2) with and without vibration to arm muscles; and 3) Active and Passive conditions. No significant differences were seen in the level of suppression between the different crank loads or between conditions with and without arm-muscle vibration. Furthermore, in contrast to the clear effect seen during active cycling, passive arm cycling did not significantly suppress the soleus H-reflex amplitude. Current results, in conjunction with previous findings, suggest that the afferent feedback examined in these studies is not the primary source responsible for soleus H-reflex suppression. Instead, it appears that central motor commands (supraspinal or spinal in origin) associated with frequency of arm cycling are relatively more dominant sources.

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)

Asymmetry of Hindlimb Muscle Activity and Cutaneous Reflexes After Tendon Transfers in Kittens

1999 ◽  
Vol 82 (6) ◽  
pp. 3392-3405 ◽  
Author(s):  
G. E. Loeb
Keyword(s):  
Muscle Activity ◽  
Central Pattern Generators ◽  
Mechanical Action ◽  
Emg Activity ◽  
Sham Operation ◽  
Cutaneous Reflexes ◽  
Tendon Transfers ◽  
Cutaneous Reflex ◽  
Hindlimb Muscle ◽  
Pattern Generators

The mechanical actions of various ankle muscles were changed by surgically crossing or transferring the tendons in kittens. After the kittens grew to adults, both hindlimbs were implanted with multiple electromyogram (EMG) recording and cutaneous nerve stimulation electrodes to compare the activity of altered and normal muscles. The tendon transfers showed a remarkable tendency to regrow toward normal or only slightly altered mechanical action. In these animals and in the sham-operation controls, the patterns of muscle activity and reflexes were symmetrical in corresponding muscles of the two legs, although they could differ substantially between animals, particularly for the cutaneous reflexes. Eleven animals had at least some persistent alterations in muscle action. Their cutaneous reflex patterns tended to be asymmetric, in some cases quite markedly. EMG activity during unperturbed locomotion and paw-shaking was more symmetrical, but there were some changes in altered muscles and their synergists. The central pattern generators for locomotion and paw-shaking and particularly for cutaneous reflexes during locomotion appear to be at least partially malleable rather than entirely hardwired. This may provide a tool for studying their development and spinal plasticity in general.

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.

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