Enhanced somatosensory feedback modulates cutaneous reflexes in arm muscles during self-triggered or prolonged stimulation

While the effects of sensory feedback on bimanual tasks have been studied extensively at two ends of the motor control hierarchy, the cortical and behavioral levels, much less is known about how it affects the intermediate levels, including neural control of homologous muscle groups. We investigated the effects of somatosensory input on the neural coupling between homologous arm muscles during bimanual tasks. Twelve subjects performed symmetric elbow flexion/extension tasks under different types of sensory feedback. The first two types involve visual feedback, with one imposing stricter force symmetry than the other. The third incorporated somatosensory feedback via a balancing apparatus that forced the two limbs to produce equal force levels. Although the force error did not differ between feedback conditions, the somatosensory feedback significantly increased temporal coupling of bilateral force production, indicated by a high correlation between left/right force profiles ( P < 0.001). More importantly, intermuscular coherence between biceps brachii muscles was significantly higher with somatosensory feedback than others ( P = 0.001). Coherence values also significantly differed between tasks (flexion/extension). Notably, whereas feedback type mainly modulated coherence in the α- and γ-bands, task type only affected β-band coherence. Similar feedback effects were observed for triceps brachii muscles, but there was also a strong phase effect on the coherence values ( P < 0.001) that could have diluted feedback effects. These results suggest that somatosensory feedback can significantly increase neural coupling between homologous muscles. Additionally, the between-task difference in β-band coherence may reflect different neural control strategies for the elbow flexor and extensor muscles. NEW & NOTEWORTHY This study investigated the effects of somatosensory feedback during bimanual tasks on the neural coupling between arm muscles, which remains largely unexplored. Somatosensory feedback using a balancing apparatus, compared with visual feedback, significantly increased neural coupling between homologous muscles (indicated by intermuscular coherence values) and improved temporal correlation of bilateral force production. Notably, feedback type modulated coherence in the α- and γ-bands (more subcortical pathways), whereas task type mainly affected β-band coherence (corticospinal pathway).

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

Journal of Neurophysiology ◽

10.1152/jn.00746.2006 ◽

2006 ◽

Vol 96 (6) ◽

pp. 3096-3103 ◽

Cited By ~ 22

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.

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Inhibition and Facilitation of the Spinal Locomotor Central Pattern Generator and Reflex Circuits by Somatosensory Feedback From the Lumbar and Perineal Regions After Spinal Cord Injury

Frontiers in Neuroscience ◽

10.3389/fnins.2021.720542 ◽

2021 ◽

Vol 15 ◽

Author(s):

Angèle N. Merlet ◽

Jonathan Harnie ◽

Alain Frigon

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Central Pattern Generator ◽

Pattern Generator ◽

Lumbar Region ◽

Cutaneous Reflexes ◽

Somatosensory Feedback ◽

Cord Injury ◽

Perineal Region ◽

Complete Spinal Cord Injury

Somatosensory feedback from peripheral receptors dynamically interacts with networks located in the spinal cord and brain to control mammalian locomotion. Although somatosensory feedback from the limbs plays a major role in regulating locomotor output, those from other regions, such as lumbar and perineal areas also shape locomotor activity. In mammals with a complete spinal cord injury, inputs from the lumbar region powerfully inhibit hindlimb locomotion, while those from the perineal region facilitate it. Our recent work in cats with a complete spinal cord injury shows that they also have opposite effects on cutaneous reflexes from the foot. Lumbar inputs increase the gain of reflexes while those from the perineal region decrease it. The purpose of this review is to discuss how somatosensory feedback from the lumbar and perineal regions modulate the spinal locomotor central pattern generator and reflex circuits after spinal cord injury and the possible mechanisms involved. We also discuss how spinal cord injury can lead to a loss of functional specificity through the abnormal activation of functions by somatosensory feedback, such as the concurrent activation of locomotion and micturition. Lastly, we discuss the potential functions of somatosensory feedback from the lumbar and perineal regions and their potential for promoting motor recovery after spinal cord injury.

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Reflex Responses in Upper Limb Muscles to Cutaneous Stimuli

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques ◽

10.1017/s0317167100048174 ◽

1993 ◽

Vol 20 (04) ◽

pp. 271-278 ◽

Cited By ~ 30

Author(s):

R. Chen

Keyword(s):

Stimulus Intensity ◽

Upper Limb ◽

Healthy Subjects ◽

Voluntary Contraction ◽

Cutaneous Reflexes ◽

Focal Lesions ◽

Normal Ranges ◽

Conduction Velocities ◽

Limb Muscles ◽

Biphasic Responses

ABSTRACT:Cutaneous reflexes in the upper limb were elicited by stimulating digital nerves and recorded by averaging rectified EMG from proximal and distal upper limb muscles during voluntary contraction. Distal muscles often showed a triphasic response: an inhibition with onset about 50 ms (Il) followed by a facilitation with onset about 60 ms (E2) followed by another inhibition with onset about 80 ms (12). Proximal muscles generally showed biphasic responses beginning with facilitation or inhibition with onset at about 40 ms. Normal ranges for the amplitude of these components were established from recordings on 22 arms of 11 healthy subjects. An attempt was made to determine the alterent fibers responsible for the various components by varying the stimulus intensity, by causing ischemic block of larger fibers and by estimating the afferent conduction velocities. The central pathways mediating these reflexes were examined by estimating central delays and by studying patients with focal lesions

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The Movement- and Load-Dependent Differences in the EMG Patterns of the Human Arm Muscles during Two-Joint Movements (A Preliminary Study)

Frontiers in Physiology ◽

10.3389/fphys.2016.00218 ◽

2016 ◽

Vol 7 ◽

Cited By ~ 8

Author(s):

Tomasz Tomiak ◽

Tetiana I. Abramovych ◽

Andriy V. Gorkovenko ◽

Inna V. Vereshchaka ◽

Viktor S. Mishchenko ◽

...

Keyword(s):

Human Arm ◽

Arm Muscles ◽

Preliminary Study ◽

Emg Patterns

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Task-Specific Somatosensory Feedback via Cortical Stimulation in Humans

IEEE Transactions on Haptics ◽

10.1109/toh.2016.2591952 ◽

2016 ◽

Vol 9 (4) ◽

pp. 515-522 ◽

Cited By ~ 22

Author(s):

Jeneva A. Cronin ◽

Jing Wu ◽

Kelly L. Collins ◽

Devapratim Sarma ◽

Rajesh P. N. Rao ◽

...

Keyword(s):

Cortical Stimulation ◽

Somatosensory Feedback

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Sensory Preference in Speech Production Revealed by Simultaneous Alteration of Auditory and Somatosensory Feedback

Journal of Neuroscience ◽

10.1523/jneurosci.0404-12.2012 ◽

2012 ◽

Vol 32 (27) ◽

pp. 9351-9358 ◽

Cited By ~ 110

Author(s):

D. R. Lametti ◽

S. M. Nasir ◽

D. J. Ostry

Keyword(s):

Speech Production ◽

Somatosensory Feedback ◽

Sensory Preference

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Probability-Based Prediction of Activity in Multiple Arm Muscles: Implications for Functional Electrical Stimulation

Journal of Neurophysiology ◽

10.1152/jn.00956.2007 ◽

2008 ◽

Vol 100 (1) ◽

pp. 482-494 ◽

Cited By ~ 9

Author(s):

Chad V. Anderson ◽

Andrew J. Fuglevand

Keyword(s):

Electrical Stimulation ◽

Functional Electrical Stimulation ◽

Muscle Activity ◽

Probability Distributions ◽

Probabilistic Methods ◽

Muscle Stimulation ◽

Implanted Electrodes ◽

Motor Behaviors ◽

Wide Range ◽

Arm Muscles

Functional electrical stimulation (FES) involves artificial activation of muscles with implanted electrodes to restore motor function in paralyzed individuals. The range of motor behaviors that can be generated by FES, however, is limited to a small set of preprogrammed movements such as hand grasp and release. A broader range of movements has not been implemented because of the substantial difficulty associated with identifying the patterns of muscle stimulation needed to elicit specified movements. To overcome this limitation in controlling FES systems, we used probabilistic methods to estimate the levels of muscle activity in the human arm during a wide range of free movements based on kinematic information of the upper limb. Conditional probability distributions were generated based on hand kinematics and associated surface electromyographic (EMG) signals from 12 arm muscles recorded during a training task involving random movements of the arm in one subject. These distributions were then used to predict in four other subjects the patterns of muscle activity associated with eight different movement tasks. On average, about 40% of the variance in the actual EMG signals could be accounted for in the predicted EMG signals. These results suggest that probabilistic methods ultimately might be used to predict the patterns of muscle stimulation needed to produce a wide array of desired movements in paralyzed individuals with FES.

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