Effects of an occupational soft-back exoskeleton during order picking: a field study in logistics.

The use of exoskeletons is increasingly considered as a solution to reduce workers' exposure to physical risk factors, such as low-back disorders. The aim of this study was to evaluate the effects of the CORFOR occupational soft-back exoskeleton on trunk muscle activity and kinematics during an order picking manual task performed in the field. 10 workers, with at least 4 weeks' experience using the exoskeleton, performed a 1.

Effects of a soft back exoskeleton on lower lumbar spine loads during manual materials handling: a musculoskeletal modelling study.

The aim of this study was to append a passive soft back exoskeleton to a validated musculoskeletal model and assess its effectiveness in reducing lumbar loads. Fifteen participants lifted a box, with and without wearing a CORFOR exoskeleton. A full body OpenSim model was used to estimate lumbar joint moments and reaction forces, as well as low back muscles forces.

The stroke rate influences performance, technique and core stability during rowing ergometer.

The aim of this study is to determine the effect of stroke rate on performance, technique and core stability during rowing ergometer. Twenty-four high-level rowers performed maximal intensity one-minute bouts at 20, 28 and 34 spm on a RowPerfect3 ergometer. Power at the handle, legs, trunk and arms levels were determined, and core kinematics and neuromuscular activations were measured.

Biomechanical Consequences of Using Passive and Active Back-Support Exoskeletons during Different Manual Handling Tasks.

The aim of this study was to assess, for both men and women, the consequences of using different back-support exoskeletons during various manual material tasks (MMH) on the activity of back muscles and trunk kinematics. Fifteen men and fourteen women performed MMH involving a 15 kg load (a static task, a symmetric lifting task, and an asymmetric lifting task). Four exoskeleton conditions were tested: without equipment (CON) and with three exoskeletons passive (P-EXO), and active (A-EXO1 and A-EXO2)).

Characterizing the effects of an ergonomic handle on upper limbs kinematics and neuromuscular activity, comfort, and performance during ergometer rowing.

Articular stress and discomfort during repetitive movements may impact the risk of injuries of the upper limbs during ergometer rowing, especially when using a regular circular handle. Therefore, the purpose of the study was to propose and evaluate the influence of an ergonomic handle on upper limbs biomechanics, comfort and performance during ergometer rowing. An ergonomic irregular hexagon handle, with a 1:1.

Prediction of rowing ergometer performance by technical and core stability parameters.

The purpose of this study was to evaluate the influence of technical and core stability parameters on rowing ergometer performance defined as mean power at the handle. Twenty-four high-level rowers were evaluated at their competitive stroke rate on an instrumented RowPerfect 3 ergometer to determine leg, trunk and arm power output, while trunk and pelvis 3D kinematics were measured. Linear mixed models revealed that mean power at the handle was predicted by the power output of legs, trunk and arms (r = 0.

Is There a Sex Difference in Trunk Neuromuscular Control among Recreational Athletes during Cutting Maneuvers?

Trunk motion is most likely to influence knee joint injury risk, but little is known about sex-related differences in trunk neuromuscular control during changes of direction. The purpose of the present study was to test whether differences in trunk control between males and females during changes of direction exist. Twelve female and 12 male recreational athletes (with at least 10 years of experience in team sport) performed unanticipated changes of direction with 30° and 60° cut angles, while 3D trunk and leg kinematics, ground reaction forces and trunk muscles electromyography were recorded.

Influence of sidestepping expertise and core stability on knee joint loading during change of direction.

The aims of this study were twofold: first, to compare core stability and knee joint loading between sidestepping experts and nonexperts; secondly, to determine core predictors of knee joint loading. Thirteen handball male players (experts) and 14 karatekas (nonexperts) performed six unanticipated 45° sidestepping manoeuvers, while trunk and pelvis 3D kinematics as well as ground reaction forces were measured, and peak knee abduction moment (PKAM) was determined. Student t-tests enabled a comparison of both groups and a linear mixed model approach was used to identify PKAM predictors.

The trunk's contribution to postural control under challenging balance conditions.

Background: The double inverted pendulum model is imprecise when applied to studies of postural control. Although multijoint analyses have improved our understanding of how balance is maintained, the exact role of the trunk remains unclear.

Research Questions: What is the trunk's contribution in postural control with respect to the other joints and how do trunk muscles control trunk kinematics?

Methods: Thirty-six healthy athletes (handball, karate, long jump) performed a highly challenging balance task while the ground support was dynamically tilted in the sagittal plane.

Influence of a Functional Core Stability Program on Trunk and Knee Joint Biomechanics in Female Athletes During Lateral Movements.

Mornieux, G, Weltin, E, Friedman, C, Pauls, M, Forsythe, S, and Gollhofer, A. Influence of a functional core stability program on trunk and knee joint biomechanics in female athletes during lateral movements. J Strength Cond Res 35(10): 2713-2719, 2021-Trunk positioning has been shown to be associated with knee joint loading during athletic tasks, especially changes of direction.

Multimodal assessment of sensorimotor shoulder function in patients with untreated anterior shoulder instability and asymptomatic handball players.

Background: Functional evaluation of sensorimotor function of the shoulder joint is important for guidance of sports-specific training, prevention and rehabilitation of shoulder instability. Such assessment should be multimodal and comprise all qualities of sensorimotor shoulder function. This study evaluates feasibility of such multimodal assessment of glenohumeral sensorimotor function in patients with shoulder instability and handball players.

Influence of a Full-Body Compression Suit on Trunk Positioning and Knee Joint Mechanics During Lateral Movements.

Trunk positioning has been shown to be associated with knee joint loading during athletic tasks, especially changes of direction. The purpose of the present study was to test whether a full-body compression suit (FBCS) would improve trunk positioning and knee joint control during lateral movements. Twelve female athletes performed lateral reactive jumps (LRJ) and unanticipated cuttings with and without the customized FBCS, while 3D kinematics and kinetics were measured.

Effect of gender on trunk and pelvis control during lateral movements with perturbed landing.

In lateral reactive movements, core stability may influence knee and hip joint kinematics and kinetics. Insufficient core stabilisation is discussed as a major risk factor for anterior cruciate ligament (ACL) injuries. Due to the higher probability of ACL injuries in women, this study concentrates on how gender influences trunk, pelvis and leg kinematics during lateral reactive jumps (LRJs).

Anticipatory postural adjustments during cutting manoeuvres in football and their consequences for knee injury risk.

Anticipatory postural adjustments (APAs), i.e. preparatory positioning of the head, the trunk and the foot, are essential to initiate cutting manoeuvres during football games.

Changes in leg kinematics in response to unpredictability in lateral jump execution.

Lateral movements like cutting are essential in many team sport disciplines. The aim of the present study was to analyse adaptations in motor control in response to task unpredictability during lateral movement execution. Twelve subjects performed lateral jumps with different landing modalities (stable, sliding or counteracting) that were either known (predictable setting) or unknown (unpredictable setting) prior to movement execution.

Medial compressible forefoot sole elements reduce ankle inversion in lateral SSC jumps.

Sideward movements are associated with high incidences of lateral ankle sprains. Special shoe constructions might be able to reduce these injuries during lateral movements. The purpose of this study was to investigate whether medial compressible forefoot sole elements can reduce ankle inversion in a reactive lateral movement, and to evaluate those elements' influence on neuromuscular and mechanical adjustments in lower extremities.

Task-specific initial impact phase adjustments in lateral jumps and lateral landings.

Load-dependant adjustments in lateral jumps are thought to rely on foot placement and on upper leg's kinematic and neuromuscular adaptations. The aim of this study was to elucidate task-specific adjustments during the initial impact phase under varying stretch-loads by the comparison of lateral jumps and lateral landings. Ten subjects performed lateral jumps and landings from four distances.

Load-dependent movement regulation of lateral stretch shortening cycle jumps.

The classical stretch shortening cycle (SSC) describes sagittal joint flexion-extensions in motions like running or hopping. However, lateral movements are integral components of team sports and are associated with frontal plane joint displacements. The purpose of this study is to identify neuromuscular and kinematical mechanisms determining motor control and performance of reactive laterally conducted SSCs.

Timing of muscle activation of the lower limbs can be modulated to maintain a constant pedaling cadence.

This study investigated changes in muscle activity when subjects are asked to maintain a constant cadence during an unloaded condition. Eleven subjects pedaled for five loaded conditions (220 W, 190 W, 160 W, 130 W, 100 W) and one unloaded condition at 80 rpm. Electromyographic (EMG) activity of six lower limb muscles, pedal forces and oxygen consumption were calculated for every condition.

Influence of cadence, power output and hypoxia on the joint moment distribution during cycling.

The purpose of this study was to use a hypoxic stress as a mean to disrupt the normal coordinative pattern during cycling. Seven male cyclists pedalled at three cadence (60, 80, 100 rpm) and three power output (150, 250, 350 W) conditions in normoxia and hypoxia (15% O2). Simultaneous measurements of pedal force, joint kinematics, % oxyhaemoglobin saturation, and minute ventilation were made for each riding condition.

Stiffness adaptations in shod running.

When mechanical parameters of running are measured, runners have to be accustomed to testing conditions. Nevertheless, habituated runners could still show slight evolutions of their patterns at the beginning of each new running bout. This study investigated runners' stiffness adjustments during shoe and barefoot running and stiffness evolutions of shoes.

Relationship between the increase of effectiveness indexes and the increase of muscular efficiency with cycling power.

We determined the index of effectiveness (IE), as defined by the ratio of the tangential (effective force) to the total force applied on the pedals, using a new method proposed by Mornieux et al. (J Biomech, 2005), while simultaneously measuring the muscular efficiency during sub-maximal cycling tests of different intensities. This allowed us to verify whether part of the changes in muscular efficiency could be explained by a better orientation of the force applied on the pedals.

A cycle ergometer mounted on a standard force platform for three-dimensional pedal forces measurement during cycling.

This report describes a new method allowing to measure the three-dimensional forces applied on right and left pedals during cycling. This method is based on a cycle ergometer mounted on a force platform. By recording the forces applied on the force platform and applying the fundamental mechanical equations, it was possible to calculate the instantaneous three-dimensional forces applied on pedals.