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Centre of mass during walk or gait

Katherine A J Daniels, J F Burn
It is generally accepted that animals move in a way that minimises energy use during regular gait and there is evidence that the principle might extend more generally to locomotor behaviour and manoeuvres. Jumping during locomotion is a useful manoeuvre that contributes to the versatility of legged locomotion and is within the repertoire of many terrestrial animals. We describe a simple ballistic model that can be used to identify a single unique trajectory of the body's centre of mass that minimises the mechanical work to initiate a jump, regardless of the approach velocity or take-off position...
March 12, 2018: Journal of Experimental Biology
Davy Laroche, Morgane Mangin, Delphine Besson, Alexandre Naaim, Anaïs Gouteron, Jean-Marie Casillas
BACKGROUND: Although the initial anaerobic component of exercise adaptation is unavoidable, no specific functional test is available for use in routine non-sporting practice to evaluate it. OBJECTIVE: To assess the bioenergetic and biomechanical properties of the Short and Fast Step Test (SFST), which consists of walking up and down a step as many times as possible in 1minute and to analyse its ability to explore the initial anaerobic component of effort in comparison to a reference self-paced step test...
February 19, 2018: Annals of Physical and Rehabilitation Medicine
Christian Murer, Lars Christian Huber, Thomas Kurowski, Astrid Hirt, Cécile A Robinson, Urs Bürgi, Christian Benden
AIMS OF THE STUDY: Cystic fibrosis is the most common genetic disorder in Caucasians. The combination of the cystic fibrosis transmembrane conductance regulator (CFTR) corrector lumacaftor / potentiator ivacaftor (LUM/IVA) has been shown to increase forced expiratory volume in 1 second (FEV1) moderately, but predominantly reduce acute exacerbation rate (AER) in Phe508del homozygous cystic fibrosis patients; however, patients with FEV1 <40% predicted were excluded from studies. We used LUM/IVA on a "compassionate use" basis in cystic fibrosis patients with end-stage pulmonary disease...
February 16, 2018: Swiss Medical Weekly
Sébastien Sanges, Jonathan Giovannelli, Vincent Sobanski, Sandrine Morell-Dubois, Hélène Maillard, Marc Lambert, Céline Podevin, Nicolas Lamblin, Pascal De Groote, Jean-François Bervar, Thierry Perez, Régis Matran, Martine Rémy-Jardin, Pierre-Yves Hatron, Éric Hachulla, David Launay
BACKGROUND: There is an ongoing debate regarding the relevance of the 6-minute walking distance (6MWD) in systemic sclerosis (SSc) assessment, widely used as a usual test in these patients as well as an outcome measure in clinical trials. In this work, we aimed to assess the associations between the 6MWD and various disease parameters in patients with SSc. METHODS: Consecutive patients followed in our SSc National Reference Centre were included in this cross-sectional study if they fulfilled the 2013 American College of Rheumatology/European League Against Rheumatism criteria for SSc...
December 15, 2017: Arthritis Research & Therapy
M Geiger, A Supiot, R Zory, P Aegerter, D Pradon, N Roche
BACKGROUND: Following stroke, patients are often left with hemiparesis that reduces balance and gait capacity. A recent, non-invasive technique, transcranial direct current stimulation, can be used to modify cortical excitability when used in an anodal configuration. It also increases the excitability of spinal neuronal circuits involved in movement in healthy subjects. Many studies in patients with stroke have shown that this technique can improve motor, sensory and cognitive function...
October 23, 2017: Trials
Monaco Vito, Tropea Peppino, Lucio A Rinaldi, Micera Silvestro
This study aimed at investigating the organization of joint angle variability during walking by using the uncontrolled manifold (UCM) theory. We tested two hypotheses: i. the coordinative mechanism underlying joint angle variance during the stance phase is compatible with a kinematic synergy that stabilizes the centre of mass (CoM) position; ii. the walking speed affects the variance components onto and orthogonal to the UCM. Eight healthy subjects (26.0±2.0years old) steadily walked on a treadmill at five normalised speeds (from 0...
September 19, 2017: Human Movement Science
Qipeng Song, Jingyi Zhou, Wei Sun, Cui Zhang, Houxin Gu, Dewei Mao
The effects of long-term Tai Chi exercise on body stability of the elderly during stair ascent under high and low illumination were investigated. Forty-five healthy elderly women were divided into three groups, namely, Tai Chi exercise group, brisk walking group and no-exercise control group. All the participants ascended a staircase, during which force platforms and a motion capture system collected the data. Under the high illumination, Tai Chi exercise participants exhibited higher loading rate and anteroposterior centre of pressure (COPap) displacement as well as a lower braking impulse than no-exercise group...
September 7, 2017: Sports Biomechanics
Gwenllian Fflur Tawy, Philip Rowe, Leela Biant
Knee osteoarthritis (OA) causes pain, reduced muscular strength and stiffness of the affected joint. In response, the motor control mechanism is altered, potentially compromising stability during acts of daily living. Reduced walking stability can be quantified in terms of gait variability. This study therefore aimed to identify and quantify the effects of knee arthritis on gait variability. Fifty adults (25 males/25 females) with end-stage OA of the knee sufficiently symptomatic to require joint replacement, walked on a self-paced treadmill for 2min...
January 2018: Gait & Posture
Andrew H Huntley, Alison Schinkel-Ivy, Anthony Aqui, Avril Mansfield
BACKGROUND: The feasibility of using a multiple segment (full-body) kinematic model in clinical gait assessment is difficult when considering obstacles such as time and cost constraints. While simplified gait models have been explored in healthy individuals, no such work to date has been conducted in a stroke population. The aim of this study was to quantify the errors of simplified kinematic models for chronic stroke gait assessment. METHODS: Sixteen individuals with chronic stroke (>6months), outfitted with full body kinematic markers, performed a series of gait trials...
October 2017: Clinical Biomechanics
Rebecca J Reed-Jones, Douglas W Powell
The purpose of this study was to examine the effects of gaze fixation on head stabilization and gait during straight over ground walking in individuals with Parkinson's disease (PD). Eight individuals with PD (Age: 62.3±8.1 years) volunteered for the study. Full body kinematic data were collected at 120Hz using a Vicon motion capture system. Two visual conditions were used to determine the effects of gaze fixation: FREE gaze and FIXED gaze. During FIXED gaze, participants were required to fixate on a still target 13m ahead...
August 10, 2017: Neuroscience Letters
Zlatko Matjačić, Matjaž Zadravec, Andrej Olenšek
In this study we investigated balancing responses to lateral perturbations during slow walking (0.85m/s). A group of seven healthy individuals walked on an instrumented treadmill while being perturbed at the level of waist at left heel strike in outward and inward lateral directions. Centre of mass (COM) and centre of pressure (COP), rotation of pelvis around vertical axis, step lengths, step widths and step times were assessed. The results have shown that beside control of COP in lateral direction, facilitated by adequate step widths, control of COP in sagittal direction, slowing down movement of COM was present after commencement of lateral perturbations...
June 21, 2017: Journal of Biomechanics
Sophia Hulbert, Ann Ashburn, Lisa Roberts, Geert Verheyden
OBJECTIVE: To investigate the effects of ballroom and Latin American dancing classes on turning in people with Parkinson's. DESIGN: This study employed a randomised, controlled, experimental design. SETTING: Dance classes were performed in a community dance centre in Southern England and all assessments took place a gait laboratory. PARTICIPANTS: Twenty-seven people with mild-moderate Parkinson's participated. INTERVENTION: Participants were randomly allocated to receive either 20, 1-h dancing classes over 10 weeks (n=15), or a 'usual care' control group (n=12)...
June 2017: Complementary Therapies in Medicine
Soran Aminiaghdam, Christian Rode
Studies of disturbed human locomotion often focus on the dynamics of the gait when either posture, movement or surface is perturbed. Yet, the interaction effects of variation of trunk posture and ground level on kinetic behaviour of able-bodied gait have not been explored. For 12 participants we investigated the kinetic behaviour, as well as velocity and contact time, across four steps including an unperturbed step on level ground, pre-perturbation, perturbation (10-cm drop) and post-perturbation steps while walking with normal speed with four postures: regular erect, with 30°, 50° and maximal sagittal trunk flexion (70°)...
July 15, 2017: Biology Open
Veronica Cimolin, Nicola Cau, Manuela Galli, Cristina Santovito, Graziano Grugni, Paolo Capodaglio
BACKGROUND: Gait Initiation (GI) is a functional task representing one of the first voluntary destabilizing behaviours observed in the development of a locomotor pattern as the whole body centre of mass transitions from a large to a small base of support. Conversely, Gait Termination (GT) consists in the transition from walking to standing which, in everyday life, is a very common movement. Compared to normal walking, it requires higher control of postural stability. For a safe GT, the forward movement of the body has to be slowed down to achieve a stable upright position...
May 23, 2017: Journal of Neuroengineering and Rehabilitation
Qipeng Song, Xuewen Tian, Del Wong, Cui Zhang, Wei Sun, Peng Cheng, Dewei Mao
The elderly are prone to stair descent falls under low illumination. Tai Chi, a traditional Chinese conditioning exercise, has been proved to improve body stability by altering body condition, gait, and proprioception. This study investigates whether Tai Chi exercise could improve body stability during stair descent under high and low illumination. Three groups of elderly women who practice Tai Chi, brisk walking, and no exercise were included. They descended from a simulated staircase. Tai Chi participants decreased horizontal velocity, centre of mass (COM) sway, and increased foot clearance compared with other participants, these movements could increase body stability; Compared with under high illumination, Tai Chi participants decreased horizontal velocity, loading rate, braking impulse, and increased inclination angle, COM sway, centre of pressure displacement under low illumination...
April 2017: Research in Sports Medicine
Pieter Meyns, Guy Molenaers, Jacques Duysens, Ilse Jonkers
Background: We aimed to study the contribution of upper limb movements to propulsion during walking in typically developing (TD) children (n = 5) and children with hemiplegic and diplegic cerebral palsy (CP; n = 5 and n = 4, respectively). Methods: Using integrated three-dimensional motion capture data and a scaled generic musculoskeletal model that included upper limbs, we generated torque driven simulations of gait in OpenSim. Induced acceleration analyses were then used to determine the contributions of the individual actuators located at the relevant degrees of freedoms of the upper and lower limb joints to the forward acceleration of the COM at each time point of the gait simulation...
2017: Frontiers in Human Neuroscience
François Druelle, Peter Aerts, Kristiaan D'Août, Valérie Moulin, Gilles Berillon
The linear dimensions and inertial characteristics of the body are important in locomotion and they change considerably during the ontogeny of animals, including humans. This longitudinal and ontogenetic study has produced the largest dataset to date of segmental morphometrics in a Catarrhini species, the olive baboon. The objectives of the study were to quantify the changes in body linear and inertial dimensions and to explore their (theoretical) mechanical significance for locomotion. We took full-body measurements of captive individuals at regular intervals...
June 2017: Journal of Anatomy
V Camomilla, T Bonci, A Cappozzo
The position, in a pelvis-embedded anatomical coordinate system, of skin points located over the following anatomical landmarks (AL) was determined while the hip assumed different spatial postures: right and left anterior superior and posterior superior iliac spines, and the sacrum. Postures were selected as occurring during walking and during a flexion-extension and circumduction movement, as used to determine the hip joint centre position (star-arc movement). Five volunteers, characterised by a wide range of body mass indices (22-37), were investigated...
September 6, 2017: Journal of Biomechanics
Cailbhe Doherty, Liang Zhao, John Ryan, Yusuke Komaba, Akihiro Inomata, Brian Caulfield
Gait initiation is a useful surrogate measure of supraspinal motor control mechanisms but has never been evaluated in a cohort following concussion. The aim of this study was to quantify the preparatory postural adjustments (PPAs) of gait initiation (GI) in fifteen concussion patients (4 females, 11 males) in comparison to a group of fifteen age- and sex-matched controls. All participants completed variants of the GI task where their dominant and non-dominant limbs as the 'stepping' and 'support' limbs. Task performance was quantified using the centre of pressure (COP) trajectory of each foot (computed from a force plate) and a surrogate of the centre of mass (COM) trajectory (estimated from an inertial measurement unit placed on the sacrum)...
April 2017: Human Movement Science
Toni Wöhrl, Lars Reinhardt, Reinhard Blickhan
The employment of an alternating tripod gait to traverse uneven terrains is a common characteristic shared among many Hexapoda. Because this could be one specific cause for their ecological success, we examined the alternating tripod gait of the desert ant Cataglyphis fortis together with their ground reaction forces and weight-specific leg impulses for level locomotion and on moderate (±30 deg) and steep (±60 deg) slopes in order to understand mechanical functions of individual legs during inclined locomotion...
May 1, 2017: Journal of Experimental Biology
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