gastrocnemius medialis

CONTEXT: Anterior cruciate ligament injuries are directly related to the control of dynamic knee valgus in the landing of a jump, and this is mainly due to the correct activation and neuromuscular function of the lower-extremity muscles. The aim of the study is to assess the relationship between lower limb muscle activity during a single-legged drop jump and knee frontal plane projection angle (FPPA). DESIGN: A correlation study. METHODS: Thirty healthy collegiate female athletes were included in the study...

Acetylcarnitine is an essential metabolite for maintaining metabolic flexibility and glucose homeostasis. The in vivo behavior of muscle acetylcarnitine content during exercise has not been shown with magnetic resonance spectroscopy. Therefore, this study aimed to explore the behavior of skeletal muscle acetylcarnitine during rest, plantar flexion exercise, and recovery in the human gastrocnemius muscle under aerobic conditions. Ten lean volunteers and nine overweight volunteers participated in the study. A 7 T whole-body MR system with a double-tuned surface coil was used to acquire spectra from the gastrocnemius medialis...

INTRODUCTION: The purpose of this study was to investigate inter- and intra-rater reliability as well as the inter-rater interpretation error of ultrasound measurements assessing skeletal muscle architecture and tissue organization of the gastrocnemius medialis (GM) and vastus lateralis (VL) muscle. METHODS: The GM and VL of 13 healthy adults (22 ± 3 years) were examined thrice with sagittal B-mode ultrasound: intraday test-retest examination by one investigator (intra-rater) and separate examinations by two investigators (inter-rater)...

This study investigated the validity of using OpenSim to measure muscle-tendon unit (MTU) length of the bi-articular lower limb muscles in several postures (shortened, lengthened, a combination of shortened and lengthened involving both joints, neutral and standing) using 3D freehand ultrasound (US), and to propose new personalized models. MTU length was measured on 14 participants and 6 bi-articular muscles (semimembranosus SM, semitendinosus ST, biceps femoris BF, rectus femoris RF, gastrocnemius medialis GM and gastrocnemius lateralis GL), considering 5 to 6 postures...

OBJECTIVE: Skeletal muscles are organized into distinct layers and exhibit anisotropic characteristics across various scales. Assessing the arrangement of skeletal muscles may provide valuable biomarkers for diagnosing muscle-related pathologies and evaluating the efficacy of clinical interventions. APPROACH: In this study, we propose a novel ultrafast ultrasound sequence constituted of steered pushing beams was proposed for ultrasound elastography applications in transverse isotropic muscle...

PURPOSE: The medial approach to the popliteal artery has been less commonly used than the posterior approach in surgical repair of traumatic popliteal injury. This study was performed to quantitatively evaluate the visual field of the popliteal artery obtained by staged myotendotomy in the medial approach to the popliteal artery. METHODS: Twenty legs of fresh-frozen adult cadavers were dissected using the medial approach to the popliteal artery. In stage 1, the popliteal artery was exposed between the vastus medialis and sartorius muscles without myotendotomy...

BACKGROUND: This study aimed to determine the optimal time point, either 30 or 60 minutes, at which muscle reactivity to caffeine administration is highest. Unlike previous studies that focused on the nervous system response, we employed tensiomyography (TMG) to directly assess the effects of caffeine on muscle fibers. METHODS: TMG measurements were performed on the gastrocnemius medialis muscle of 42 male athletes who regularly consumed caffeine. Participants received a dose of 6 mg/kg body weight and TMG measurements were taken prior to caffeine intake, as well as 30 and 60 minutes afterward...

PURPOSE: Muscle mechanics is paramount in our understanding of motor performance. However, little is known regarding the sensitivity of fascicle dynamics and connective tissues stiffness to exercise duration and ambient temperature during running, both increasing muscle temperature. This study aimed to determine gastrocnemius medialis (GM) fascicle dynamics in vivo during running in temperate and hot conditions, as well as muscle-tendon unit responses. METHODS: Using ultrafast ultrasound, fifteen participants (8 men, 7 women, 26 ± 3 years) were tested before, during (2 and 40 min) and after a running task (40 min at 10 km...

Carnosine, an MR-visible dipeptide in human muscle, is well characterized by two peaks at ~8 and ~7 ppm from C2 and C4 imidazole protons. Like creatine and other metabolites, carnosine is subject to residual dipolar coupling in the anisotropic environment of muscle fibers, but the effects have not been studied extensively. Single-voxel TE 30-32 PRESS spectra from three different 3T studies were acquired from gastrocnemius medialis and soleus muscles in the human lower leg. In these studies, carnosine T2 values were measured, and spectra were obtained at three different foot angles...

The distribution of activation among muscles from the same anatomical group can be affected by the mechanical constraints of the task, such as limb orientation. For example, the distribution of activation between the gastrocnemius medialis (GM) and lateralis (GL) muscles during submaximal plantarflexion depends on the orientation of the foot in the horizontal plane. The neural mechanisms behind these modulations are not known. The overall aim of this study was to determine whether the excitability of the two gastrocnemius muscles is differentially affected by changes in foot orientation...

INTRODUCTION: Gait disorders are a major cause of disability and reduced health-related quality of life in people with multiple sclerosis (pwMS). Dry needling (DN) has demonstrated positive results to improve gait parameters in patients with stroke. The main aim of this study was to evaluate the effect of a single session of DN in the gait performance of pwMS. METHODS: A double-blind parallel randomized sham-controlled pilot trial was conducted. Study participants received a single session of active DN or sham DN in the gastrocnemius medialis muscle...

BACKGROUND: Recently we reported the design and evaluation of floating semi-implantable devices that receive power from and bidirectionally communicate with an external system using coupling by volume conduction. The approach, of which the semi-implantable devices are proof-of-concept prototypes, may overcome some limitations presented by existing neuroprostheses, especially those related to implant size and deployment, as the implants avoid bulky components and can be developed as threadlike devices...

BACKGROUND: Missense VCP gene variants lead to a disruption in protein homeostasis causing a spectrum of progressive degenerative diseases. Myopathy is the most frequent manifestation characterized by slowly progressing weakness of proximal and distal limb muscles. We present a family with myopathy due to c.277C > T variant in VCP gene. CASE PRESENTATION: The patient's phenotype includes symmetrical muscle wasting and weakness in the proximal parts of the limbs and axial muscles, a wide based gait, lordotic posture, positive Gowers' sign, mild calf enlargement, impaired mobility, elevated CK, and myopathy in proximal limb muscles...

BACKGROUND: Vascularized nerve grafts (VNGs) have been proposed as a superior alternative to free nerve grafts (FNGs) for complex nerve defects. A greater regenerative potential has been suggested by clinical and experimental studies, but conclusive evidence is still lacking. METHODS: In this experimental study, 10 adult male Wistar rats received a non-vascularized orthotopic sciatic nerve graft on their right side, and a vascularized orthotopic sciatic nerve graft nerve on their left side...

BACKGROUND: Sarcopenia and malnutrition are commonly seen and fundamental indicators of prognosis, and are directly associated with increased mortality in maintenance hemodialysis (MHD) patients. We aimed to reveal the frequency of malnutrition and sarcopenia in patients undergoing MHD and investigate the role of muscle ultrasound (US) parameters to predict sarcopenia and malnutrition. METHODS: A total of 45 patients who have undertaken MHD for more than 6 months three times a week were evaluated for the present study...

Persistent inward currents (PICs) increase the intrinsic excitability of α-motoneurons. The main objective of this study was to compare estimates of α-motoneuronal PICs between inactive, chronic resistance-trained and chronic endurance-trained young individuals. We also aimed to investigate whether there is a relationship in the estimates of α-motoneuronal PIC magnitude between muscles. Estimates of PIC magnitude were obtained in three groups of young individuals: resistance-trained (n=12), endurance-trained (n=12), and inactive (n=13)...

Background: By directly recording electromyographic activity profiles and muscle-tendon interaction, this study aimed to elucidate the mechanisms why well-trained track and field athletes (experts) are able to outperform untrained individuals without former systematic experience in reactive jump training (novices). In particular, reactive power output and the elastic recoil properties of the muscle-tendon unit (MTU) were of special interest. For this purpose, stiffness regulation on muscle and joint level, energy management in terms of storing or dissipating elastic energy were compared between experts and novices during various stretch loads...

Piatnitzkysauridae were Jurassic theropods that represented the earliest diverging branch of Megalosauroidea, being one of the earliest lineages to have evolved moderate body size. This clade's typical body size and some unusual anatomical features raise questions about locomotor function and specializations to aid in body support; and other palaeobiological issues. Biomechanical models and simulations can illuminate how extinct animals may have moved, but require anatomical data as inputs. With a phylogenetic context, osteological evidence, and neontological data on anatomy, it is possible to infer the musculature of extinct taxa...

OBJECTIVE: To analyze the changes in muscle mass and quality with time on the paretic and non-paretic sides in subacute stroke patients and identify correlations between the variation of muscle mass and quality and lower limb functions. METHODS: Thirty hemiplegia patients diagnosed with stroke participated in this study. To evaluate poststroke muscle changes, longitudinal measurement of muscle mass and quality was conducted with bilateral lower limbs. The elastic shear modulus was measured using shear wave elastography and muscle thickness (MT) of rectus femoris, vastus intermedius, vastus lateralis (VL), vastus medialis, tibialis anterior, and gastrocnemius (GCM) muscles...

Objective: To quantify the effects of increasing the step length of the split squat on changes in kinematics, kinetics, and muscle activation of the lower extremity. Methods: Twenty male college students participated in the test (age: 23.9 ± 3.7, height: 175.1 ± 4.9). Data on kinematics, kinetics, and EMG were collected during split squat exercise at four different step lengths in a non-systematic manner. One-way repeated measurements ANOVA were used to compare characteristic variables of peak angle, moment, and RMS among the four step length conditions...