Effect of muscle length on the modulation of H-reflex and inhibitory mechanisms of Ia afferent discharges during passive muscle lengthening.

The effectiveness of activated Ia afferents to discharge α-motoneurons is decreased during passive muscle lengthening compared with static and shortening muscle conditions. Evidence suggests that these regulations are explained by ) greater postactivation depression induced by homosynaptic postactivation depression (HPAD) and ) primary afferent depolarization (PAD). It remains uncertain whether muscle length impacts the muscle lengthening-related aspect of regulation of the effectiveness of activated Ia afferents to discharge α-motoneurons, HPAD, PAD, and heteronymous Ia facilitation (HF).

The effects of wearing textured versus smooth shoe insoles for 4-weeks in people with diabetic peripheral neuropathy: a randomised controlled trial.

Purpose: To determine whether short-term wear of textured insoles alters balance, gait, foot sensation, physical activity, or patient-reported outcomes, in people with diabetic neuropathy.

Materials And Methods: 53 adults with diabetic neuropathy were randomised to wear textured or smooth insoles for 4-weeks. At baseline and post-intervention, balance (foam/firm surface; eyes open/closed) and walking were assessed whilst barefoot, wearing shoes only, and two insoles (textured/smooth).

The effects of vibrating shoe insoles on standing balance, walking, and ankle-foot muscle activity in adults with diabetic peripheral neuropathy.

Background: Peripheral neuropathy is one of the most common complications of type 2 diabetes, which can lead to impaired balance and walking. Innovative footwear devices designed to stimulate foot sensory receptors, such as vibrating insoles, could offer a new route to improve motor impairments in people with diabetic peripheral neuropathy (DPN).

Research Question: Does wearing vibrating insoles for the first time alter measures of balance, walking, and ankle-foot muscle activity, in people with DPN?

Methods: A randomised cross-over study was conducted with 18 ambulant men and women with a diagnosis of DPN.

Post-activation potentiation after isometric contractions is strongly related to contraction intensity despite the similar torque-time integral.

Post-activation potentiation (PAP) is defined as an enhanced contractile response of a muscle following its own contractile activity and is influenced by the intensity and duration of the conditioning contraction. The aim of this study was to determine if the combination of intensity and duration, that is, torque-time integral (TTI) is a determinant of PAP amplitude. We compared PAP amplitude following low-to-maximal voluntary conditioning contraction intensities with and without similar TTI in the knee extensors.

Horizontal foot orientation affects the distribution of neural drive between gastrocnemii during plantarflexion, without changing neural excitability.

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.

Effects of wearing textured versus smooth shoe insoles for 12 weeks on gait, foot sensation and patient-reported outcomes, in people with multiple sclerosis: a randomised controlled trial.

Background: Innovative shoe insoles, designed to enhance sensory information on the plantar surface of the feet, could help to improve walking in people with Multiple Sclerosis.

Objective: To compare the effects of wearing textured versus smooth insoles, on measures of gait, foot sensation and patient-reported outcomes, in people with Multiple Sclerosis.

Methods: A prospective, randomised controlled trial was conducted with concealed allocation, assessor blinding and intention-to-treat analysis.

Estimates of persistent inward currents in lower limb muscles are not different between inactive, resistance-trained, and endurance-trained young males.

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.

Characterization of neuromuscular performances in adults with late-onset Pompe disease: A control case cross-sectional study.

Adults with late-onset Pompe disease (aLOPD) are characterized by muscular contractile tissue deterioration. However, their neuromuscular performances are poorly known. We aimed to compare maximal muscle strength, activation, explosive strength and neuromuscular fatigue between aLOPD and controls.

Fatigue in elite fencing: Effects of a simulated competition.

The fatigue induced by fencing remains scarcely investigated. We aimed to investigate both objective (neuromuscular performance fatigability) and subjective (perceived fatigue, effort, and workload) manifestations of fatigue in elite fencers following a five-bout simulated competition. Changes in countermovement jump height, knee extensors maximal isometric torque, rate of torque development, voluntary activation, and contractile response to muscular electrical stimulation were measured in 29 elite fencers [12 epee (6 women), 11 saber (5 women), and 6 foil].

Determinants and Characterization of Locomotion in Adults with Late-Onset Pompe Disease: New Clinical Biomarkers.

Background: The late-onset form of Pompe disease (LOPD) is characterized by muscle weakness, locomotor limitations and a risk of falls. The mechanisms responsible for altered locomotion in adults with LOPD are unknown. The identification of clinical biomarkers is essential for clinical follow-up and research.

Motor performance, motor impairments, and quality of life after eccentric resistance training in neurological populations: A systematic review and meta-analyses.

Background: Many overlapping factors impair motor performance and quality of life in neurological patients. Eccentric resistance training (ET) has potential benefits for improving motor performance and treating motor impairments better than some traditional rehabilitation approaches.

Objective: To estimate the effect of ET in neurological settings.

Regulation of primary afferent depolarization and homosynaptic post-activation depression during passive and active lengthening, shortening and isometric conditions.

Purpose: This study aimed to determine whether the modulation of primary afferent depolarization (PAD) and homosynaptic post-activation depression (HPAD) are involved in the lower efficacy of Ia-afferent-α-motoneuron transmission commonly observed during lengthening compared to isometric and shortening conditions.

Methods: 15 healthy young individuals participated in two experimental sessions dedicated to measurement in passive and active muscle states, respectively. In each session, PAD, HPAD and the efficacy of Ia-afferent-α-motoneuron transmission were evaluated during lengthening, shortening and isometric conditions.

Motor Function Characteristics of Adults With Late-Onset Pompe Disease: A Systematic Scoping Review.

Background And Objectives: Pompe disease is a rare neuromuscular disease caused by a deficiency of the lysosomal enzyme acid α-glucosidase. The late-onset Pompe disease (LOPD) in adults is characterized by weakness of ventilatory, axial, and proximal extremity muscles. These muscle impairments progressively impair various motor functions such as locomotion and postural control.

Immediate effects of wearing textured versus smooth insoles on standing balance and spatiotemporal gait patterns when walking over even and uneven surfaces in people with multiple sclerosis.

Purpose: To investigate the immediate effects of wearing novel sensory-stimulating textured insoles on balance and gait in 41 people with multiple sclerosis (pwMS).

Materials And Methods: Assessments of balance (firm/foam surface; eyes open/closed) and walking (when negotiating even/uneven surfaces) were performed wearing textured insoles, smooth insoles, shoes only, and barefoot. Outcome measures were centre of pressure (CoP) movement during standing (elliptical area, sway path velocity) and spatiotemporal gait patterns (stride/step width, stride time, double-limb support time, stride length, velocity).

Acute effect of tendon vibration applied during isometric contraction at two knee angles on maximal knee extension force production.

The aim of the current study was to investigate the effect of a single session of prolonged tendon vibration combined with low submaximal isometric contraction on maximal motor performance. Thirty-two young sedentary adults were assigned into two groups that differed based on the knee angle tested: 90° or 150° (180° = full knee extension). Participants performed two fatigue-inducing exercise protocols: one with three 10 min submaximal (10% of maximal voluntary contraction) knee extensor contractions and patellar tendon vibration (80 Hz) another with submaximal knee extensor contractions only.

Is there an intermuscular relationship in voluntary activation capacities and contractile kinetics?

Purpose: The force-generating capacities of human skeletal muscles are interrelated, highlighting a common construct of limb strength. This study aimed to further determine whether there is an intermuscular relationship in maximal voluntary activation capacities and contractile kinetics of human muscles.

Methods: Twenty-six young healthy individuals participated in this study.

The Physiological Characteristics of an 83-Year-Old Champion Female Master Runner.

Purpose: To examine the cardiorespiratory, muscular, and skeletal characteristics of an 83-year-old champion female master athlete (called DL in this study) who had set multiple world running records in the 80-to-84-year-old age group.

Methods: Measures of maximal oxygen uptake, maximal heart rate, maximal isometric torque for knee extensor muscles, thigh and triceps surae muscle volumes, and bone mineral density (BMD) of the proximal femur region were evaluated. Based on previously published equations, physiological age was determined for maximal oxygen uptake, maximal heart rate, and maximal isometric torque.

A single session of anodal transcranial direct current stimulation applied over the affected primary motor cortex does not alter gait parameters in chronic stroke survivors.

Objectives: The excitability of some neural circuits involved in walking and affected in individuals with chronic stroke can be modulated during and/or immediately after anodal transcranial direct current stimulation (a-tDCS). This study was designed to investigate the effects of a-tDCS during and immediately after application on leg muscle activity during gait, and on spatiotemporal and kinematic gait parameters in patients with chronic stroke.

Methods: This study was randomized, sham-controlled and double-blinded with a cross-over design and included 24 individuals with chronic stroke.

Perceptual Inhibition Is Not a Specific Component of the Sensory Integration Process Necessary for a Rapid Voluntary Step Initiation in Healthy Older Adults.

Objectives: We investigated whether performing step initiation during a proprioceptive perturbation would require greater perceptual or motor inhibitory control in older adults.

Method: Fifty-two healthy adults (young: n = 26, mean age 22.5 years vs.

Neural and muscular factors both contribute to plantar-flexor muscle weakness in older fallers.

Plantar-flexor muscles are key muscles in the control of postural sway. Older fallers present lower maximal plantar-flexor performance than older non-fallers; however, the mechanisms underlying this motor impairment remain to be elucidated. This study aimed to determine whether muscular and neural factors are both involved in the lower maximal plantar-flexor performance of older fallers.

Effect of knee angle on neuromuscular assessment of plantar flexor muscles: A reliability study.

Introduction: This study aimed to determine the intra- and inter-session reliability of neuromuscular assessment of plantar flexor (PF) muscles at three knee angles.

Methods: Twelve young adults were tested for three knee angles (90°, 30° and 0°) and at three time points separated by 1 hour (intra-session) and 7 days (inter-session). Electrical (H reflex, M wave) and mechanical (evoked and maximal voluntary torque, activation level) parameters were measured on the PF muscles.

Effects of neuromuscular electrical stimulation on contralateral quadriceps function.

Because maximal voluntary strength of the knee extensor muscles can be facilitated by the concomitant application of neuromuscular electrical stimulation (NMES) to the contralateral homologous muscle, we aimed to determine whether this was associated with an enhanced neural drive to the agonist muscles. A secondary goal of this study was to examine the potential dose-response relationship between NMES intensity and contralateral facilitation. Twelve healthy men (age: 30 ± 7 yr) completed several maximal voluntary contractions (MVC) of the left knee extensors while the right quadriceps received low-intensity NMES (10% MVC), high-intensity NMES (30% MVC) or no NMES.

Age-related decline in endurance running performance - an example of a multiple World records holder.

This study examined the age-related decline in endurance running performance of one of the greatest master runners ever, Ed Whitlock, who died recently. His running performances from 1500 m to marathon were analyzed for 5 periods of 5 years from 65-69 years to 85-89 years. Despite exceptional running performances for his advanced age, the rate of decline in his performances increased after 80 years and was drastically amplified after 85 years.