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 Differences in Plantar Flexor Fascicle Length and Pennation Angle between Healthy and Poststroke Individuals and Implications for Poststroke Plantar Flexor Force Contributions

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
John W. Ramsay ◽  
Thomas S. Buchanan ◽  
Jill S. Higginson
Keyword(s):  
Pennation Angle ◽  
Medial Gastrocnemius ◽  
Plantar Flexor ◽  
Flexor Muscle ◽  
Fascicle Length ◽  
Cross Sectional ◽  
Lateral Gastrocnemius ◽  
Relative Contribution ◽  
Muscle Fascicle ◽  
The Individual

Poststroke plantar flexor muscle weakness has been attributed to muscle atrophy and impaired activation, which cannot collectively explain the limitations in force-generating capability of the entire muscle group. It is of interest whether changes in poststroke plantar flexor muscle fascicle length and pennation angle influence the individual force-generating capability and whether plantar flexor weakness is due to uniform changes in individual muscle force contributions. Fascicle lengths and pennation angles for the soleus, medial, and lateral gastrocnemius were measured using ultrasound and compared between ten hemiparetic poststroke subjects and ten healthy controls. Physiological cross-sectional areas and force contributions to poststroke plantar flexor torque were estimated for each muscle. No statistical differences were observed for any muscle fascicle lengths or for the lateral gastrocnemius and soleus pennation angles between paretic, nonparetic, and healthy limbs. There was a significant decrease (P<0.05) in the paretic medial gastrocnemius pennation angle compared to both nonparetic and healthy limbs. Physiological cross-sectional areas and force contributions were smaller on the paretic side. Additionally, bilateral muscle contributions to plantar flexor torque remained the same. While the architecture of each individual plantar flexor muscle is affected differently after stroke, the relative contribution of each muscle remains the same.

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.

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 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.

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.

scholarly journals Ultrasound Structural Changes in Triceps Surae After a 1-Year Daily Self-stretch Program: A Prospective Randomized Controlled Trial in Chronic Hemiparesis

2019 ◽  
Vol 33 (4) ◽  
pp. 245-259 ◽  
Author(s):  
Maud Pradines ◽  
Mouna Ghedira ◽  
Raphaël Portero ◽  
Ingrid Masson ◽  
Christina Marciniak ◽  
...  
Keyword(s):  
Structural Changes ◽  
Controlled Trial ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Plantar Flexors ◽  
Fascicle Length ◽  
Rehabilitation Programs ◽  
Lower Limb Muscles ◽  
Muscle Fascicle ◽  
Prospective Randomized Controlled Trial

Introduction. The effects of long-term stretching (>6 months) in hemiparesis are unknown. This prospective, randomized, single-blind controlled trial compared changes in architectural and clinical parameters in plantar flexors of individuals with chronic hemiparesis following a 1-year guided self-stretch program, compared with conventional rehabilitation alone. Methods. Adults with chronic stroke-induced hemiparesis (time since lesion >1 year) were randomized into 1 of 2, 1-year rehabilitation programs: conventional therapy (CONV) supplemented with the Guided Self-rehabilitation Contract (GSC) program, or CONV alone. In the GSC group, specific lower limb muscles, including plantar flexors, were identified for a diary-based treatment utilizing daily, high-load, home self-stretching. Blinded assessments included (1) ultrasonographic measurements of soleus and medial gastrocnemius (MG) fascicle length and thickness, with change in soleus fascicle length as primary outcome; (2) maximum passive muscle extensibility (XV1, Tardieu Scale); (3) 10-m maximal barefoot ambulation speed. Results. In all, 23 individuals (10 women; mean age [SD], 56 [±12] years; time since lesion, 9 [±8] years) were randomized into either the CONV (n = 11) or GSC (n = 12) group. After 1 year, all significant between-group differences favored the GSC group: soleus fascicle length, +18.1mm [9.3; 29.9]; MG fascicle length, +6.3mm [3.5; 9.1]; soleus thickness, +4.8mm [3.0; 7.7]; XV1 soleus, +4.1° [3.1; 7.2]; XV1 gastrocnemius, +7.0° [2.1; 11.9]; and ambulation speed, +0.07m/s [+0.02; +0.16]. Conclusions. In chronic hemiparesis, daily self-stretch of the soleus and gastrocnemius over 1 year using GSC combined with conventional rehabilitation increased muscle fascicle length, extensibility, and ambulation speed more than conventional rehabilitation alone.

Monosynaptic EPSPs in primate lumbar motoneurons

1993 ◽  
Vol 70 (4) ◽  
pp. 1585-1592 ◽  
Author(s):  
J. S. Carp
Keyword(s):  
Input Resistance ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Macaca Nemestrina ◽  
Synaptic Connectivity ◽  
Lateral Gastrocnemius ◽  
Mean Values ◽  
Epsp Amplitude ◽  
The Mean ◽  
Stimulation Of

1. Homonymous and heteronymous monosynaptic composite excitatory postsynaptic potentials (EPSPs) were evaluated by intracellular recordings from 89 motoneurons innervating triceps surae (n = 59) and more distal (n = 30) muscles in 14 pentobarbital-anesthetized monkeys (Macaca nemestrina). 2. Homonymous EPSPs were found in all motoneurons tested. The mean values +/- SD for maximum EPSP amplitude of triceps surae motoneurons were 2.5 +/- 1.3, 1.8 +/- 1.3 and 4.5 +/- 2.0 mV for medial gastrocnemius, lateral gastrocnemius, and soleus motoneurons, respectively. Heteronymous EPSPs were almost always smaller than their corresponding homonymous EPSPs. 3. Triceps surae EPSP amplitude was larger in motoneurons with higher input resistance. However, this relationship was weak, suggesting that factors related to input resistance play a limited role in determining the magnitude of the EPSP. 4. The mean ratio +/- SD of the amplitude of the EPSP elicited by combined stimulation of all triceps surae nerves to the amplitude of the algebraic sum of the three individual EPSPs was 0.95 +/- 0.05. This ratio was greater in motoneurons with lower rheobase. 5. Some patterns of synaptic connectivity in the macaque are consistent with previously reported differences between primates and cat (e.g., heteronymous EPSPs elicited by medial gastrocnemius nerve stimulation in soleus motoneurons are small in macaque and other primates but large in cat). However, no overall pattern emerges from a comparison of the similarities and differences in EPSPs among species in which they have been studied (i.e., macaque, baboon, and cat). That is, there are no two species in which EPSP properties are consistently similar to each other, but different from those of the third species.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Effects of muscle action type on corticospinal excitability and triceps surae muscle-tendon mechanics

2018 ◽  
Vol 119 (2) ◽  
pp. 563-572 ◽  
Author(s):  
P. Valadão ◽  
S. Kurokawa ◽  
T. Finni ◽  
J. Avela
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Motor Control ◽  
Pennation Angle ◽  
H Reflex ◽  
Corticospinal Excitability ◽  
Triceps Surae ◽  
Fascicle Length ◽  
The Central Nervous System ◽  
Muscle Actions

This study investigated whether the specific motor control strategy reported for eccentric muscle actions is dependent on muscle mechanical behavior. Motor evoked potentials, Hoffman reflex (H-reflex), fascicle length, pennation angle, and fascicle velocity of soleus muscle were compared between isometric and two eccentric conditions. Ten volunteers performed maximal plantarflexion trials in isometric, slow eccentric (25°/s), and fast eccentric (100°/s) conditions, each in a different randomized testing session. H-reflex normalized by the preceding M wave (H/M) was depressed in both eccentric conditions compared with isometric ( P < 0.001), while no differences in fascicle length and pennation angle were found among conditions. Furthermore, although the fast eccentric condition had greater fascicle velocity than slow eccentric ( P = 0.001), there were no differences in H/M. There were no differences in motor evoked potential size between conditions, and silent period was shorter for both eccentric conditions compared with isometric ( P = 0.009). Taken together, the present results corroborate the hypothesis that the central nervous system has an unique activation strategy during eccentric muscle actions and suggest that sensory feedback does not play an important role in modulating these muscle actions. NEW & NOTEWORTHY The present study provides new insight into the motor control of eccentric muscle actions. It was demonstrated that task-dependent corticospinal excitability modulation does not seem to depend on sensory information processing. These findings support the hypothesis that the central nervous system has a unique activation strategy during eccentric muscle actions.

Skeletal muscle architectural adaptations to marathon run training

2015 ◽  
Vol 40 (1) ◽  
pp. 99-102 ◽  
Author(s):  
Kevin Murach ◽  
Cory Greever ◽  
Nicholas D. Luden
Keyword(s):  
Skeletal Muscle ◽  
Vastus Lateralis ◽  
Pennation Angle ◽  
Fascicle Length ◽  
Lateral Gastrocnemius ◽  
Marathon Training ◽  
Architectural Features ◽  
Before And After ◽  
Recreational Runners ◽  
Lactate Levels

We assessed lateral gastrocnemius (LG) and vastus lateralis (VL) architecture in 16 recreational runners before and after 12 weeks of marathon training. LG fascicle length decreased 10% while pennation angle increased 17% (p < 0.05). There was a significant correlation between diminished blood lactate levels and LG pennation angle change (r = 0.90). No changes were observed in VL. This is the first evidence that run training can modify skeletal muscle architectural features.

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