Mechanical analysis of heterogenic inhibition between soleus muscle and the pretibial flexors in the cat

1991 ◽  
Vol 66 (4) ◽  
pp. 1139-1155 ◽  
Author(s):  
T. R. Nichols ◽  
D. Koffler-Smulevitz
Keyword(s):  
Stretch Reflex ◽  
Metatarsophalangeal Joint ◽  
Reciprocal Inhibition ◽  
Mechanical Analysis ◽  
Initial State ◽  
Stretch Reflexes ◽  
Decerebrate Cat ◽  
Intravenous Injections ◽  
Activation Level ◽  
Length Changes

1. The role of proprioceptive pathways linking the direct antagonists soleus (S) and tibialis anterior (TA) muscles in governing the mechanical properties of the ankle joint were studied in the decerebrate cat. Actions of these heterogenic pathways were compared with those between S and extensor digitorum longus (EDL), a muscle that also acts at the metatarsophalangeal joint. These neurally mediated interactions between S and either TA or EDL were studied by applying controlled length changes to the isolated tendons of pairs of these muscles and recording the resulting changes in force. The muscles were activated with the use of electrically evoked crossed-extension reflexes, flexion reflexes, and brain stem stimulation. 2. Heterogenic inhibition from TA or EDL onto S was well developed whether S was initially quiescent or activated by a crossed-extension reflex. The inhibition persisted for the duration of the stretch of TA or EDL. During a crossed-extension reflex, TA did not generate background force, but brief stretch reflexes could be obtained. During flexion reflexes, stretch reflexes in S were usually abolished, and heterogenic inhibition from S to TA was weak or absent. 3. The strength of the heterogenic inhibition onto S was dependent on the initial length and activation level of TA and EDL. Changes in flexor length or activation level per se did not alter the background force or strength of the stretch reflex in S. Even taking into account the variation of strength of inhibition with the initial state of the muscle of origin, the strength of the inhibition was stronger from TA to S than the other way around. 4. The contributions of heterogenic inhibition from TA and EDL to S were independent in the sense that these components summed linearly with each other and with the autogenic reflex in S. In addition, the magnitude of the inhibition from TA to S was proportional to the amplitude of stretch for low to intermediate levels of initial force in S. The inhibition appeared to affect the mechanical responses of S essentially as rapidly as the stretch reflex in this muscle. 5. The heterogenic inhibition from TA to S was reduced or abolished by intravenous injections of strychnine but unaffected by injections of picrotoxin or bicuculline. These results, together with the observation that the inhibition sums linearly with the stretch reflex, suggest that the mechanism of this heterogenic inhibition is glycinergic and postsynaptic and, therefore, may include Ia-disynaptic reciprocal inhibition.(ABSTRACT TRUNCATED AT 400 WORDS)

The effects of cold-induced muscle spindle secondary activity on monosynaptic and stretch reflexes in the decerebrate cat

1979 ◽  
Vol 57 (6) ◽  
pp. 606-614 ◽  
Author(s):  
C. E. Chapman ◽  
W. J. Michalski ◽  
J. J. Séguin
Keyword(s):  
Muscle Spindle ◽  
Stretch Reflex ◽  
Synergistic Effects ◽  
Medial Gastrocnemius ◽  
Monosynaptic Reflex ◽  
Lateral Gastrocnemius ◽  
Stretch Reflexes ◽  
Decerebrate Cat ◽  
Muscle Cooling ◽  
Decerebrate Cats

The effects of muscle spindle secondary ending activity on the stretch reflex were studied in unanesthetized decerebrate cats. Activation of secondary endings was accomplished by reducing the muscle temperature. This has been shown to cause a sustained asynchronous discharge from secondary endings. Cooling of the medial gastrocnemius or lateral gastrocnemius–soleus muscles caused an increase in the phasic and tonic components of their stretch reflexes. Cooling of the relaxed medial gastrocnemius muscle caused similar increases in the components of the stretch reflex of the synergistic lateral gastrocnemius–soleus muscle and an increase in its monosynaptic reflex. It was concluded that the facilitatory autogenetic and synergistic effects of muscle cooling on the stretch and monosynaptic reflexes were brought about by activity in group II afferents from muscle spindle secondary endings and could not be ascribed to any other type of muscle receptor. These results support the concept of an excitatory role for the secondary endings of the muscle spindle in the stretch reflex of the decerebrate cat.

scholarly journals Reciprocal inhibition during the tonic stretch reflex in the decerebrate cat.

1978 ◽  
Vol 284 (1) ◽  
pp. 345-369 ◽  
Author(s):  
T C Fu ◽  
H Hultborn ◽  
R Larsson ◽  
A Lundberg
Keyword(s):  
Stretch Reflex ◽  
Reciprocal Inhibition ◽  
Decerebrate Cat

Statistical Considerations When Assessing Short Latency Stretch Reflexes in the Human Soleus Muscle

Motor Control ◽  
2015 ◽  
Vol 19 (4) ◽  
pp. 253-270 ◽  
Author(s):  
Asger Roer Pedersen ◽  
Peter William Stubbs ◽  
Jørgen Feldbæk Nielsen
Keyword(s):  
Ankle Joint ◽  
Soleus Muscle ◽  
Stretch Reflex ◽  
Short Latency ◽  
Response Magnitude ◽  
Variance Heterogeneity ◽  
Stretch Reflexes ◽  
Response Characteristics ◽  
Normally Distributed

The aim was to investigate trial-by-trial response characteristics in the short-latency stretch reflex (SSR). Fourteen dorsiflexion stretches were applied to the ankle joint with a precontracted soleus muscle on 2 days. The magnitude and variability of trial-by-trial responses of the SSR were assessed. The SSR was log-normally distributed and variance heterogeneous between subjects. For some subjects, the magnitude and variance differed between days and stretches. As velocity increased, variance heterogeneity tended to decrease and response magnitude increased. The current study demonstrates the need to assess trial-by-trial response characteristics and not averaged curves. Moreover, it provides an analysis of SSR characteristics accounting for log-normally distributed and variance heterogeneous trial-by-trial responses.

Measuring poststroke spasticity

2000 ◽  
Vol 10 (1) ◽  
pp. 69-74 ◽  
Author(s):  
J. M. Gregson ◽  
A. K. Sharma
Keyword(s):  
Normal State ◽  
Stretch Reflex ◽  
Muscle Activation ◽  
Muscle Tone ◽  
Clinical Syndrome ◽  
Motor Disorder ◽  
Muscle Forces ◽  
Joint Movement ◽  
Stretch Reflexes ◽  
Reflex Action

What is spasticity?Spasticity is a well-recognized and potentially important clinical syndrome comprising inappropriate and involuntary high muscle tone. It has been variably defined, with debate still ongoing. Currently, the most widely accepted definition is that of Lance, stating that spasticity is ‘a motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes (muscle tone) with exaggerated tendon jerks, resulting from hyper-excitability of the stretch reflex.’ Unfortunately, even this description does not fully encompass the multifactorial nature of spasticity, since resistance to movement, even in the normal state, is subject to varied contributors. These include patient volition, inertia, visco-elastic muscle forces and range of joint movement, as well as true muscle activation secondary to reflex action. In the real clinical world, it is often not possible to distinguish which of these features is/are dominant. Furthermore, spastic muscle undergoes physiopathological, rheologic change with stiffness, atrophy, fibrosis and finally contracture.

Effects of contraction intensity on muscle fascicle and stretch reflex behavior in the human triceps surae

2008 ◽  
Vol 105 (1) ◽  
pp. 226-232 ◽  
Author(s):  
Neil J. Cronin ◽  
Jussi Peltonen ◽  
Masaki Ishikawa ◽  
Paavo V. Komi ◽  
Janne Avela ◽  
...  
Keyword(s):  
Stretch Reflex ◽  
Force Production ◽  
Voluntary Contraction ◽  
Short Latency ◽  
Afferent Feedback ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Stretch Reflexes ◽  
Muscle Fascicle ◽  
Human Triceps Surae

The aims of this study were to examine changes in the distribution of a stretch to the muscle fascicles with changes in contraction intensity in the human triceps surae and to relate fascicle stretch responses to short-latency stretch reflex behavior. Thirteen healthy subjects were seated in an ankle ergometer, and dorsiflexion stretches (8°; 250°/s) were applied to the triceps surae at different moment levels (0–100% of maximal voluntary contraction). Surface EMG was recorded in the medial gastrocnemius, soleus, and tibialis anterior muscles, and ultrasound was used to measure medial gastrocnemius and soleus fascicle lengths. At low forces, reflex amplitudes increased despite a lack of change or even a decrease in fascicle stretch velocities. At high forces, lower fascicle stretch velocities coincided with smaller stretch reflexes. The results revealed a decline in fascicle stretch velocity of over 50% between passive conditions and maximal force levels in the major muscles of the triceps surae. This is likely to be an important factor related to the decline in stretch reflex amplitudes at high forces. Because short-latency stretch reflexes contribute to force production and stiffness regulation of human muscle fibers, a reduction in afferent feedback from muscle spindles could decrease the efficacy of human movements involving the triceps surae, particularly where high force production is required.

scholarly journals Visually-updated hand state estimates modulate the proprioceptive reflex independently of motor task requirements

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Sho Ito ◽  
Hiroaki Gomi
Keyword(s):  
Stretch Reflex ◽  
Muscle Activation ◽  
Motor Task ◽  
Proprioceptive Information ◽  
Motor Tasks ◽  
Stretch Reflexes ◽  
Motor Mapping ◽  
Task Requirements ◽  
Multimodal Information ◽  
Proprioceptive Reflex

Fast signaling from vision and proprioception to muscle activation plays essential roles in quickly correcting movement. Though many studies have demonstrated modulation of the quick sensorimotor responses as depending on context in each modality, the contribution of multimodal information has not been established. Here, we examined whether state estimates contributing to stretch reflexes are represented solely by proprioceptive information or by multimodal information. Unlike previous studies, we newly found a significant stretch-reflex attenuation by the distortion and elimination of visual-feedback without any change in motor tasks. Furthermore, the stretch-reflex amplitude reduced with increasing elimination durations which would degrade state estimates. By contrast, even though a distortion was introduced in the target-motor-mapping, the stretch reflex was not simultaneously attenuated with visuomotor reflex. Our results therefore indicate that the observed stretch-reflex attenuation is specifically ascribed to uncertainty increase in estimating hand states, suggesting multimodal contributions to the generation of stretch reflexes.

Mechanical and electromyographic analysis of reciprocal inhibition at the human ankle joint

1995 ◽  
Vol 74 (2) ◽  
pp. 849-855 ◽  
Author(s):  
T. Sinkjaer ◽  
J. Nielsen ◽  
E. Toft
Keyword(s):  
Ankle Joint ◽  
Stretch Reflex ◽  
Plantar Flexion ◽  
Joint Stiffness ◽  
Common Peroneal Nerve ◽  
Reciprocal Inhibition ◽  
Mechanical Effect ◽  
Voluntary Contraction ◽  
Plantar Flexors ◽  
Before And After

1. The purpose of the present study is to investigate how reciprocal inhibition influences the mechanical and electromyographic (EMG) properties of the ankle plantar flexors in humans during a voluntary contraction. 2. At different levels of maintained plantar flexion contractions ranging from 0 to 20 Nm, the size of the soleus EMG stretch reflex and the ankle joint stiffness (ration between the torque increment and the amplitude of the stretch) were measured in response to an imposed dorsiflexion. At matched plantar flexion contraction levels, stretch responses were compared before and after reversible block of the common peroneal nerve (CPN). Stretch responses were also measured during an attempted voluntary fictive dorsiflexion after CPN block. 3. In the preactivated soleus muscles, the phasic EMG response to stretch consisted of two peaks labeled M1 and M2. After CPN block, the M1 short-latency stretch reflex on average increased by 25 +/- 5.7%, mean +/- SD (P < 0.001), and the M2 stretch reflex increased on average by 29 +/- 13.0% (P = 0.002). 4. The total stiffness of the ankle joint during a stretch is the sum of the nonreflex and the reflex mediated stiffness. The total stiffness after CPN block increased on average by 13 +/- 2.7% (P = 0.002) and the estimated reflex stiffness by 33 +/- 6.5% (P < 0.001). 5. When the subjects were asked to make a strong dorsiflexion after CPN block, the soleus stretch reflex was depressed to the extent that the reflex mediated mechanical effect around the ankle joint was abolished.(ABSTRACT TRUNCATED AT 250 WORDS)

Interaction of Vestibular and Proprioceptive Reflexes in the Decerebrate Cat

1956 ◽  
Vol 185 (3) ◽  
pp. 607-613 ◽  
Author(s):  
Werner P. Koella ◽  
Hiroyuki Nakao ◽  
Robert L. Evans ◽  
Jun Wada
Keyword(s):  
Stretch Reflex ◽  
Muscle Spindles ◽  
Longitudinal Axis ◽  
Strain Gauges ◽  
Vestibular Apparatus ◽  
Triceps Brachii ◽  
Decerebrate Cat ◽  
Proprioceptive Reflexes ◽  
The Difference ◽  
Decerebrate Cats

The quantitative interrelation between stretch, tension and position in space was studied in decerebrate cats. The tension produced by the isolated M. triceps brachii was recorded by means of strain gauges. It was found that the tension increment, produced by a particular stretch, increases as the preparation is turned from the prone to the supine position around its longitudinal axis. The proportion between the tensions produced by a series of two or more different stretches, however, stays constant under these conditions. It was shown, furthermore, that the effect of a change in position upon the degree of rigidity—i.e., the difference between the tensions in the prone and in the supine positions—is the greater the greater the initial stretch. A quantitative analysis of the results disclosed that the vestibular factor and the proprioceptive factor are related in a multiplicative manner. These experiments show that the vestibular apparatus and the muscle spindles exert their influence not in an isolated and independent, but a quantitatively interdependent manner. The results of the present work together with the findings of other authors (Granit) give strength to the argument that the vestibular apparatus controls the stretch reflex activity in an indirect manner, i.e., over the ‘by-pass’ of the gamma-efferents.

scholarly journals Interactions Between Limb and Environmental Mechanics Influence Stretch Reflex Sensitivity in the Human Arm

2010 ◽  
Vol 103 (1) ◽  
pp. 429-440 ◽  
Author(s):  
Matthew A. Krutky ◽  
Vengateswaran J. Ravichandran ◽  
Randy D. Trumbower ◽  
Eric J. Perreault
Keyword(s):  
Mechanical Properties ◽  
Tool Use ◽  
Stretch Reflex ◽  
Negative Stiffness ◽  
Reflex Modulation ◽  
Stretch Reflexes ◽  
Human Arm ◽  
Environmental Instability ◽  
Increased Sensitivity ◽  
Endpoint Stiffness

Stretch reflexes contribute to arm impedance and longer-latency stretch reflexes exhibit increased sensitivity during interactions with compliant or unstable environments. This increased sensitivity is consistent with a regulation of arm impedance to compensate for decreased stability of the environment, but the specificity of this modulation has yet to be investigated. Many tasks, such as tool use, compromise arm stability along specific directions, and stretch reflexes tuned to those directions could present an efficient mechanism for regulating arm impedance in a task-appropriate manner. To be effective, such tuning should adapt not only to the mechanical properties of the environment but to those properties in relation to the arm, which also has directionally specific mechanical properties. The purpose of this study was to investigate the specificity of stretch reflex modulation during interactions with mechanical environments that challenge arm stability. The tested environments were unstable, having the characteristics of a negative stiffness spring. These were either aligned or orthogonal to the direction of maximal endpoint stiffness for each subject. Our results demonstrate preferential increases in reflexes, elicited within 50–100 ms of perturbation onset, to perturbations applied specifically along the direction of the destabilizing environments. This increase occurred only when the magnitude of the environmental instability exceeded endpoint stiffness along the same direction. These results are consistent with task-specific reflex modulation tuned to the mechanical properties of the environment relative to those of the human arm. They demonstrate a highly adaptable, involuntary mechanism that may be used to modulate limb impedance along specific directions.

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