Hoffmann reflex is increased after 14 days of daily repeated Achilles tendon vibration for the soleus but not for the gastrocnemii muscles

2012 ◽  
Vol 37 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Thomas Lapole ◽  
Chantal Pérot
Keyword(s):  
Achilles Tendon ◽  
Motor Units ◽  
Muscle Spindles ◽  
Triceps Surae ◽  
Control Group ◽  
Tendon Vibration ◽  
Hoffmann Reflex ◽  
Reflex Excitability ◽  
Short Period ◽  
Post Test

In a previous study, Achilles tendon vibrations were enough to improve the triceps surae (TS) activation capacities and also to slightly increase TS Hoffmann reflex (H-reflex) obtained by summing up soleus (Sol) and gastrocnemii (GM and GL) EMGs. The purpose of the present study was to analyze separately Sol and GM or GL reflexes to account for different effects of the vibrations on the reflex excitability of the slow soleus and of the gastrocnemii muscles. A control group (n = 13) and a vibration group (n = 16) were tested in pre-test and post-test conditions. The Achilles tendon vibration program consisted of 1 h of daily vibration (frequency: 50 Hz) applied during 14 days. Maximal Sol, GM and GL H-reflexes, and M-waves were recorded, and their Hmax/Mmax ratios gave the index of reflex excitability. After the vibration protocol, only Sol Hmax/Mmax was enhanced (p < 0.001). The enhanced Sol reflex excitability after vibration is in favor of a decrease in the pre-synaptic inhibition due to the repeated vibrations and the high solicitation of the reflex pathway. Those results of a short period of vibration applied at rest may be limited to the soleus because of its high density in muscle spindles and slow motor units, both structures being very sensitive to vibrations.

scholarly journals The effect of the Zahoric model in learning some kinetic sentences

2020 ◽  
Vol 19 (2) ◽  
pp. 0045
Author(s):  
M. Maison Mohammed Dr. Luma Sameer
Keyword(s):  
Teaching Method ◽  
Control Group ◽  
Second Stage ◽  
Short Period ◽  
Post Test ◽  
And Performance ◽  
And Control ◽  
Experimental Group ◽  
Positive Results ◽  
Better Than

When teaching or training fencing we find that most learners are able to perform some fencing skills during learning within the lesson, but they find it difficult to perform the same skills when linked in one sentence after a short period or in subsequent lessons, or during practical exams, so I conducted those Study to develop solutions to this problem by investing the Zahoric model and its distinctive educational steps in learning the kinetic sentences in the female blinds, and its impact on the process of learning and linking kinetic sentences in the sport of fencing and make the learning process more effective and economical.   The experimental method was used by designing the experimental and control groups with pre- and post-test on a sample of the second stage students (B22), representing the experimental group and learning the skills using the Zahoric model in its five steps, while the (D26) student representing the control group, which is learning the fencing skills according to the teaching method. Followed. The learning and performance of some kinetic sentences were evaluated by a standardized form of fencing according to the parts of the movement and their manifestations.  An educational curriculum has been prepared using the Zahorik model to learn the kinetic sentences by fencing according to the sectoral vocabulary of the second semester by following the steps of the model (activating information - acquiring - understanding - using - thinking in information). After the statistical treatments, it was concluded that the Zoharic model, designed to learn some kinetic sentences in the experimental group, gave positive results in evaluating the kinetic sentences better than the teaching method used in the control group. In light of the conclusion, it is recommended to adopt the Zoharik model in learning some kinetic sentences with a blind weapon, as it gives the learner a positive in the analysis, composition and understanding of the movements that are combined to give a kinetic sentence that ends with a touch in favor of the attacker who clearly understands where it begins and ends the syntax of the correct kinetic sentence, which resolves the sentence in his favor.

Changes in the Estimated Time Course of the Motoneuron Afterhyperpolarization Induced by Tendon Vibration

2010 ◽  
Vol 104 (6) ◽  
pp. 3240-3249 ◽  
Author(s):  
Christopher W. MacDonell ◽  
Tanya D. Ivanova ◽  
S. Jayne Garland
Keyword(s):  
Achilles Tendon ◽  
Time Constant ◽  
Time Course ◽  
Motor Units ◽  
Reciprocal Inhibition ◽  
Excitatory Input ◽  
Motor Unit Action Potential ◽  
Inhibitory Input ◽  
Tendon Vibration ◽  
Single Motor Units

Group Ia afferents are activated vigorously with high-frequency tendon vibration and provide excitatory input to the agonist muscle and inhibitory input to the antagonist muscle group via inhibitory interneurons. The purpose of this experiment was to determine whether the afterhyperpolarization (AHP) time course in humans is altered in response to tendon vibration. The AHP time course is estimated using the interval death rate (IDR) analysis, a transform of the motor unit action potential train. Single motor units from tibialis anterior (TA) were recorded as subjects held low force dorsiflexor contractions for 600 s with and without vibration. The vibratory stimulus was superimposed on the low force contraction either to the tendon of the TA or the antagonist Achilles tendon. During TA tendon vibration, the time course of the AHP, as expressed by its time constant (τ), decreased from 35.5 ms in the previbration control condition to 31.3 ms during the vibration ( P = 0.003) and returned to 36.3 ms after the vibration was removed ( P = 0.002). The AHP τ during vibration of the antagonist Achilles tendon (38.6 ms) was greater than the previbration control condition (33.6 ms; P = 0.001). It is speculated that the reduction in AHP time constant with TA vibration may have resulted alone or in combination with a modulation of motoneuron gain, an alteration of persistent inward currents and/or the restructuring of synaptic noise. A decrease in firing probability, possibly reflecting Ia reciprocal inhibition, may have been responsible for the larger AHP time constant.

scholarly journals Training-induced increase in Achilles tendon stiffness affects tendon strain pattern during running

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6764 ◽  
Author(s):  
Amelie Werkhausen ◽  
Neil J. Cronin ◽  
Kirsten Albracht ◽  
Gøran Paulsen ◽  
Askild V. Larsen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Achilles Tendon ◽  
Stance Phase ◽  
Training Group ◽  
Triceps Surae ◽  
Control Group ◽  
Tendon Stiffness ◽  
Strain Pattern ◽  
Tendon Strain ◽  
Triceps Surae Muscles

Background During the stance phase of running, the elasticity of the Achilles tendon enables the utilisation of elastic energy and allows beneficial contractile conditions for the triceps surae muscles. However, the effect of changes in tendon mechanical properties induced by chronic loading is still poorly understood. We tested the hypothesis that a training-induced increase in Achilles tendon stiffness would result in reduced tendon strain during the stance phase of running, which would reduce fascicle strains in the triceps surae muscles, particularly in the mono-articular soleus. Methods Eleven subjects were assigned to a training group performing isometric single-leg plantarflexion contractions three times per week for ten weeks, and another ten subjects formed a control group. Before and after the training period, Achilles tendon stiffness was estimated, and muscle-tendon mechanics were assessed during running at preferred speed using ultrasonography, kinematics and kinetics. Results Achilles tendon stiffness increased by 18% (P < 0.01) in the training group, but the associated reduction in strain seen during isometric contractions was not statistically significant. Tendon elongation during the stance phase of running was similar after training, but tendon recoil was reduced by 30% (P < 0.01), while estimated tendon force remained unchanged. Neither gastrocnemius medialis nor soleus fascicle shortening during stance was affected by training. Discussion These results show that a training-induced increase in Achilles tendon stiffness altered tendon behaviour during running. Despite training-induced changes in tendon mechanical properties and recoil behaviour, the data suggest that fascicle shortening patterns were preserved for the running speed that we examined. The asymmetrical changes in tendon strain patterns supports the notion that simple in-series models do not fully explain the mechanical output of the muscle-tendon unit during a complex task like running.

scholarly journals Introduction of a New Index as an Indicator for Achilles Tendon Tendinopathy

2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0044
Author(s):  
Stephan Wirth ◽  
Fabian Aregger ◽  
Anna Jungwirth-Weinberger ◽  
Thorsten Jentzsch ◽  
Andreas Hecker
Keyword(s):  
Achilles Tendon ◽  
Group Versus ◽  
Daily Practice ◽  
Initial Therapy ◽  
Triceps Surae ◽  
Future Research ◽  
Control Group ◽  
Flexor Hallucis Longus ◽  
Common Procedure ◽  
Mri Scans

Category: Sports Introduction/Purpose: Achilles tendon tendinopathy is a common problem in our daily practice. The initial therapy consists of conservative treatment and usually leads to a reduction of pain. In some cases though, there is need for surgical treatment. The most common procedure is debridement of the tendon. If there is advanced damage of the tendon, a flexor hallucis longus (FHL) transfer may be indicated. In the current literature, there is a lack of hard criteria about the indications for such a transfer. Methods: We searched our radiologic database from the years 2016 and 2017 for magnetic resonance imaging (MRI) scans of the Achilles tendon. 60 patients were included in a tendinopathy group and 60 patients in a control group with no signs of tendinopathy. Inclusion criteria were severe tendinopathy for the tendinopathy group and a normal Achilles tendon for the control group. Exclusion criteria were other relevant morphologic changes or history of relevant surgery of the lower limb. Axial MRI scans were analyzed on a level of 4-5 centimeters above the ankle joint. The area of triceps surae (TS) and FHL were measured as well as the diameter of TS and an oblique diameter of FHL (from the medial corner of the fibula to the posteromedial corner of the FHL muscle). Then, quotients of the area of the FHL/TS and diameter of the FHL/TS were built and interobserver agreement was analyzed. Results: The quotients for area and for diameter of the FHL/TS showed significantly (p<0.001) higher values in the tendinopathy group. We also found strong to very strong interobserver agreements (rho=0.744). The median value for the quotient of diameter FHL/TS was 2.0 (interquartile range [IQR] 0.8) in the tendinopathy group versus (vs) 1.7 (IQR 0.3) in the control group. The median value for the quotient of area FHL/TS was 1.8 (IQR 1.3) in the tendinopathy group vs 1.3 (IQR 0.7) in the control group. Conclusion: The quotient of the diameter FHL/TS is easy to obtain in our clinical practice. It indicates a relevant FHL hypertrophy, which occurs in advanced Achilles tendon tendinopathy. A value of 2.0 and higher is indicative of symptomatic tendinopathy and may ultimately support the indication for a FHL transfer, which should be the topic of future research.

scholarly journals Flexor hallucis longus hypertrophy secondary to Achilles tendon tendinopathy: an MRI-based case–control study

2021 ◽  
Author(s):  
Stephan H. Wirth ◽  
Octavian Andronic ◽  
Fabian Aregger ◽  
Anna Jungwirth-Weinberger ◽  
Thorsten Jentzsch ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Achilles Tendinopathy ◽  
Diameter Ratio ◽  
Triceps Surae ◽  
Control Group ◽  
Flexor Hallucis Longus ◽  
Study Group ◽  
Compensatory Mechanism ◽  
Indirect Sign ◽  
Mri Scans

Abstract Purpose The purpose of this study was to outline an indirect sign of advanced Achilles tendinopathy on magnetic resonance imaging (MRI), based on the hypothesis that these patients would present with secondary hypertrophy of the flexor hallucis longus muscle (FHL). Methods MRI scans of Achilles tendon were analyzed retrospectively in two cohorts. The study group consisted of consecutive patients presenting with clinical signs of Achilles tendinopathy and no previous surgeries, while the control group were patients that had an MRI due to other reasons and no signs of tendinopathy. Two parameters from two muscle bellies were measured and compared on axial MRI scans 4–5 cm above the ankle joint line at the level of greatest thickness: area and diameter of the triceps surae (TS) and of the FHL muscle. Ratios (FHL/TS) were calculated for area (Ar) and diameter (Dm) measurements. Interobserver agreement was analyzed. A receiver operating characteristic (ROC) curve was created for both ratios to assess potential cutoff points to differentiate between the groups. Results A total of 60 patients for each study group were included. Both ratios Ar(FHL/TS) and Dm(FHL/TS) showed significant higher values in the tendinopathy group (p < 0.001). There were strong to very strong intraclass correlation coefficients (ICC = 0.75–0.93). A diameter ratio Dm (FHL/TS) of 2.0 or higher had a sensitivity of 49% and specificity of 90% for concomitant Achilles tendinopathy. Conclusion In our patient cohort, FHL hypertrophy was observed in patients with Achilles tendinopathy as a possible compensatory mechanism. Measuring a diameter ratio Dm(FHL/TS) of 2.0 or higher on an axial MRI, may be indicative as an indirect sign of functional deterioration of the Achilles tendon.

scholarly journals TL 18161 - Evaluation of Achilles tendon oxygen saturation in patients with tendon rupture

2019 ◽  
Vol 13 (Supl 1) ◽  
pp. 95S
Author(s):  
Márcio De Faria Freitas ◽  
Mauro César Matos e Dinato ◽  
Miguel Viana Pereira Filho ◽  
Tatiana Ferreira dos Santos ◽  
Raul Dias dos Santos Filho ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Oxygen Saturation ◽  
Achilles Tendon ◽  
Near Infrared ◽  
Tendon Rupture ◽  
Achilles Tendon Rupture ◽  
Triceps Surae ◽  
Control Group ◽  
History Of ◽  
And Control

Introduction: Histopathological analyses of ruptured tendons show hypoxia-related tissue degeneration. Intrinsic factors that may cause tissue hypoxia, especially during physical exercise, may be related to Achilles tendon ruptures. Thus, the objective of the present study is to compare the resting oximetry of patients who had a ruptured Achilles tendon with that of a control group after exercise and after muscle ischemia. Methods: This was a single-center, comparative, cross-sectional observational study approved by the research ethics committee. The study assessed the Achilles tendon oxygen saturation of 2 groups: patients with a history of total Achilles tendon rupture (R: n=12) and control individuals without a history of tendon rupture (C: n=11). Oxygen saturation was measured by infrared spectroscopy on a near-infrared spectroscopy (NIRS) device (PortaMon, Artinis Medical Systems). Data were collected after the patient had rested at least 10 minutes in the supine position at the following times: test, after controlled contractions of the triceps surae muscle, and after 5 minutes of leg ischemia. The NIRS sensor was placed on the contralateral Achilles tendon in group R or on a randomized limb in group C. Data normality was confirmed using the Shapiro-Wilk test, and the groups were compared using the independent samples t test, with a significance level of p<0.05. Results: The oximetry levels of group R were similar to those of group C at rest (R: 72 ± 9% vs. C: 74 ± 6%, P=0.598), after exercise (R: 74 ± 5% vs. C: 77 ± 4%, p=0.199), and after 5 minutes of ischemia (R: 79 ± 3% vs. C: 80 ± 5, p=0.856). Conclusion: No differences in Achilles tendon oxygen saturation were identified between individuals with a history of rupture and control individuals

scholarly journals Soleus single motor units show stronger coherence with Achilles tendon vibration across a broad bandwidth relative to medial gastrocnemius units while standing

2019 ◽  
Vol 122 (5) ◽  
pp. 2119-2129 ◽  
Author(s):  
Robyn L. Mildren ◽  
Ryan M. Peters ◽  
Mark G. Carpenter ◽  
Jean-Sébastien Blouin ◽  
J. Timothy Inglis
Keyword(s):  
Achilles Tendon ◽  
Phase Locking ◽  
Motor Units ◽  
Surface Emg ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Single Motor ◽  
Single Motor Units ◽  
Cross Covariance ◽  
The Relationship

To probe the frequency characteristics of somatosensory responses in the triceps surae muscles, we previously applied suprathreshold noisy vibration to the Achilles tendon and correlated it with ongoing triceps surae muscle activity (recorded via surface EMG) during standing. Stronger responses to tendon stimuli were observed in soleus (Sol) relative to medial gastrocnemius (MGas) surface EMG; however, it is unknown whether differences in motor unit activity or limitations of surface EMG could have influenced this finding. Here, we inserted indwelling EMG into Sol and MGas to record the activity of single motor units while we applied noisy vibration (10–115 Hz) to the right Achilles tendon of standing participants. We analyzed the relationship between vibration acceleration and the spike activity of active single motor units through estimates of coherence, gain, phase, and cross-covariance. We also applied sinusoidal vibration at frequencies from 10 to 100 Hz (in 5-Hz increments) to examine whether motor units demonstrate nonlinear synchronization or phase locking at higher frequencies. Relative to MGas single motor units, Sol units demonstrated stronger coherence and higher gain with noisy vibration across a bandwidth of 7–68 Hz, and larger peak-to-peak cross-covariance at all four stimulus amplitudes examined. Sol and MGas motor unit activity was modulated over the time course of the sinusoidal stimuli across all frequencies, but their phase-locking behavior was minimal. These findings suggest Sol plays a prominent role in responding to disturbances transmitted through the Achilles tendon across a broad frequency band during standing. NEW & NOTEWORTHY We examined the relationship between Achilles tendon stimuli and spike times of single soleus (Sol) and medial gastrocnemius (MGas) motor units during standing. Relative to MGas, Sol units demonstrated stronger coherence and higher gain with noisy stimuli across a bandwidth of 7–68 Hz. Sol and MGas units demonstrated minimal nonlinear phase locking with sinusoidal stimuli. These findings indicate Sol plays a prominent role in responding to tendon stimuli across a broad frequency band.

scholarly journals Flexor Hallucis Longus Hypertrophy Secondary to Achilles Tendon Tendinopathy: An MRI-based Case-Control Study

2020 ◽  
Author(s):  
Stephan Wirth ◽  
Octavian Andronic ◽  
Fabian Aregger ◽  
Anna Jungwirth-Weinberger ◽  
Thorsten Jentzsch ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Achilles Tendinopathy ◽  
Diameter Ratio ◽  
Triceps Surae ◽  
Control Group ◽  
Flexor Hallucis Longus ◽  
Study Group ◽  
Compensatory Mechanism ◽  
Indirect Sign ◽  
Mri Scans

Abstract Background: The purpose of this study was to outline an indirect sign of advanced Achilles tendinopathy on magnetic resonance imaging (MRI), based on the hypothesis that these patients would present with secondary hypertrophy of the flexor hallucis longus muscle (FHL).Methods: MRI scans of Achilles tendon were analyzed retrospectively in two cohorts. The study group consisted of consecutive patients presenting with clinical signs of Achilles tendinopathy and no previous surgeries, whilst the control group were patients that had an MRI due to other reasons and no signs of tendinopathy. Two parameters from two muscle bellies were measured and compared on axial MRI scans 4 to 5 cm above the ankle joint line at the level of greatest thickness: area and diameter of the triceps surae (TS) and of the FHL muscle. Ratios (FHL/TS) were calculated for area (Ar) and diameter (Dm) measurements. Interobserver agreement was analyzed. A receiver operating characteristic (ROC) curve was created for both ratios to assess potential cut-off points to differentiate between the groups.Results: A total of 60 patients for each study group were included. Both ratios, Ar(FHL/TS) and Dm(FHL/TS) showed significant higher values in the tendinopathy group (p<0.001). There were strong to very strong intraclass correlation coefficients (ICC=0.75-0.93). A diameter ratio Dm (FHL/TS) of 2.0 or higher had a sensitivity of 49% and specificity of 90% for concomitant Achilles tendinopathy.Conclusion: In our patient cohort, FHL hypertrophy was observed in patients with Achilles tendinopathy as a possible compensatory mechanism. Measuring a diameter ratio Dm(FHL/TS) of 2.0 or higher on an axial MRI, may be indicative as an indirect sign of functional deterioration of the Achilles tendon.

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