Reducing the energy cost of walking in older adults using a passive hip flexion device.

Background: Elevated energy cost is a hallmark feature of gait in older adults. As such, older adults display a general avoidance of walking which contributes to declining health status and risk of morbidity. Exoskeletons offer a great potential for lowering the energy cost of walking, however their complexity and cost often limit their use.

Metabolic cost adaptations during training with a soft exosuit assisting the hip joint.

Different adaptation rates have been reported in studies involving ankle exoskeletons designed to reduce the metabolic cost of their wearers. This work aimed to investigate energetic adaptations occurring over multiple training sessions, while walking with a soft exosuit assisting the hip joint. The participants attended five training sessions within 20 days.

Moderate treadmill run worsened static but not dynamic postural stability of healthy individuals.

Purpose: Running has been demonstrated to be one of the most relevant exercise in altering static postural stability, while limiting attention has been paid to its effects on dynamic postural stability. The aim of the present study was to investigate if 25 min of moderate running on a treadmill altered static and dynamic postural stability in healthy subjects.

Methods: Eight female and six male participants (age 27.

Differences in electromyographic activity of biceps brachii and brachioradialis while performing three variants of curl.

Background: Dumbbell curl (DC) and barbell curl in its two variants, straight (BC) or undulated bar (EZ) are typical exercises to train the elbow flexors. The aim of the study was to verify if the execution of these three variants could induce a selective electromyographic (EMG) activity of the biceps brachii (BB) and brachioradialis (BR).

Methods: Twelve participants performed one set of ten repetitions at 65% of their 1-RM for each variant of curl.

Different intensities of basketball drills affect jump shot accuracy of expert and junior players.

Background: In basketball a maximum accuracy at every game intensity is required while shooting. The aim of the present study was to investigate the acute effect of three different drill intensity simulation protocols on jump shot accuracy in expert and junior basketball players.

Materials & Methods: Eleven expert players (age 26 ± 6 yrs, weight 86 ± 11 kg, height 192 ± 8 cm) and ten junior players (age 18 ± 1 yrs, weight 75 ± 12 kg, height 184 ± 9 cm) completed three series of twenty jump shots at three different levels of exertion.

Lower limb biomechanical analysis during an unanticipated step on a bump reveals specific adaptations of walking on uneven terrains.

Although it is clear that walking over different irregular terrain is associated with altered biomechanics, there is little understanding of how we quickly adapt to unexpected variations in terrain. This study aims to investigate which adaptive strategies humans adopt when performing an unanticipated step on an irregular surface, specifically a small bump. Nine healthy male participants walked at their preferred walking speed along a straight walkway during five conditions: four involving unanticipated bumps of two different heights, and one level walking condition.

Varying negative work assistance at the ankle with a soft exosuit during loaded walking.

Background: Only very recently, studies have shown that it is possible to reduce the metabolic rate of unloaded and loaded walking using robotic ankle exoskeletons. Some studies obtained this result by means of high positive work assistance while others combined negative and positive work assistance. There is no consensus about the isolated contribution of negative work assistance.

Effect of timing of hip extension assistance during loaded walking with a soft exosuit.

Background: Recent advances in wearable robotic devices have demonstrated the ability to reduce the metabolic cost of walking by assisting the ankle joint. To achieve greater gains in the future it will be important to determine optimal actuation parameters and explore the effect of assisting other joints. The aim of the present work is to investigate how the timing of hip extension assistance affects the positive mechanical power delivered by an exosuit and its effect on biological joint power and metabolic cost during loaded walking.

Muscle size explains low passive skeletal muscle force in heart failure patients.

Background: Alterations in skeletal muscle function and architecture have been linked to the compromised exercise capacity characterizing chronic heart failure (CHF). However, how passive skeletal muscle force is affected in CHF is not clear. Understanding passive force characteristics in CHF can help further elucidate the extent to which altered contractile properties and/or architecture might affect muscle and locomotor function.

A biologically-inspired multi-joint soft exosuit that can reduce the energy cost of loaded walking.

Background: Carrying load alters normal walking, imposes additional stress to the musculoskeletal system, and results in an increase in energy consumption and a consequent earlier onset of fatigue. This phenomenon is largely due to increased work requirements in lower extremity joints, in turn requiring higher muscle activation. The aim of this work was to assess the biomechanical and physiological effects of a multi-joint soft exosuit that applies assistive torques to the biological hip and ankle joints during loaded walking.

Soleus Muscle as a Surrogate for Health Status in Human Heart Failure.

We propose the hypothesis that soleus muscle function may provide a surrogate measure of functional capacity in patients with heart failure. We summarize literature pertaining to skeletal muscle as a locus of fatigue and present our recent findings, using in vivo imaging in combination with biomechanical experimentation and modeling, to reveal novel structure-function relationships in chronic heart failure skeletal muscle and gait.

Biomechanical Comparison of Shorts With Different Pads: An Insight into the Perineum Protection Issue.

An intensive use of the bicycle may increase the risk of erectile dysfunction and the compression of the perineal area has been showed to be a major mechanism leading to sexual alterations compromising the quality of life. Manufacturers claim that pads contribute to increase cyclists perineal protection ensuring a high level of comfort. To investigate the influence of various cycling pads with regard to perineal protection and level of comfort.

Ultrasound characterization of medial gastrocnemius tissue composition in children with spastic cerebral palsy.

Introduction: In this study we aimed to characterize muscle composition of the medial gastrocnemius in children with spastic cerebral palsy (SCP) using quantitative ultrasound.

Methods: Forty children with SCP, aged 4-14 years, participated in this study. Children were grouped according to the gross motor function classification system (GMFCS I-V) and compared with a cohort of age- and gender-matched, typically developing children (TD; n = 12).

Gait analysis in chronic heart failure: The calf as a locus of impaired walking capacity.

Reduced walking capacity, a hallmark of chronic heart failure (CHF), is strongly correlated with hospitalization and morbidity. The aim of this work was to perform a detailed biomechanical gait analysis to better identify mechanisms underlying reduced walking capacity in CHF. Inverse dynamic analyses were conducted in CHF patients and age- and exercise level-matched control subjects on an instrumented treadmill at self-selected treadmill walking speeds and at speeds representing +20% and -20% of the subjects' preferred speed.

Is the soleus a sentinel muscle for impaired aerobic capacity in heart failure?

Purpose: Skeletal muscle wasting is well documented in chronic heart failure (CHF). This article provides a more detailed understanding of the morphology behind this muscle wasting and the relation between muscle morphology, strength, and exercise capacity in CHF. We investigated the effect of CHF on lower limb lean mass, detailed muscle-tendon architecture of the individual triceps surae muscles (soleus (SOL), medial gastrocnemius, and lateral gastrocnemius) and how these parameters relate to exercise capacity and strength.

Comparative evaluation of two skiing simulators as functional training devices for recreational skiers.

The aims of this study were to examine two ski simulators, Skimagic and Skier's Edge, and to evaluate their efficacy as functional training devices for skiers. Vertical ground reaction forces, knee flexion angle kinematics and muscles activity were recorded on these devices and compared with those measured in similar condition while skiing on snow. Five ski instructors performed three randomized testing sessions (snow, Skimagic and Skier's Edge).

Soleus fascicle length changes are conserved between young and old adults at their preferred walking speed.

Older adults have been shown to naturally select a walking speed approximately 20% slower than younger adults. We explored the possibility that a reduction in preferred speed in older adults represents a strategy to preserve the mechanical function of the leg muscles. We examined this question in the soleus muscle in eight healthy young (25.