Quantifying Active and Passive Stiffness in Plantar Flexor Muscles Following Intermittent Maximal Isometric Contractions Using Shear Wave Elastography.

Objective: This study aimed: (i) to investigate the impact of fatigue, triggered by maximal isometric contraction exercises, on the active and passive stiffness of plantar flexors (PF), and (ii) to examine the relationship between changes in mechanical parameters and neuromuscular alterations after fatigue.

Methods: A healthy cohort (n = 12; age = 27.3 ± 5.

The influence of obesity and fat distribution on ankle muscle coactivation during gait.

Background: Excessive body weight is associated with gait alterations. In none of previous studies, body fat distribution has been considered as a factor that could change gait parameters and induce different neuromuscular adaptations.

Objective: This multicenter, analytical, and cross-sectional study aimed to investigate the influence of the body mass distribution on gait parameters and ankle muscle coactivation in obese individuals.

Neuromuscular fatigue in autoimmune myasthenia gravis: A cross-sectional study.

Objectives: To investigate the presence of increased neuromuscular fatigue (NMF) in individuals with myasthenia gravis (IwMG), compared to healthy controls. A secondary aim was to assess associations between NMF, strength and perceived health-related quality of life (HRQoL) and symptom severity in IwMG.

Methods: In this cross-sectional study, we assessed NMF using classical myoelectrical indicators (root mean square: RMS, mean power frequency: MPF) obtained from surface electromyography (sEMG) during a sustained submaximal isometric contraction of the right Biceps Brachii and the right Vastus Lateralis and by evaluating the post-effort decline in peak torque following a fatiguing task consisting of a 40-second sustained isometric contraction.

Free-Living Physical Activity and Sedentary Behaviour in Autoimmune Myasthenia Gravis: A Cross-Sectional Study.

Background: Muscle weakness and fatigability, the prominent symptoms of autoimmune myasthenia gravis (MG), negatively impact daily function and quality of life (QoL). It is currently unclear as to what extent symptoms limit activity and whether physical activity (PA) behaviours are associated with reduced QoL.

Objectives: This study aimed to describe habitual PA patterns and explore relationships between PA metrics, clinical MG characteristics, and health-related QoL (HRQoL).

Surface Electromyography in Physiotherapist Educational Program in France: Enhancing Learning sEMG in Stretching Practice.

Surface electromyography (sEMG) is a non-invasive method, which may be used in France by health practitioners without medical degree, such as physiotherapists, who are taught in Institutes of physiotherapy. However, very few hours are devoted to sEMG teaching in physiotherapist educational programs, especially in a form of practical work. In order to motivate using sEMG in physiotherapy to the students, we propose an example of sEMG practical work, applied to muscle stretching.

Vertical Jump on a Force Plate for Assessing Muscle Strength and Power in Women With Severe Obesity: Reliability, Validity, and Relations With Body Composition.

Bellicha, A, Giroux, C, Ciangura, C, Menoux, D, Thoumie, P, Oppert, J-M, and Portero, P. Vertical jump on a force plate for assessing muscle strength and power in women with severe obesity: reliability, validity, and relations with body composition. J Strength Cond Res 36(1): 75-81, 2022-Muscle strength and power, particularly when assessed during multijoint movements such as vertical jump (VJ), are important predictors of health status and physical function.

Changes in Cardiorespiratory Fitness After Gastric Bypass: Relations with Accelerometry-Assessed Physical Activity.

Background: Exercise training optimizes cardiorespiratory fitness (CRF) after bariatric surgery, but the effect of spontaneous physical activity is not well known. This study aimed to objectively quantify changes in CRF and habitual physical activity 6 months after bariatric surgery and to examine whether change in CRF was related to change in physical activity.

Methods: Secondary analyses were performed on data from women who underwent Roux-en-Y gastric bypass (RYGB) between 2010 and 2014.

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

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.

Marathons and myasthenia gravis: a case report.

Background: The cardinal symptoms of auto-immune myasthenia gravis are fatigue and weakness. Endurance events such as marathon running would seem incompatible with this chronic disease. Many patients stop sport altogether.

The benefits and tolerance of exercise in myasthenia gravis (MGEX): study protocol for a randomised controlled trial.

Background: Research exploring the effects of physical exercise in auto-immune myasthenia gravis (MG) is scarce. The few existing studies present methodological shortcomings limiting the conclusions and generalisability of results. It is hypothesised that exercise could have positive physical, psychological as well as immunomodulatory effects and may be a beneficial addition to current pharmacological management of this chronic disease.

Translation, cross-cultural adaptation, and validation of the french version of the 15-item Myasthenia Gravis Quality Of life scale.

Introduction: Evaluation of quality of life (QOL) has become essential in healthcare. Currently no MG-specific QOL measure exists in French. The aim of this study was to translate, culturally adapt, and evaluate the psychometric properties of the French version of the 15-Item Myasthenia Gravis Quality of Life Scale (MG-QOL15) scale for French myasthenia patients.

Influence of Cervical Muscle Fatigue on Musculo-Tendinous Stiffness of the Head-Neck Segment during Cervical Flexion.

Aim: The aim of this study is to determine if the fatigue of cervical muscles has a significant influence on the head-neck segment musculo-tendinous stiffness.

Methods: Ten men (aged 21.2 ± 1.

Interaction between gastrocnemius medialis fascicle and Achilles tendon compliance: a new insight on the quick-release method.

The insufficient temporal resolution of imaging devices has made the analysis of very fast movements, such as those required to measure active muscle-tendon unit stiffness, difficult. Thus the relative contributions of tendon, aponeurosis, and fascicle to muscle-tendon unit compliance remain to be determined. The present study analyzed the dynamic interactions of fascicle, tendon, and aponeurosis in human gastrocnemius medialis during the first milliseconds of an ankle quick-release movement, using high-frame-rate ultrasonography (2,000 frames/s).

Musculo-tendinous stiffness of head-neck segment in the sagittal plane: an optimization approach for modeling the cervical spine as a single-joint system.

Despite the multi-linked architecture of the cervical spine, all previous studies that have made estimations of mechanical properties of the neck have considered the head-neck segment as a rigid link, with a fixed center of rotation at C7. The aim of this study was to consider the head-neck segment as a changeable geometry system for locating the resultant center of rotation and for calculating the musculo-tendinous stiffness by the quick-release method. Head kinematics during quick-releases was analyzed by recording the trajectory of surface markers.

Neck strength and EMG activity in fighter pilots with episodic neck pain.

Introduction: Neck pain is common in fighter pilots due to repeated exposure to high +Gz loads, but studies comparing neck function in symptomatic and healthy fighter pilots are lacking. This study compared neck strength and EMG activity during maximal isometric contractions in a sitting position in the sagittal and coronal planes in neck pain (SP), asymptomatic fighter pilots (AP), and healthy, male, non-pilot subjects (NPS).

Methods: There were 9 SP, 10 AP, and 8 NPS, all males, who performed maximal isometric neck contractions on a specific dynamometer.

Exploring the effects of kinesiological awareness and mental imagery on movement intention in the performance of demi-plié.

This study was designed to assess the ability of a practitioner intervention using kinesiological explanations and mental imagery techniques to optimize the performance of demi-plié in dancers. Seven professional female ballet dancers were involved in the study. Biomechanical and electromyographical parameters (maximum knee flexion, jump height, maximal vertical acceleration and its duration, ratio of sagittal acceleration variation, and ratio of muscle activity in four muscles of the lower limb) were analyzed before and after the practitioner intervention.

Acute neck pain: cervical spine range of motion and position sense prior to and after joint mobilization.

Despite the relatively high prevalence of cervical spine pain, the efficacy of treatment procedures is limited. In the current study, range of motion and proprioception was assessed prior to and after specific cervical spine mobilisation techniques. A 44-year-old male office worker presented with a history of cervical pain of 1 day duration.

Repeatability of surface EMG parameters at various isometric contraction levels and during fatigue using bipolar and Laplacian electrode configurations.

The objective of this work was to assess the repeatability of two surface electromyographic (sEMG) recording techniques, the classical bipolar configuration and a Laplacian configuration to document their ability to provide reliable information during follow-up studies. The signals were recorded on 10 healthy subjects during voluntary isometric contractions of the biceps brachii muscle at different constant contraction levels. Slopes, area ratios (at 60% of the maximal voluntary contraction (MVC)) and initial values (at 20%, 40%, 60%, 80% and 100% MVC) of the root mean square (RMS), the mean power frequency (MPF) and the muscle fibre conduction velocity (CV) were estimated.

Human muscle hardness assessment during incremental isometric contraction using transient elastography.

The aim of this study was to investigate the relationship between biceps brachii hardness using the transient elastography technique, and its activity level by quantifying the surface electromyographic signal (sEMG). Ten healthy subjects volunteered for this protocol. To assess the maximal biceps brachii myoelectric activity (sEMG-RMSm), subjects had to achieve their maximal voluntary contraction trial during an elbow flexion effort.

Exercise tolerance and daily life in McArdle's disease.

McArdle's disease is a common disorder of muscle metabolism and is due to myophosphorylase deficiency. The major complaint of patients with this disease is effort intolerance. Although the clinical features of affected patients are well known, their daily lifestyle is not well documented.