Changes in the excitability of soleus muscle short latency stretch reflexes during human hopping after 4 weeks of hopping training

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.

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Excessive short-latency stretch reflexes in the calf muscles do not cause postural instability in patients with hereditary spastic paraplegia

Clinical Neurophysiology ◽

10.1016/j.clinph.2019.05.005 ◽

2019 ◽

Vol 130 (8) ◽

pp. 1188-1195

Author(s):

B.J.H. van Lith ◽

M. de Niet ◽

B.P.C. van de Warrenburg ◽

A.C. Geurts ◽

V. Weerdesteyn

Keyword(s):

Hereditary Spastic Paraplegia ◽

Postural Instability ◽

Short Latency ◽

Spastic Paraplegia ◽

Stretch Reflexes ◽

Calf Muscles

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Phase-Dependent Inhibition of H-Reflexes During Walking in Humans Is Independent of Reduction in Knee Angular Velocity

Journal of Neurophysiology ◽

10.1152/jn.1999.82.2.747 ◽

1999 ◽

Vol 82 (2) ◽

pp. 747-753 ◽

Cited By ~ 25

Author(s):

M. Garrett ◽

T. Kerr ◽

B. Caulfield

Keyword(s):

Angular Velocity ◽

Knee Joint ◽

Soleus Muscle ◽

Normal Subjects ◽

Afferent Input ◽

H Reflex ◽

Short Latency ◽

Reflex Modulation ◽

Reflex Responses ◽

Knee Movement

The purpose of this investigation was to investigate whether reduction in impulses arising from stretch of the quadriceps by restricting rapid knee flexion in early swing would affect inhibition of the H-reflex during swing. The contribution of afferent input arising from knee angular velocity to phase-dependent modulation of short-latency responses in the soleus was studied by simultaneously measuring joint velocity and soleus H-reflex responses at midstance and midswing phases of treadmill walking in 15 normal subjects. Stimulus strength was varied so that both maximal M and H waves were identified in each subject at midswing and midstance with the knee unrestricted (UK) and with knee movement restricted (RK), using a full leg bivalved cast to immobilize the knee joint. All subjects exhibited short-latency reflex responses in the soleus muscle. The H/M ratio at midswing was significantly reduced compared with midstance under both UK and RK walking conditions ( P < 0.0001). When compared with UK walking, knee joint angular velocity during RK walking was significantly reduced at midswing ( P < 0.001) and midstance ( P < 0.005) compared with UK. There were, however, no significant differences in H/M ratios at midswing and midstance between UK and RK walking tests. Inhibition of the H-reflex in the soleus muscle during swing was not affected by significant reduction in knee angular velocity. These results indicate that the sensory input from changes in angular velocity at the knee does not lay the inhibitory foundation of phase-related reflex modulation in the ankle extensors during walking as suggested by Brooke and colleagues.

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Widespread short-latency stretch reflexes and their modulation during stumbling over obstacles

Brain Research ◽

10.1016/s0006-8993(98)01198-6 ◽

1999 ◽

Vol 816 (2) ◽

pp. 480-486 ◽

Cited By ~ 56

Author(s):

A.M. Schillings ◽

B.M.H. Van Wezel ◽

TH. Mulder ◽

J. Duysens

Keyword(s):

Short Latency ◽

Stretch Reflexes

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

Journal of Applied Physiology ◽

10.1152/japplphysiol.90432.2008 ◽

2008 ◽

Vol 105 (1) ◽

pp. 226-232 ◽

Cited By ~ 27

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.

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Sympathetic outflow enhances the stretch reflex response in the relaxed soleus muscle in humans

Journal of Applied Physiology ◽

10.1152/japplphysiol.00955.2004 ◽

2005 ◽

Vol 98 (4) ◽

pp. 1366-1370 ◽

Cited By ~ 16

Author(s):

Nis Hjortskov ◽

Jørgen Skotte ◽

Christian Hye-Knudsen ◽

Nils Fallentin

Keyword(s):

Soleus Muscle ◽

Stretch Reflex ◽

Mental Arithmetic ◽

Muscle Spindles ◽

Short Latency ◽

Reflex Response ◽

Sympathetic Outflow ◽

Direct Influence ◽

Handgrip Exercise ◽

Sympathetic Nervous

Animal experiments suggest that an increase in sympathetic outflow can depress muscle spindle sensitivity and thus modulate the stretch reflex response. The results are, however, controversial, and human studies have failed to demonstrate a direct influence of the sympathetic nervous system on the sensitivity of muscle spindles. We studied the effect of increased sympathetic outflow on the short-latency stretch reflex in the soleus muscle evoked by tapping the Achilles tendon. Nine subjects performed three maneuvers causing a sustained activation of sympathetic outflow to the leg: 3 min of static handgrip exercise at 30% of maximal voluntary contraction, followed by 3 min of posthandgrip ischemia, and finally during a 3-min mental arithmetic task. Electromyography was measured from the soleus muscle with bipolar surface electrodes during the Achilles tendon tapping, and beat-to-beat changes in heart rate and mean arterial blood pressure were monitored continuously. Mean arterial pressure was significantly elevated during all three maneuvers, whereas heart rate was significantly elevated during static handgrip exercise and mental arithmetic but not during posthandgrip ischemia. The peak-to-peak amplitude of the short-latency stretch reflex was significantly increased during mental arithmetic ( P < 0.05), static handgrip exercise ( P < 0.001), and posthandgrip ischemia ( P < 0.005). When expressed in percent change from rest, the mean peak-to-peak amplitude increased by 111 (SD 100)% during mental arithmetic, by 160 (SD 103)% during static handgrip exercise, and by 90 (SD 67)% during posthandgrip ischemia. The study clearly indicates a facilitation of the short-latency stretch reflex during increased sympathetic outflow. We note that the enhanced stretch reflex responses observed in relaxed muscles in the absence of skeletomotor activity support the idea that the sympathetic nervous system can exert a direct influence on the human muscle spindles.

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Modulation of short latency stretch reflexes during human hopping

Acta Physiologica Scandinavica ◽

10.1046/j.1365-201x.1998.00351.x ◽

1998 ◽

Vol 163 (2) ◽

pp. 181-194 ◽

Cited By ~ 64

Author(s):

VOIGT ◽

DYHRE‐POULSEN ◽

SIMONSEN

Keyword(s):

Short Latency ◽

Stretch Reflexes

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Training-Specific Adaptations of H- and Stretch Reflexes in Human Soleus Muscle

Journal of Motor Behavior ◽

10.3200/jmbr.39.1.68-78 ◽

2007 ◽

Vol 39 (1) ◽

pp. 68-78 ◽

Cited By ~ 63

Author(s):

Markus Gruber ◽

Wolfgang Taube ◽

Albert Gollhofer ◽

Sandra Beck ◽

Florian Amtage ◽

...

Keyword(s):

Soleus Muscle ◽

Stretch Reflexes

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Alterations in group Ia projections to motoneurons following spinal lesions in humans

Journal of Neurophysiology ◽

10.1152/jn.1990.64.2.637 ◽

1990 ◽

Vol 64 (2) ◽

pp. 637-647 ◽

Cited By ~ 40

Author(s):

A. Mailis ◽

P. Ashby

Keyword(s):

Spinal Cord ◽

Normal Subjects ◽

Muscle Afferents ◽

Short Latency ◽

Spinal Cord Lesions ◽

Stretch Reflexes ◽

Spinal Lesions ◽

Group I ◽

Ia Epsp ◽

Stimulation Of

1. The hypothesis that the exaggerated tendon jerks and stretch reflexes that follow chronic spinal cord lesions in humans result from alterations in transmission from group I muscle afferents to motoneurons was tested by making observations on nine normal subjects and 25 patients with spinal cord lesions. All the patients had increased tendon jerks, one-third of them had both increased tendon jerks and increased, velocity-dependent stretch reflexes (i.e.g spasticity). 2. Changes in the firing probability of single, voluntary-activated soleus or tibialis anterior motor units during stimulation of the muscle nerve below the threshold of the alpha-motoneuron axons were used to derive the characteristics of the postsynaptic potentials produced by group I volleys in single motoneurons. Paired stimuli were used to test how multiple volleys in group I muscle afferents were transmitted to motoneurons. 3. Stimulation of the posterior tibial nerve produced a short-latency period of increased firing probability representing the homonymous composite Ia excitatory postsynaptic potential (EPSP) in all soleus motoneurons tested. There was no detectable alteration in the magnitude, duration, or profile of the short-latency facilitation in the patients with spinal lesions when compared with normal subjects. 4. In patients with traumatic spinal cord lesions less than 8 wk in duration the magnitude of the facilitation representing the composite Ia EPSP was significantly larger than normal, although only one out of the four patients in this group had spasticity. 5. In the patients with the greatest spasticity, group I volleys produced a second period of facilitation 11-15 ms after the facilitation representing the composite Ia EPSP. This is presumed to represent enhanced transmission through polysynaptic pathways from group I afferents to motoneurons. 6. In normal subjects the facilitation of motoneurons produced by the second of two group I volleys is greater 5 and 10 ms after the first volley and less 20, 30, and 50 ms after the first volley. These changes involve at least two factors: 1) changes in excitability of peripheral nerves and 2) changes in transmission at the Ia-motoneuron synapse. 7. In patients with spinal lesions the facilitation produced by the second of two muscle-afferent volleys was less depressed at the 30-ms interstimulus interval. 8. Thus two separate abnormalities have been uncovered in human subjects with chronic spinal lesions: 1) a change in the transmission of multiple volleys from muscle afferents to motoneurons and 2) an increase in transmission through polysynaptic pathways from Ia afferents to motoneurons. Both could contribute to the increased tendon jerks and exaggerated stretch reflexes.

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