Adaptation of Cutaneous Stumble Correction When Tripping Is Part of the Locomotor Environment

2008 ◽  
Vol 99 (6) ◽  
pp. 2789-2797 ◽  
Author(s):  
Carlos Haridas ◽  
E. Paul Zehr ◽  
John E. Misiaszek
Keyword(s):  
Medial Gastrocnemius ◽  
Whole Body ◽  
General Nature ◽  
Cutaneous Reflexes ◽  
Step Cycle ◽  
Cutaneous Reflex ◽  
Postural Threat ◽  
Functional Relevance ◽  
Five Phases ◽  
Stimulation Of

We recently showed that cutaneous reflexes evoked by stimulating the superficial peroneal (SP; innervates foot dorsum) nerve are modulated according to the level of postural threat. Context-related modulation was observed mainly in contralateral (c) responses but not in the ipsilateral responses. This lack of effect on ipsilateral (i) cutaneous reflexes might have been caused by the general nature of the whole body perturbation. We therefore hypothesized that context-relevant mechanical perturbations applied to the dorsum of the foot by an instrumented rod at early swing during walking would produce differences in ipsilateral cutaneous reflex amplitudes, consistent with the functional relevance of the SP nerve in stumble correction responses. Subjects walked on a motorized treadmill under four conditions: 1) normal, 2) normal with mechanical perturbations at the foot dorsum, 3) arms crossed, and 4) arms crossed with mechanical perturbations at the foot dorsum. Electrical stimulation of the SP nerve was delivered at five phases of the step cycle, and cutaneous reflexes were compared between all conditions for each phase of the step cycle. Reflex responses were generally found to be modulated in amplitude during walking conditions in which mechanical perturbations were delivered, particularly in ipsilateral tibialis anterior (iTA), which showed a marked reduction in inhibition. The results indicated cutaneous reflexes in iTA and contralateral medial gastrocnemius (cMG) were influenced by the threat of a trip, induced by applying mechanical perturbations to the foot dorsum during walking. This task-related gating of cutaneous reflexes was not generalized to all muscles, thus suggesting a functional role in the maintenance of stability during locomotion.

Context-Dependent Modulation of Interlimb Cutaneous Reflexes in Arm Muscles as a Function of Stability Threat During Walking

2006 ◽  
Vol 96 (6) ◽  
pp. 3096-3103 ◽  
Author(s):  
Carlos Haridas ◽  
E. Paul Zehr ◽  
John E. Misiaszek
Keyword(s):  
Electrical Stimulation ◽  
Cutaneous Reflexes ◽  
Step Cycle ◽  
Functional Link ◽  
Leg Muscles ◽  
Postural Threat ◽  
Arm Muscles ◽  
The Right ◽  
Anterior Posterior ◽  
Stimulation Of

Cutaneous reflexes evoked in the muscles of the arms with electrical stimulation of nerves of the foot (“interlimb reflexes”) are observed during walking. These reflexes have been suggested to coordinate the actions of the legs and arms when walking is disturbed. Recently, we showed that cutaneous reflexes evoked in the leg muscles after stimulation at the foot are modulated according to the level of postural threat during walking. We hypothesized that the amplitude of interlimb cutaneous reflexes would similarly be modulated when subjects walk in unstable environments. Subjects walked on a treadmill under four walking conditions: 1) normal; 2) normal with unpredictable anterior–posterior (AP) perturbations; 3) arms crossed; and 4) arms crossed with unpredictable AP perturbations. Interlimb reflexes evoked from electrical stimulation of the right superficial peroneal or sural nerves were recorded bilaterally, at four points of the step cycle. These reflexes were compared between conditions in which the arms were moving in a similar manner: 1) normal versus AP walking and 2) arms crossed versus arms crossed with AP perturbations. Differences in reflex amplitudes between arms-crossed conditions were observed in most upper limb muscles when subjects were perturbed while walking compared with undisturbed walking. This effect was less apparent when the arms were swinging freely. The results indicate that the strength of interlimb connections is influenced by the level of postural threat (i.e., the context of the behavior), thereby suggesting that these reflexes serve a functional link between the legs and arms during locomotion.

Modulation of Cutaneous Reflexes From the Foot During Gait in Parkinson's Disease

2010 ◽  
Vol 104 (1) ◽  
pp. 230-238 ◽  
Author(s):  
Jacques Duysens ◽  
Bart M. H. Van Wezel ◽  
Bouwien Smits-Engelsman
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Healthy Subjects ◽  
Biceps Femoris ◽  
Cutaneous Reflexes ◽  
Step Cycle ◽  
Reflex Responses ◽  
Cutaneous Reflex ◽  
Unsteady Gait ◽  
Fast Activation

Normal gait is characterized by a phase-dependent modulation of cutaneous reflexes. The role of the basal ganglia in regulating these reflexes is largely unknown. Therefore cutaneous reflex responses from the skin of the foot were studied during walking of patients with mild to moderate Parkinson's disease (PD). The reflex responses were elicited by stimulation of the sural nerve of the most affected leg. The responses were studied in the biceps femoris (BF) and tibialis anterior (TA) of both legs. The latencies, durations, and phase-dependent modulation patterns of the responses were mostly comparable with those observed in healthy subjects. However, on average the amplitude of the responses in the ipsilateral and contralateral BF was respectively 1.4- and 5-fold larger for the PD patients than that for the healthy subjects. This increase was mostly seen throughout the whole step cycle. However, in some PD patients the crossed BF responses were very large during the contralateral swing phase. In such cases the increase in crossed reflexes sometimes reflected premotoneuronal gating since it was not always due to increased background activation in that period. Fast activation of contralateral BF reflexes is known to occur in conjunction with ipsilateral perturbations when there is a threat to stability. It is concluded that cutanoeus reflexes are facilitated in PD but that some of the increase in reflexes in BF may be indirectly related to unsteady gait and to perceived instability.

Coordinated Interlimb Compensatory Responses to Electrical Stimulation of Cutaneous Nerves in the Hand and Foot During Walking

2003 ◽  
Vol 90 (5) ◽  
pp. 2850-2861 ◽  
Author(s):  
Carlos Haridas ◽  
E. Paul Zehr
Keyword(s):  
Electrical Stimulation ◽  
Motor Coordination ◽  
The Body ◽  
Emg Activity ◽  
Motor Tasks ◽  
Step Cycle ◽  
Reflex Responses ◽  
Cutaneous Reflex ◽  
Reflex Pathways ◽  
Stimulation Of

It has been shown that stimulation of cutaneous nerves innervating the hand (superficial radial, SR) and foot (superficial peroneal, SP) elicit widespread reflex responses in many muscles across the body. These interlimb reflex responses were suggested to be functionally relevant to assist in motor coordination between the arms and legs during motor tasks such as walking. The experiments described in this paper were conducted to test the hypothesis that interlimb reflexes were phase-dependently modulated and produced functional kinematic changes during locomotion. Subjects walked on a treadmill while electromyographic (EMG) activity was collected continuously from all four limbs, and kinematic recordings were made of angular changes across the ankle, knee, elbow, and shoulder joints. Cutaneous reflexes were evoked by delivering trains of electrical stimulation pseudorandomly to the SP nerve or SR nerves in separate trials. Reflexes were phase-averaged according to the time of occurrence in the step cycle, and phasic amplitudes and latencies were calculated. For both nerves, significant phase-dependent modulation (including reflex reversals) of interlimb cutaneous reflex responses was seen in most muscles studied. Both SR and SP nerve stimulation resulted in significant alteration in ankle joint kinematics. The results suggest coordinated and functionally relevant reflex pathways from the SP and SR nerves onto motoneurons innervating muscles in nonstimulated limbs during walking, thus extending observations from the cat to that of the bipedal human.

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)

Reflexes From the Superficial Peroneal Nerve During Walking in Stroke Subjects

1998 ◽  
Vol 79 (2) ◽  
pp. 848-858 ◽  
Author(s):  
E. P. Zehr ◽  
K. Fujita ◽  
R. B. Stein
Keyword(s):  
Peroneal Nerve ◽  
Vastus Lateralis ◽  
Biceps Femoris ◽  
Medial Gastrocnemius ◽  
Superficial Peroneal Nerve ◽  
Cutaneous Reflexes ◽  
Joint Angles ◽  
Step Cycle ◽  
Extensor Muscles ◽  
Neurologically Intact

Zehr, E. P., K. Fujita, and R. B. Stein. Reflexes from the superficial peroneal nerve during walking in stroke subjects. J. Neurophysiol. 79: 848–858, 1998. The function of ipsilateral cutaneous reflexes was studied with short trains of stimuli presented pseudorandomly to the superficial peroneal nerve (SP; innervates the top of the foot) during treadmill walking in neurologically intact (NI) subjects and subjects who had had a stroke. Ankle and knee joint angles together with electromyograms (EMG) of tibialis anterior (TA), soleus (SOL), medial gastrocnemius (MG), vastus lateralis (VL), and biceps femoris (BF) muscles were recorded. Net reflex EMG and kinematic responses to stimulation were quantified in each of the 16 parts of the step cycle and responses compared between the stroke and NI subjects. Stimulation strongly suppressed extensor muscles throughout stance in the stroke subjects. TA muscle showed a significant suppression during swing phase that was correlated with reduced ankle dorsiflexion in both stroke and NI subjects. BF reflexes were facilitatory during parts of swing and VL reflexes were suppressive throughout stance in the stroke subjects. There was a significant correlation between BF facilitation and knee flexion during swing, which was stronger in NI subjects. We conclude that only part of the stumble correction to foot dorsum electrical stimulation observed in NI subjects is maintained after stroke, and that new, suppressive responses are seen.

scholarly journals Selective bilateral activation of leg muscles after cutaneous nerve stimulation during backward walking

2012 ◽  
Vol 108 (7) ◽  
pp. 1933-1941 ◽  
Author(s):  
Wouter Hoogkamer ◽  
Firas Massaad ◽  
Karen Jansen ◽  
Sjoerd M. Bruijn ◽  
Jacques Duysens
Keyword(s):  
Nerve Stimulation ◽  
Sural Nerve ◽  
Center Of Mass ◽  
Biceps Femoris ◽  
Medial Gastrocnemius ◽  
Reflex Activity ◽  
Emg Activity ◽  
Cutaneous Reflexes ◽  
Backward Walking ◽  
Cutaneous Reflex

During human locomotion, cutaneous reflexes have been suggested to function to preserve balance. Specifically, cutaneous reflexes in the contralateral leg's muscles (with respect to the stimulus) were suggested to play an important role in maintaining stability during locomotor tasks where stability is threatened. We used backward walking (BW) as a paradigm to induce unstable gait and analyzed the cutaneous reflex activity in both ipsilateral and contralateral lower limb muscles after stimulation of the sural nerve at different phases of the gait cycle. In BW, the tibialis anterior (TA) reflex activity in the contralateral leg was markedly higher than TA background EMG activity during its stance phase. In addition, in BW a substantial reflex suppression was observed in the ipsilateral biceps femoris during the stance-swing transition in some participants, while for medial gastrocnemius the reflex activity was equal to background activity in both legs. To test whether the pronounced crossed responses in TA could be related to instability, the responses were correlated with measures of stability (short-term maximum Lyapunov exponents and step width). These measures were higher for BW compared with forward walking, indicating that BW is less stable. However, there was no significant correlation between these measures and the amplitude of the crossed TA responses in BW. It is therefore proposed that these crossed responses are related to an attempt to briefly slow down (TA decelerates the center of mass in the single-stance period) in the light of unexpected perturbations, such as provided by the sural nerve stimulation.

scholarly journals Cutaneous Reflexes During Human Gait: Electromyographic and Kinematic Responses to Electrical Stimulation

1997 ◽  
Vol 77 (6) ◽  
pp. 3311-3325 ◽  
Author(s):  
E. P. Zehr ◽  
T. Komiyama ◽  
R. B. Stein
Keyword(s):  
Electrical Stimulation ◽  
Nerve Stimulation ◽  
Tibial Nerve ◽  
Vastus Lateralis ◽  
Medial Gastrocnemius ◽  
Human Gait ◽  
Cutaneous Reflexes ◽  
Step Cycle ◽  
Tibial Nerve Stimulation ◽  
Corrective Response

Zehr, E. P., T. Komiyama, and R. B. Stein. Cutaneous reflexes during human gait: electromyographic and kinematic responses to electrical stimulation. J. Neurophysiol. 77: 3311–3325, 1997. The functions of ipsilateral cutaneous reflexes were studied with short trains of stimuli presented pseudorandomly to the superficial peroneal (SP) and tibial nerves during human gait. Electromyograms (EMGs) of tibialis anterior (TA), soleus, lateral and medial gastrocnemius, vastus lateralis (VL), and biceps femoris (BF) muscle were recorded, together with ankle and knee joint angles. Net reflex EMG responses were quantified in each of the 16 parts of the step cycle according to a recently developed technique. After SP nerve stimulation, TA muscle showed a significant suppression during swing phase that was highly correlated to ankle plantarflexion. BF and VL muscles were both excited throughout swing and significantly correlated to knee flexion during early swing. Tibial nerve stimulation caused dorsiflexion during late stance, but plantarflexion during late swing. We argue that SP nerve reflexes are indicative of a stumbling corrective response to nonnoxious electrical stimulation in humans. The correlated kinematic responses after tibial nerve stimulation may allow smooth movement of the swing leg so as to prevent tripping during swing and to assist placing and weight acceptance at the beginning of stance.

Monosynaptic and dorsal root reflexes during locomotion in normal and thalamic cats

1990 ◽  
Vol 63 (6) ◽  
pp. 1467-1476 ◽  
Author(s):  
S. H. Duenas ◽  
G. E. Loeb ◽  
W. B. Marks
Keyword(s):  
Dorsal Root ◽  
Nerve Fibers ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Emg Activity ◽  
Primary Afferent Depolarization ◽  
Step Cycle ◽  
Emg Amplitude ◽  
Group I ◽  
Stimulation Of

1. In normal and thalamic walking cats electrical stimulation of muscle nerves via chronically implanted electrodes produced electromyographic (EMG) and neurographic responses that were modulated in amplitude depending on the phase of the step cycle. These responses were examined for possible indications of effects of primary afferent depolarization (PAD) during stepping. 2. Monosynaptic reflexes (MSRs) produced by stimulating the lateral gastrocnemius (LG) and medial gastrocnemius (MG) nerves were recorded as EMGs in MG or LG muscles during treadmill locomotion in normal cats. These heteronymous MSR responses were greatest during the stance (extensor) phase. 3. In the same animals, after decerebration, similar modulation of the heteronymous ankle extensor MSRs occurred during spontaneous locomotion with the use of the same stimulus and recording sites. 4. In both normal and thalamic cats the amplitude of neurogram responses recorded from LG or MG nerve after stimulation of the other muscle nerve varied with phase of stepping but did not parallel the variations of the MSR measured as EMG amplitude in the same muscle. The nerve responses were largest during the flexion phase of the step cycle and had a calculated central latency of 0.6-1.0 ms. These are interpreted as arising from antidromic activity in large-caliber afferent nerve fibers (i.e., dorsal root reflexes). 5. Spontaneous antidromic activity in severed L7 dorsal rootlet fibers to triceps surae was observed in the thalamic cats during episodes of locomotion and was closely correlated with flexion phase EMG activity in semitendinosus, a bifunctional muscle. 6. In decerebrate cats, dorsal root reflexes (DRRs) in severed filaments of L4-L7 dorsal roots were produced by stimulation of saphenous and posterior tibial nerves. These DRRs were always smaller during locomotion than during rest and were smallest during the flexion phase. 7. The short-latency antidromic activity produced in muscle nerves by stimulating heteronymous muscle nerves thus appears to be a DRR produced in Group I terminal arborizations that are depolarized close to threshold during the flexion phase. Such PAD could account for changes in the MSR that do not always parallel the levels of recruitment of the motor pools as manifest by background EMG amplitude.

scholarly journals Association between Oxygen Consumption and Surface Electromyographic Amplitude and Its Variation within Individual Calf Muscles during Walking at Various Speeds

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1748
Author(s):  
Kohei Watanabe ◽  
Shideh Narouei
Keyword(s):  
Oxygen Consumption ◽  
Spatial Variation ◽  
Metabolic Response ◽  
Correlation Coefficients ◽  
Surface Emg ◽  
Medial Gastrocnemius ◽  
Whole Body ◽  
Young Males ◽  
Emg Amplitude ◽  
Calf Muscles

Surface electromyography (EMG) has been used to estimate muscle work and physiological burden of the whole body during human movements. However, there are spatial variations in surface EMG responses within individual muscles. The aim of this study was to investigate the relation between oxygen consumption and surface EMG responses of lower leg muscles during walking at various speeds and to quantify its spatial variation within an individual muscle. Nine young males walked on a treadmill at four speeds: preferred minus 1 km/h, preferred, preferred plus 1 km/h, and preferred plus 2 km/h, and the metabolic response was measured based on the expired gas. High-density surface EMG of the tibialis anterior (TA), medial gastrocnemius (MG), lateral gastrocnemius, and soleus muscles was performed using 64 two-dimensional electrode grids. Correlation coefficients between oxygen consumption and the surface EMG amplitude were calculated across the gait speeds for each channel in the electrode grid and for individual muscles. Mean correlation coefficients across electrodes were 0.69–0.87 for the four individual muscles, and the spatial variation of correlation between the surface EMG amplitude and oxygen consumption within an electrode grid was significantly greater in MG muscle than in TA muscle (Quartile deviations: 0.24 for MG and 0.02 for TA, p < 0.05). These results suggest that the physiological burden of the whole body during gait at various speeds can be estimated from the surface EMG amplitude of calf muscles, but we need to note its spatial distribution within the MG muscle.

Structure and Function of the Lateral Giant Neurone of the Primitive Crustacean Anaspides Tasmaniae

1979 ◽  
Vol 78 (1) ◽  
pp. 121-136
Author(s):  
GERALD E. SILVEY ◽  
IAN S. WILSON
Keyword(s):  
Action Potentials ◽  
Tactile Stimulation ◽  
Large Diameter ◽  
Whole Body ◽  
Giant Fibre ◽  
Single Action ◽  
Giant Neurone ◽  
And Function ◽  
Thoracic And Abdominal ◽  
Stimulation Of

The syncarid crustacean Anaspides tasmaniae rapidly flexes its free thoracic and abdominal segments in response to tactile stimulation of its body. This response decrements but recovers in slightly more than one hour. The fast flexion is evoked by single action potentials in the lateral of two large diameter fibres (40 μm) which lie on either side of the cord. The lateral giant fibre is made up of fused axons of 11 neurones, one in each of the last 5 thoracic and 6 abdominal ganglia. The soma of each neurone lies contralateral to the axon. Its neurite crosses that of its counterpart in the commissure and gives out dendrites into the neuropile of each hemiganglion. The lateral giant neurone receives input from the whole body but fires in response only to input from the fourth thoracic segment posteriorly. Both fibres respond with tactile stimulation of only one side. Since neither current nor action potentials spread from one fibre to the other, afferents must synapse with both giant neurones. The close morphological and physiological similarities of the lateral giant neurone in Anaspides to that in the crayfish (Eucarida) suggest that the lateral giant system arose in the ancestor common to syncarids and eucarids, prior to the Carboniferous.

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