scholarly journals Soleus H-Reflex Inhibition Decreases During 30 s Static Stretching of Plantar Flexors, Showing Two Recovery Steps

2018 ◽  
Vol 9 ◽  
Author(s):  
Francesco Budini ◽  
Monica Christova ◽  
Eugen Gallasch ◽  
Dietmar Rafolt ◽  
Markus Tilp
2016 ◽  
Vol 27 (5) ◽  
pp. 511-522 ◽  
Author(s):  
Francesco Budini ◽  
Markus Tilp

AbstractSpinal reflex excitability is traditionally assessed to investigate neural adjustments that occur during human movement. Different experimental procedures are known to condition spinal reflex excitability. Among these, lengthening movements and static stretching the human triceps have been investigated over the last 50 years. The purpose of this review is to shed light on several apparent incongruities in terms of magnitude and duration of the reported results. In the present review dissimilarities in neuro-spinal changes are examined in relation to the methodologies applied to condition and measure them. Literature that investigated three different conditioning procedures was reviewed: passive dorsiflexion, active dorsiflexion through antagonists shortening and eccentric plantar-flexors contractions. Measurements were obtained before, during and after lengthening or stretching. Stimulation intensities and time delays between conditioning procedures and stimuli varied considerably. H-reflex decreases immediately as static stretching is applied and in proportion to the stretch degree. During dorsiflexions the inhibition is stronger with greater dorsiflexion angular velocity and at lower nerve stimulation intensities, while it is weaker if any concomitant muscle contraction is performed. Within 2 s after a single passive dorsiflexion movement, H-reflex is strongly inhibited, and this effect disappears within 15 s. Dorsiflexions repeated over 1 h and prolonged static stretching training induce long-lasting inhibition. This review highlights that the apparent disagreement between studies is ascribable to small methodological differences. Lengthening movements and stretching can strongly influence spinal neural pathways. Results interpretation, however, needs careful consideration of the methodology applied.


2014 ◽  
Vol 20 (1) ◽  
pp. 65-70
Author(s):  
Leonardo A. Pasqua ◽  
Nilo M. Okuno ◽  
Mayara V. Damasceno ◽  
Adriano. E. Lima-Silva ◽  
Rômulo Bertuzzi

This study analyzed the effect of static stretching on performance during drop jumps. Furthermore, we investigated if a reduction in drop height would compensate the stretching-caused alterations. Ten physically active male subjects performed drop jumps at four different drop heights without static stretching for the optimal drop height determination. After, they performed drop jumps on two drop heights with static stretching previously. The jump height, contact time and reactive strength index were significantly affected by static stretching. However, only the contact time was significantly improved by the reduction in drop height with previous static stretching. Our results suggest that the decrement in performance after static stretching could be partially compensated by a reduction in drop height, which decreases the contact time near a non-stretching jump condition. This can be explained by the lower landing velocity and, possibly, the smaller reduction in the activation of the plantar flexors muscles. In conclusion, the reduction in drop height seems to be interesting after a static stretching session, aiming to expose the athletes to lower impact forces to maintain jump performance.


2019 ◽  
Vol 127 (1) ◽  
pp. 89-97 ◽  
Author(s):  
Carla Silva-Batista ◽  
Jumes Leopoldino de Oliveira Lira ◽  
Fabian J. David ◽  
Daniel M. Corcos ◽  
Eugenia Casella Tavares Mattos ◽  
...  

This study had two objectives: 1) to compare the effects of 3 wk of resistance training (RT) and resistance training with instability (RTI) on evoked reflex responses at rest and during maximal voluntary isometric contraction (MVIC) of individuals with Parkinson’s disease (PD) and 2) to determine the effectiveness of RT and RTI in moving values of evoked reflex responses of individuals with PD toward values of age-matched healthy control subjects (HCs) ( z-score analysis). Ten individuals in the RT group and 10 in the RTI group performed resistance exercises twice a week for 3 wk, but only the RTI group included unstable devices. The HC group ( n = 10) were assessed at pretest only. Evoked reflex responses at rest (H reflex and M wave) and during MVIC [supramaximal M-wave amplitude (Msup) and supramaximal V-wave amplitude (Vsup)] of the plantar flexors were assessed before and after the experimental protocol. From pretraining to posttraining, only RTI increased ratio of maximal H-reflex amplitude to maximal M-wave amplitude at rest (Hmax/Mmax), Msup, Vsup/Msup, and peak torque of the plantar flexors ( P < 0.05). At posttraining, RTI was more effective than RT in increasing resting Hmax and Vsup and in moving these values to those observed in HCs ( P < 0.05). We conclude that short-term RTI is more effective than short-term RT in modulating H-reflex excitability and in increasing efferent neural drive, approaching average values of HCs. Thus short-term RTI may cause positive changes at the spinal and supraspinal levels in individuals with PD. NEW & NOTEWORTHY Maximal H-reflex amplitude (Hmax) at rest and efferent neural drive [i.e., supramaximal V-wave amplitude (Vsup)] to skeletal muscles during maximal contraction are impaired in individuals with Parkinson’s disease. Short-term resistance training with instability was more effective than short-term resistance training alone in increasing Hmax and Vsup of individuals with Parkinson’s disease, reaching the average values of healthy control subjects.


1996 ◽  
Vol 5 (2) ◽  
pp. 172-182 ◽  
Author(s):  
Andrew L. McDonough ◽  
Joseph P. Weir

The purpose of this case study was to investigate reflex inhibition of the quadriceps femoris in a subject with postsurgical edema of the left knee. The subject was a 45-year-old male with a traumatic knee injury with resultant edema who underwent elective arthroscopic surgery. Reflex inhibition was assessed by H-reflex elicitation in the femoral nerve and surface electromyography of the quadriceps. To assess the degree of edema, direct circumferential measurements were taken. On the first presurgical visit, the left knee demonstrated mild edema with a decrease in H-reflex amplitudes. Two days after surgery, a further reduction in amplitudes and more swelling were demonstrated followed by an increase in amplitudes and a reduction in edema on the 28th postoperative day. These findings document a relationship between reflex inhibition and joint swelling that was previously described in experimental models where joint edema was simulated.


2012 ◽  
Vol 112 (1) ◽  
pp. 54-63 ◽  
Author(s):  
Carolina Vila-Chã ◽  
Deborah Falla ◽  
Miguel Velhote Correia ◽  
Dario Farina

This study examined the effects of 3 wk of either endurance or strength training on plasticity of the neural mechanisms involved in the soleus H reflex and V wave. Twenty-five sedentary healthy subjects were randomized into an endurance group ( n = 13) or strength group ( n = 12). Evoked V-wave, H-reflex, and M-wave recruitment curves, maximal voluntary contraction (MVC), and time-to-task-failure (isometric contraction at 40% MVC) of the plantar flexors were recorded before and after training. Following strength training, MVC of the plantar flexors increased by 14.4 ± 5.2% in the strength group ( P < 0.001), whereas time-to-task-failure was prolonged in the endurance group (22.7 ± 17.1%; P < 0.05). The V wave-to-maximal M wave (V/Mmax) ratio increased significantly (55.1 ± 28.3%; P < 0.001) following strength training, but the maximal H wave-to-maximal M wave (Hmax/Mmax) ratio remained unchanged. Conversely, in the endurance group the V/Mmax ratio was not altered, whereas the Hmax/Mmax ratio increased by 30.8 ± 21.7% ( P < 0.05). The endurance training group also displayed a reduction in the H-reflex excitability threshold while the H-reflex amplitude on the ascending limb of the recruitment curve increased. Strength training only elicited a significant decrease in H-reflex excitability threshold, while H-reflex amplitudes over the ascending limb remained unchanged. These observations indicate that the H-reflex pathway is strongly involved in the enhanced endurance resistance that occurs following endurance training. On the contrary, the improvements in MVC following strength training are likely attributed to increased descending drive and/or modulation in afferents other than Ia afferents.


2017 ◽  
Vol 102 (8) ◽  
pp. 901-910 ◽  
Author(s):  
Francesco Budini ◽  
Eugen Gallasch ◽  
Monica Christova ◽  
Dietmar Rafolt ◽  
Andreas Benedikt Rauscher ◽  
...  

2018 ◽  
Vol 124 (4) ◽  
pp. 950-959 ◽  
Author(s):  
James D. Young ◽  
Alyssa-Joy Spence ◽  
David G. Behm

Roller massage (RM) interventions have shown acute increases in range of motion (ROM) and pain pressure threshold (PPT). It is unclear whether the RM-induced increases can be attributed to changes in neural or muscle responses. The purpose of this study was to evaluate the effect of altered afferent input via application of RM on spinal excitability, as measured with the Hoffmann (H-) reflex. A randomized within-subjects design was used. Three 30-s bouts of RM were implemented on a rested, nonexercised, injury-free muscle with 30 s of rest between bouts. The researcher applied RM to the plantar flexors at three intensities of pain: high, moderate, and sham. Measures included normalized M-wave and H-reflex peak-to-peak amplitudes before, during, and up to 3 min postintervention. M-wave and H-reflex measures were highly reliable. RM resulted in significant decreases in soleus H-reflex amplitudes. High-intensity, moderate-intensity, and sham conditions decreased soleus H-reflex amplitudes by 58%, 43%, and 19%, respectively. H-reflexes induced with high-intensity rolling discomfort or pain were significantly lower than moderate and sham conditions. The effects were transient in nature, with an immediate return to baseline following RM. This is the first evidence of RM-induced modulation of spinal excitability. The intensity-dependent response observed indicates that rolling pressure or pain perception may play a role in modulation of the inhibition. Roller massage-induced neural modulation of spinal excitability may explain previously reported increases in ROM and PPT. NEW & NOTEWORTHY Recent evidence indicates that the benefits of foam rolling and roller massage are primarily accrued through neural mechanisms. The present study attempts to determine the neuromuscular response to roller massage interventions. We provide strong evidence of roller massage-induced neural modulation of spinal excitability to the soleus. It is plausible that reflex inhibition may explain subsequent increases in pain pressure threshold.


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