Nonlinear twitch torque summation by motor units activated at M-wave and H-reflex latencies

2009 ◽  
Vol 40 (2) ◽  
pp. 221-230 ◽  
Author(s):  
Jesse C. Dean ◽  
David F. Collins
Keyword(s):  
Motor Units ◽  
H Reflex ◽  
M Wave

scholarly journals Effect of ageing on the electrical and mechanical properties of human soleus motor units activated by the H reflex and M wave

2003 ◽  
Vol 548 (2) ◽  
pp. 649-661 ◽  
Author(s):  
G Scaglioni ◽  
M V Narici ◽  
N A Maffiuletti ◽  
M Pensini ◽  
A Martin
Keyword(s):  
Mechanical Properties ◽  
Motor Units ◽  
H Reflex ◽  
M Wave

Electrical and mechanical Hmax-to-Mmaxratio in power- and endurance-trained athletes

2001 ◽  
Vol 90 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Nicola A. Maffiuletti ◽  
Alain Martin ◽  
Nicolas Babault ◽  
Manuela Pensini ◽  
Brigitte Lucas ◽  
...  
Keyword(s):  
Wave Amplitude ◽  
Motor Units ◽  
Afferent Input ◽  
H Reflex ◽  
The Other ◽  
Power Training ◽  
Force Output ◽  
M Wave ◽  
Reflex Excitability ◽  
Slow Twitch

The aim of this study was to compare the mechanical and electromyographic (EMG) characteristics of soleus motor units activated during maximal H reflex and direct M response among subjects with different histories of physical activity. Power-trained athletes produced stronger twitches, with a higher rate of twitch tension buildup and relaxation, than their endurance counterparts for both maximal H-reflex and maximal M-wave responses. The maximal H-reflex-to-maximal M-wave ratios for both force output (twitch) and EMG wave amplitude were significantly lower in power-trained than endurance-trained athletes. However, power-trained athletes exhibited a significantly greater twitch-to-EMG ratio for the reflexly activated motor units with respect to the entire motor pool, whereas endurance-trained athletes had comparable twitch-to-EMG ratios for both reflexly and directly activated units. Power training increases the force output of the whole ensemble of the motor units, thereby compensating for the lower efficacy of the reflex transmission between Ia spindle afferent input and soleus α-motoneuron. On the other hand, the lower level of force evoked by the reflexly activated units in endurance-trained athletes is associated with a greater motor pool reflex excitability. Therefore, endurance-trained athletes produce the necessary force by recruitment of more slow-twitch units than do other subjects for comparable levels of force and type of task.

scholarly journals Acute Effects of Kinesiology Taping Stretch Tensions on Soleus and Gastrocnemius H-Reflex Modulations

2021 ◽  
Vol 18 (9) ◽  
pp. 4411
Author(s):  
Yung-Sheng Chen ◽  
Shi Zhou ◽  
Zachary J. Crowley-McHattan ◽  
Pedro Bezerra ◽  
Wei-Chin Tseng ◽  
...  
Keyword(s):  
H Reflex ◽  
Triceps Surae ◽  
Reflex Modulation ◽  
Hoffmann Reflex ◽  
Acute Effects ◽  
Physically Active ◽  
M Wave ◽  
Subject Design ◽  
Minor Influence ◽  
Order Paper

This study examined the acute effects of stretch tensions of kinesiology taping (KT) on the soleus (SOL), medial (MG), and lateral (LG) gastrocnemius Hoffmann-reflex (H-reflex) modulation in physically active healthy adults. A cross-over within-subject design was used in this study. Twelve physically active collegiate students voluntarily participated in the study (age = 21.3 ± 1.2 years; height = 175.6 ± 7.1 cm; body weight = 69.9 ± 7.1 kg). A standard Y-shape of KT technique was applied to the calf muscles. The KT was controlled in three tension intensities in a randomised order: paper-off, 50%, and 100% of maximal stretch tension of the tape. The peak-to-peak amplitude of maximal M-wave (Mmax) and H-reflex (Hmax) responses in the SOL, MG, and LG muscles were assessed before taping (pre-taping), taping, and after taping (post-taping) phases in the lying prone position. The results demonstrated significantly larger LG Hmax responses in the pre-taping condition than those in the post-taping condition during paper-off KT (p = 0.002). Moreover, the ΔHmax/Mmax of pre- and post-taping in the SOL muscle was significantly larger during 50%KT tension than that of paper-off (p = 0.046). In conclusion, the stretch tension of KT contributes minor influence on the spinal motoneuron excitability in the triceps surae during rest.

Differences in soleus H-reflex to M-wave ratio between obese and non-obese individuals

2021 ◽  
Vol 84 ◽  
pp. 105322
Author(s):  
Nicola A. Maffiuletti ◽  
Rosa Visscher ◽  
Alessandra De Col ◽  
Alessandro Sartorio
Keyword(s):  
H Reflex ◽  
M Wave

Interlimb coupling from the arms to legs is differentially specified for populations of motor units comprising the compound H-reflex during “reduced” human locomotion

2010 ◽  
Vol 208 (2) ◽  
pp. 157-168 ◽  
Author(s):  
Rinaldo A. Mezzarane ◽  
Marc Klimstra ◽  
Allen Lewis ◽  
Sandra R. Hundza ◽  
E. Paul Zehr
Keyword(s):  
Motor Units ◽  
Human Locomotion ◽  
H Reflex ◽  
Interlimb Coupling

Between-day reliability of the trapezius muscle H-reflex and M-wave

2015 ◽  
Vol 52 (6) ◽  
pp. 1066-1071 ◽  
Author(s):  
Steffen Vangsgaard ◽  
Ernst a. Hansen ◽  
Pascal Madeleine
Keyword(s):  
Trapezius Muscle ◽  
H Reflex ◽  
M Wave

Arthrogenic Muscle Inhibition in the Leg Muscles of Subjects Exhibiting Functional Ankle Instability

2005 ◽  
Vol 26 (12) ◽  
pp. 1055-1061 ◽  
Author(s):  
Eric D. McVey ◽  
Riann M. Palmieri ◽  
Carrie L. Docherty ◽  
Steven M. Zinder ◽  
Christopher D. Ingersoll
Keyword(s):  
Tibialis Anterior ◽  
Ankle Instability ◽  
H Reflex ◽  
Functional Ankle Instability ◽  
Injured Limb ◽  
Lateral Ankle ◽  
M Wave ◽  
Muscle Inhibition ◽  
Lateral Ankle Ligaments ◽  
Arthrogenic Muscle Inhibition

Background: Functional ankle instability or a subjective report of “giving way” at the ankle may be present in up to 40% of patients after a lateral ankle sprain. Damage to mechanoreceptors within the lateral ankle ligaments after injury is hypothesized to interrupt neurologic feedback mechanisms resulting in functional ankle instability. The altered input can lead to weakness of muscles surrounding a joint, or arthrogenic muscle inhibition. Arthrogenic muscle inhibition may be the underlying cause of functional ankle instability. Establishing the involvement of arthrogenic muscle inhibition in functional ankle instability is critical to understanding the underlying mechanisms or chronic ankle instability. The purpose of this investigation was to determine if arthrogenic muscle inhibition is present in the ankle joint musculature of patients exhibiting unilateral functional ankle instability. Methods: Twenty-nine subjects, 15 with unilateral functional ankle instability and 14 healthy control subjects, consented to participate. Bilateral soleus, peroneal, and tibialis anterior H-reflex and M-wave recruitment curves were obtained. Maximal H-reflex and maximal M-wave values were identified and the H:M ratios were calculated for data analysis. Separate 1 × 2 ANOVA were done for both the functional ankle instability and control groups to evaluate differences between limbs on the H:M ratios. Bonferroni multiple comparison procedures were used for post hoc comparisons ( p ≤ 0.05). Results: The soleus and peroneal H:M ratios for subjects with functional ankle instability were smaller in the injured limb when compared with the uninjured limb (p < 0.05). No limb difference was detected for the tibialis anterior H:M ratio in the functional ankle instability group ( p = 0.904). No side-to-side differences were detected for the H:M ratios in patients reporting no history of ankle injury ( p > 0.05). Conclusions: Depressed H:M ratios in the injured limb suggest that arthrogenic muscle inhibition is present in the ankle musculature of patients exhibiting functional ankle instability. Establishing and using therapeutic techniques to reverse arthrogenic muscle inhibition may reduce the incidence of functional ankle instability.

Impulse propagation and muscle activation in long maximal voluntary contractions

1989 ◽  
Vol 67 (5) ◽  
pp. 1835-1842 ◽  
Author(s):  
C. K. Thomas ◽  
J. J. Woods ◽  
B. Bigland-Ritchie
Keyword(s):  
Tibialis Anterior ◽  
Muscle Activation ◽  
Motor Units ◽  
Voluntary Contraction ◽  
Mass Action ◽  
M Wave ◽  
Force Reduction ◽  
Small Decline ◽  
Voluntary Contractions ◽  
Do So

With fatigue, force generation may be limited by several factors, including impaired impulse transmission and/or reduced motor drive. In 5-min isometric maximal voluntary contraction, no decline was seen in the peak amplitude of the tibialis anterior compound muscle mass action potential (M wave) either during or immediately after the voluntary effort, provided maximal nerve stimulation was retained. For first dorsal interosseous (FDI) muscle, M wave amplitudes declined by 19.4 +/- 1.6% during the first 2 min but did not change significantly thereafter, despite the continued force reduction (up to 94% in 5 min for both muscles). The duration of the FDI M waves increased (greater than 30%), suggesting that the small decline in amplitude was the result of increased dispersion between the responses of different motor units. Some subjects kept FDI maximally activated throughout, but when they used tibialis anterior, twitch occlusion and tetanic muscle stimulation showed that most subjects were usually only able to do so for the first 60 s and thereafter only during brief “extra efforts.” Thus force loss during isometric voluntary contractions sustained at the highest intensities results mainly from failure of processes within the muscle fibers.

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