scholarly journals Multi- and Single-Joint Resistance Exercises Promote Similar Plantar Flexor Activation in Resistance Trained Men

2020 ◽  
Vol 17 (24) ◽  
pp. 9487
Author(s):  
Paulo Gentil ◽  
Daniel Souza ◽  
Murillo Santana ◽  
Rafael Ribeiro Alves ◽  
Mário Hebling Campos ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Negative Impact ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Plantar Flexors ◽  
Lateral Gastrocnemius ◽  
Leg Press ◽  
Electromyographic Signal ◽  
Triceps Surae Muscles ◽  
Gastrocnemius Muscles

The present study aimed to compare soleus, lateral, and medial gastrocnemius muscles activation during leg press and calf raise exercises in trained men. The study involved 22 trained men (27.1 ± 3.6 years, 82.7 ± 6.6 kg, 177.5 ± 5.2 cm, 3.6 ± 1.4 experience years) who performed one set of each exercise using a 10-repetition maximum (10RM) load in a counterbalanced randomized order and separated by 10 min of rest. The electromyographic signal was measured for the three major plantar flexors: soleus, medial, and lateral gastrocnemius. A comparison between exercises showed that the mean adjusted by peak values during the leg press were 49.20% for the gastrocnemius lateralis, 51.31% for the gastrocnemius medialis, and 50.76% for the soleus. Values for calf raise were 50.70%, 52.19%, and 51.34% for the lateral, medial gastrocnemius, and soleus, respectively. There were no significant differences between exercises for any muscle (lateral gastrocnemius (p = 0.230), medial gastrocnemius (p = 0.668), and soleus (p = 0.535)). The present findings suggest that both leg press and calf raises can be used with the purpose to recruit triceps surae muscles. This bring the suggestion that one can chose between exercises based on personal preferences and practical aspects, without any negative impact on muscle activation.

scholarly journals Evidence of adaptations of locomotor neural drive in response to enhanced intermuscular connectivity between the triceps surae muscles of the rat

2017 ◽  
Vol 118 (3) ◽  
pp. 1677-1689 ◽  
Author(s):  
Michel Bernabei ◽  
Jaap H. van Dieën ◽  
Huub Maas
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Muscle Activation ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Connective Tissues ◽  
Muscle Belly ◽  
The Central Nervous System ◽  
Triceps Surae Muscles ◽  
Gastrocnemius Muscles

The aims of this study were to investigate changes 1) in the coordination of activation of the triceps surae muscle group, and 2) in muscle belly length of soleus (SO) and lateral gastrocnemius (LG) during locomotion (trotting) in response to increased stiffness of intermuscular connective tissues in the rat. We measured muscle activation and muscle belly lengths, as well as hindlimb kinematics, before and after an artificial enhancement of the connectivity between SO and LG muscles obtained by implanting a tissue-integrating surgical mesh at the muscles’ interface. We found that SO muscle activation decreased to 62%, while activation of LG and medial gastrocnemius muscles increased to 134 and 125%, respectively, compared with the levels measured preintervention. Although secondary additional or amplified activation bursts were observed with enhanced connectivity, the primary pattern of activation over the stride and the burst duration were not affected by the intervention. Similar muscle length changes after manipulation were observed, suggesting that length feedback from spindle receptors within SO and LG was not affected by the connectivity enhancement. We conclude that peripheral mechanical constraints given by morphological (re)organization of connective tissues linking synergists are taken into account by the central nervous system. The observed shift in activity toward the gastrocnemius muscles after the intervention suggests that these larger muscles are preferentially recruited when the soleus has a similar mechanical disadvantage in that it produces an unwanted flexion moment around the knee. NEW & NOTEWORTHY Connective tissue linkages between muscle-tendon units may act as an additional mechanical constraint on the musculoskeletal system, thereby reducing the spectrum of solutions for performing a motor task. We found that intermuscular coordination changes following intermuscular connectivity enhancement. Besides showing that the extent of such connectivity is taken into account by the central nervous system, our results suggest that recruitment of triceps surae muscles is governed by the moments produced at the ankle-knee joints.

Influences of premotoneuronal command statistics on the scaling of motor output variability during isometric plantar flexion

2013 ◽  
Vol 110 (11) ◽  
pp. 2592-2606 ◽  
Author(s):  
Renato N. Watanabe ◽  
Fernando H. Magalhães ◽  
Leonardo A. Elias ◽  
Vitor M. Chaud ◽  
Emanuele M. Mello ◽  
...  
Keyword(s):  
Point Processes ◽  
Plantar Flexion ◽  
Spike Trains ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Lateral Gastrocnemius ◽  
Output Variability ◽  
Motor Output Variability ◽  
Wide Range ◽  
Gastrocnemius Muscles

This study focuses on neuromuscular mechanisms behind ankle torque and EMG variability during a maintained isometric plantar flexion contraction. Experimentally obtained torque standard deviation (SD) and soleus, medial gastrocnemius, and lateral gastrocnemius EMG envelope mean and SD increased with mean torque for a wide range of torque levels. Computer simulations were performed on a biophysically-based neuromuscular model of the triceps surae consisting of premotoneuronal spike trains (the global input, GI) driving the motoneuron pools of the soleus, medial gastrocnemius, and lateral gastrocnemius muscles, which activate their respective muscle units. Two types of point processes were adopted to represent the statistics of the GI: Poisson and Gamma. Simulations showed a better agreement with experimental results when the GI was modeled by Gamma point processes having lower orders (higher variability) for higher target torques. At the same time, the simulations reproduced well the experimental data of EMG envelope mean and SD as a function of mean plantar flexion torque, for the three muscles. These results suggest that the experimentally found relations between torque-EMG variability as a function of mean plantar flexion torque level depend not only on the intrinsic properties of the motoneuron pools and the muscle units innervated, but also on the increasing variability of the premotoneuronal GI spike trains when their mean rates increase to command a higher plantar flexion torque level. The simulations also provided information on spike train statistics of several hundred motoneurons that compose the triceps surae, providing a wide picture of the associated mechanisms behind torque and EMG variability.

Muscle activation and its distribution within human triceps surae muscles

2005 ◽  
Vol 99 (3) ◽  
pp. 1149-1156 ◽  
Author(s):  
Ryuta Kinugasa ◽  
Yasuo Kawakami ◽  
Tetsuo Fukunaga
Keyword(s):  
Muscle Activation ◽  
Spin Echo ◽  
Region Of Interest ◽  
Transverse Relaxation Time ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Active Muscle ◽  
Percentage Area ◽  
The Mean ◽  
Triceps Surae Muscles

The purposes of this study were 1) to quantify the volume of activated parts within a whole muscle and 2) to examine activated area distributions along the length of muscle. Seven male subjects performed five sets of 10 repetitions of a single-leg calf-raise exercise with the knee fully extended. Transverse relaxation time (T2)-weighted spin echo images were acquired before and immediately after the exercise. A range of pixels with a T2 greater than the mean +1 SD of the region of interest (ROI) from the preexercise image and pixels with a T2 lower than the mean + SD of the ROI from the postexercise image were defined as “active” muscle. The active muscle images were three dimensionally reconstructed, from which the volume of the activated muscle was determined for individual triceps surae (TS) muscles. Our data indicate that ∼46% of the medial gastrocnemius (MG) muscle was activated during the exercise, with activation of the lateral gastrocnemius (LG) and soleus (Sol) muscles being ∼35%. In the MG, distal portions had a greater percentage area of activated muscle than the proximal portions ( P < 0.05), which was consistent with the results regarding electromyogram activity. In contrast, regional activation differences were not observed in the LG and Sol. These findings suggest that the amounts of activated muscle and its distribution would be different among TS muscles.

Neural Compensation Within the Human Triceps Surae During Prolonged Walking

2011 ◽  
Vol 105 (2) ◽  
pp. 548-553 ◽  
Author(s):  
Neil J. Cronin ◽  
Jussi Peltonen ◽  
Thomas Sinkjaer ◽  
Janne Avela
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Neural Activation ◽  
Fascicle Length ◽  
Muscle Fascicle ◽  
Compound Action Potentials ◽  
Triceps Surae Muscles ◽  
Short Time

During human walking, muscle activation strategies are approximately constant across consecutive steps over a short time, but it is unknown whether they are maintained over a longer duration. Prolonged walking may increase tendinous tissue (TT) compliance, which can influence neural activation, but the neural responses of individual muscles have not been investigated. This study investigated the hypothesis that muscle activity is up- or down-regulated in individual triceps surae muscles during prolonged walking. Thirteen healthy subjects walked on a treadmill for 60 min at 4.5 km/h, while triceps surae muscle activity, maximal muscle compound action potentials, and kinematics were recorded every 5 min, and fascicle lengths were estimated at the beginning and end of the protocol using ultrasound. After 1 h of walking, soleus activity increased by 9.3 ± 0.2% ( P < 0.05) and medial gastrocnemius activity decreased by 9.3 ± 0.3% ( P < 0.01). Gastrocnemius fascicle length at ground contact shortened by 4.45 ± 0.99% ( P < 0.001), whereas soleus fascicle length was unchanged ( P = 0.988). Throughout the stance phase, medial gastrocnemius fascicle lengthening decreased by 44 ± 13% ( P < 0.001), whereas soleus fascicle lengthening amplitude was unchanged ( P = 0.650). The data suggest that a compensatory neural strategy exists between triceps surae muscles and that changes in muscle activation are generally mirrored by changes in muscle fascicle length. These findings also support the notion of muscle-specific changes in TT compliance after prolonged walking and highlight the ability of the CNS to maintain relatively constant movement patterns in spite of neuromechanical changes in individual muscles.

Effects of 12-wk eccentric calf muscle training on muscle-tendon glucose uptake and SEMG in patients with chronic Achilles tendon pain

2014 ◽  
Vol 117 (2) ◽  
pp. 105-111 ◽  
Author(s):  
Tahir Masood ◽  
Kari Kalliokoski ◽  
S. Peter Magnusson ◽  
Jens Bojsen-Møller ◽  
Taija Finni
Keyword(s):  
Achilles Tendon ◽  
Glucose Uptake ◽  
Plantar Flexion ◽  
Achilles Tendinopathy ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Flexor Hallucis Longus ◽  
Myoelectric Activity ◽  
Plantar Flexors ◽  
Lateral Gastrocnemius

High-load eccentric exercises have been a key component in the conservative management of chronic Achilles tendinopathy. This study investigated the effects of a 12-wk progressive, home-based eccentric rehabilitation program on ankle plantar flexors' glucose uptake (GU) and myoelectric activity and Achilles tendon GU. A longitudinal study design with control ( n = 10) and patient ( n = 10) groups was used. Surface electromyography (SEMG) from four ankle plantar flexors and GU from the same muscles and the Achilles tendon were measured during submaximal intermittent isometric plantar flexion task. The results indicated that the symptomatic leg was weaker ( P < 0.05) than the asymptomatic leg at baseline, but improved ( P < 0.001) with eccentric rehabilitation. Additionally, the rehabilitation resulted in greater GU in both soleus ( P < 0.01) and lateral gastrocnemius ( P < 0.001) in the symptomatic leg, while the asymptomatic leg displayed higher uptake for medial gastrocnemius and flexor hallucis longus ( P < 0.05). While both patient legs had higher tendon GU than the controls ( P < 0.05), there was no rehabilitation effect on the tendon GU. Concerning SEMG, at baseline, soleus showed more relative activity in the symptomatic leg compared with both the asymptomatic and control legs ( P < 0.05), probably reflecting an effort to compensate for the decreased force potential. The rehabilitation resulted in greater SEMG activity in the lateral gastrocnemius ( P < 0.01) of the symptomatic leg with no other within- or between-group differences. Eccentric rehabilitation was effective in decreasing subjective severity of Achilles tendinopathy. It also resulted in redistribution of relative electrical activity, but not metabolic activity, within the triceps surae muscle.

scholarly journals Architecture of the Triceps Surae Muscles Complex in Patients with Spastic Hemiplegia: Implication for the Limited Utility of the Silfverskiöld Test

2019 ◽  
Vol 8 (12) ◽  
pp. 2096 ◽  
Author(s):  
Kun-Bo Park ◽  
Sun Young Joo ◽  
Hoon Park ◽  
Isaac Rhee ◽  
Jong-Kwan Shin ◽  
...  
Keyword(s):  
Mixed Model ◽  
Operative Procedure ◽  
Pennation Angle ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Fascicle Length ◽  
Lateral Gastrocnemius ◽  
Group I ◽  
Equinus Deformity ◽  
Triceps Surae Muscles

The Silfverskiöld test has long been used as an important tool for determining the affected muscles of the triceps surae in patients with equinus deformity. However, the test may not reflect the altered interactions between the muscles of the triceps which are affected by spasticity. The purpose of this study was to compare the architectural properties of the triceps surae muscles complex using ultrasonography, between hemiplegic patients and typically-developing children. Specifically, we wished to examine any differences in the architecture of the three muscles with various angle configurations of the knee and ankle joints. Ultrasound images of the medial gastrocnemius, lateral gastrocnemius, and soleus were acquired from paretic (group I) and non-paretic (group II) legs of ten patients and the legs (group III) of 10 age-matched normal children. A mixed model was used to evaluate the differences in the measurements of muscle architecture among the groups and the effects of various joint configurations on the measurements within the muscles. Compared to the results of measurements in groups II and III, the fascicle length was not different in the medial gastrocnemius of a paretic leg but it was longer in the lateral gastrocnemius and shorter in the soleus; the pennation angle was smaller in both medial and lateral gastrocnemii and was not different in the soleus; and the muscle thickness was found to be reduced in the three muscles of the paretic leg. Contrary to the observations in both the medial and lateral gastrocnemii, the fascicle length was increased and the pennation angle was decreased in the soleus with an increase of knee flexion. Through the current simulation study of the Silfverskiöld test using ultrasonography, we found that the changes detected in the architectural properties of the three muscles induced by systematic variations of the position at the ankle and the knee joints were variable. We believe that the limited utility of the Silfverskiöld test should be considered in determining an appropriate operative procedure to correct the equinus deformity in patients with altered architecture of the muscles in conditions such as cerebral palsy, as the differing muscle architectures of the triceps surae complex may affect the behavior of the muscles during the Silfverskiöld test.

scholarly journals Absence of lateral gastrocnemius activity and differential motor unit behavior in soleus and medial gastrocnemius during standing balance

2014 ◽  
Vol 116 (2) ◽  
pp. 140-148 ◽  
Author(s):  
Martin E. Héroux ◽  
Christopher J. Dakin ◽  
Billy L. Luu ◽  
John Timothy Inglis ◽  
Jean-Sébastien Blouin
Keyword(s):  
Firing Rate ◽  
Motor Unit ◽  
Standing Position ◽  
Standing Balance ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Isometric Contractions ◽  
Functional Requirements ◽  
Vertical Projection ◽  
Lateral Gastrocnemius

In a standing position, the vertical projection of the center of mass passes in front of the ankle, which requires active plantar-flexor torque from the triceps surae to maintain balance. We recorded motor unit (MU) activity in the medial (MG) and lateral (LG) gastrocnemius muscle and the soleus (SOL) in standing balance and voluntary isometric contractions to understand the effect of functional requirements and descending drive from different neural sources on motoneuron behavior. Single MU activity was recorded in seven subjects with wire electrodes in the triceps surae. Two 3-min standing balance trials and several ramp-and-hold contractions were performed. Lateral gastrocnemius MU activity was rarely observed in standing. The lowest thresholds for LG MUs in ramp contractions were 20–35 times higher than SOL and MG MUs ( P < 0.001). Compared with MUs from the SOL, MG MUs were intermittently active ( P < 0.001), had higher recruitment thresholds ( P = 0.022), and greater firing rate variability ( P < 0.001); this difference in firing rate variability was present in standing balance and isometric contractions. In SOL and MG MUs, both recruitment of new MUs ( R2 = 0.59–0.79, P < 0.01) and MU firing rates ( R2 = 0.05–0.40, P < 0.05) were associated with anterior-posterior and medio-lateral torque in standing. Our results suggest that the two heads of the gastrocnemius may operate in different ankle ranges with the larger MG being of primary importance when standing, likely due to its fascicle orientation. These differences in MU discharge behavior were independent of the type of descending neural drive, which points to a muscle-specific optimization of triceps surae motoneurons.

Receptor Mechanisms Underlying Heterogenic Reflexes Among the Triceps Surae Muscles of the Cat

1999 ◽  
Vol 81 (2) ◽  
pp. 467-478 ◽  
Author(s):  
T. Richard Nichols
Keyword(s):  
Triceps Surae ◽  
Spinal Reflex ◽  
Medial Gastrocnemius ◽  
Entire Group ◽  
Passive Components ◽  
Mechanical Coupling ◽  
Golgi Tendon Organs ◽  
Reflex Pathways ◽  
Tendon Organs ◽  
Triceps Surae Muscles

Receptor mechanisms underlying heterogenic reflexes among the triceps surae muscles of the cat. The soleus (S), medial gastrocnemius (MG), and lateral gastrocnemius (LG) muscles of the cat are interlinked by rapid spinal reflex pathways. In the decerebrate state, these heterogenic reflexes are either excitatory and length dependent or inhibitory and force dependent. Mechanographic analysis was used to obtain additional evidence that the muscle spindle primary ending and the Golgi tendon organ provide the major contributions to these reflexes, respectively. The tendons of the triceps surae muscles were separated and connected to independent force transducers and servo-controlled torque motors in unanesthetized, decerebrate cats. The muscles were activated as a group using crossed-extension reflexes. Electrical stimulation of the caudal cutaneous sural nerve was used to provide a particularly strong activation of MG and decouple the forces of the triceps surae muscles. During either form of activation, the muscles were stretched either individually or in various combinations to determine the strength and characteristics of autogenic and heterogenic feedback. The corresponding force responses, including both active and passive components, were measured during the changing background tension. During activation of the entire group, the excitatory, heterogenic feedback linking the three muscles was found to be strongest onto LG and weakest onto MG, in agreement with previous results concerning the strengths of heteronymous Ia excitatory postsynaptic potentials among the triceps surae muscles. The inhibition, which is known to affect only the soleus muscle, was dependent on active contractile force and was detected essentially as rapidly as length dependent excitation. The inhibition outlasted the excitation and was blocked by intravenous strychnine. These results indicate that the excitatory and inhibitory effects are dominated by feedback from primary spindle receptors and Golgi tendon organs. The interactions between these two feedback pathways potentially can influence both the mechanical coupling between ankle and knee.

scholarly journals Dry needling of the gastrocnemius muscle. Overlap between trigger point area and the presence of blood vessels

2019 ◽  
Vol 02 (02) ◽  
pp. 063-063
Author(s):  
Velasco Fernández P. ◽  
Valera Garrido F.
Keyword(s):  
Blood Vessels ◽  
Gastrocnemius Muscle ◽  
Trigger Point ◽  
Trigger Points ◽  
Medial Gastrocnemius ◽  
Dry Needling ◽  
Lateral Gastrocnemius ◽  
Myofascial Trigger Points ◽  
Gastrocnemius Muscles ◽  
Venous Pattern

Abstract Aims To evaluate the anatomic variability of the gastrocnemius venous system using ultrasound and the overlap of the same with myofascial trigger points (MTrPs 1 and 2) clinically located in this muscle. Material and Methods In total, 82 legs of 41 healthy adults were studied, belonging to 26 men and 15 women aged between 22 and 50 years. The blood vessels located below MTrP1 and MTrP2, described by Travell and Simons were observed, and each image was analyzed by sectors (medial, central and lateral) to quantify the number of blood vessels, their distribution and overlap with the MTrPs described at this level. Results Examination of the 164 heads of 82 gastrocnemius muscles revealed that at least one vessel exists for each section analyzed. The number of veins per head varied between 1 and 8. The most common pattern in the medial gastrocnemius was three vessels (41.5%) and two vessels (49%) in the lateral gastrocnemius. In 100% of the cases the localization of the veins coincided with the clinical localization of the MTrPs. Conclusions The venous pattern of the proximal gastrocnemius is highly variable among subjects regarding the number of blood vessels and their distribution. There is a complete overlap between the clinical localization of the gastrocnemius MTrPs and the presence of blood vessels.

Beta-contributions to fusimotor action in triceps surae muscles of decerebrated cats

1987 ◽  
Vol 57 (2) ◽  
pp. 574-595 ◽  
Author(s):  
S. E. Grill ◽  
W. Z. Rymer
Keyword(s):  
Muscle Force ◽  
Discharge Rate ◽  
Muscle Spindles ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Gamma Activity ◽  
Response Patterns ◽  
Two Measures ◽  
Triceps Surae Muscles ◽  
Stimulation Of

The discharge of spindle afferents from medial gastrocnemius and soleus muscles was recorded in the decerebrated cat preparation, under isometric conditions and during ramp and hold stretches. Motor output was varied systematically by manual stimulation of the contralateral hindlimb. Twenty-six of 34 afferents showed response patterns consistent with enhancement of dynamic and/or static fusimotor input with increasing muscle force. To establish whether force-related fusimotor effects were mediated at least partly by beta-input, beta-innervation to these same spindles was sought, using a ventral root stimulation protocol. Twenty-three of the 34 afferents were shown to receive beta-innervation, which was most often static in type. For two measures of fusimotor action, the slope of the afferent dynamic rate-length relation and the discharge rate measured during the last portion of ramp stretch, significant increases in the measure, which paralleled increases in muscle force, made it statistically more likely that the afferent received beta-innervation. Our measures did not successfully predict the type of beta-input (beta-static or beta-dynamic). Procaine block of gamma-fibers produced substantial reductions in fusimotor effect in seven spindle afferents (although modest residual fusimotor effects were detectable for 3/7 afferents). The severity of these reductions indicates that beta-action probably requires concurrent gamma-input to the spindle in order to be effective. In support of this possibility, the fusimotor effects of electrical stimulation of single beta-fibers were greatly reduced for five out of six afferents during procaine block of gamma-fibers, compared with the beta-effects recorded when modest levels of spontaneous gamma-activity were present. We conclude that beta-innervation to muscle spindles of triceps surae is common and that this innervation exerts significant fusimotor effects. It appears likely that beta-motoneurons are able to produce both static and dynamic effects above extrafusal threshold, but that the actions require on-going gamma-activity in order to be effective.

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