Paul Allard

• Doctor of Philosophy
• Université de Montréal

Left–right differential erector spinae (ES) muscle strengthening is required to correct ES muscle imbalances. The objective was to test the effect of 6 body positions on the differential activation of the ES muscles. In 14 able-bodied young women, using a surface electromyography system, the bilateral ES muscles activity at the third lumbar (ES L3...

The purpose of this investigation was to determine the effect of unexpected gait termination in able-bodied participants during gait initiation on spatiotemporal and stance limb biomechanical parameters. Twenty-one healthy adults took part in this study and were divided into two groups based on the natural anterior or posterior incline of their tru...

Introduction Lower limb amputation impairs postural performance that could be characterized by biomechanical parameters. This study is to investigate postural performance of persons with transfemoral and transtibial amputation compared to controls without amputation. Methods Eight transtibial, nine transfemoral and twelve able-bodied males partici...

Introduction This study investigated self-paced voluntary oscillations of scoliotic and non-scoliotic girls. Temporal variables and frequency coherence were calculated for the overall, low and high frequency bandwidths of the center of pressure excursions and free-moment to identify which variables best describe sway balance modalities in both grou...

Background: This study test if the frequency coherence calculated for the overall, low and high frequency bandwidths of the center of pressure excursions and free-moment calculated during standing balance are similar between scoliotic and non-scoliotic girls and if the coherence values within each frequency band are comparable for a given group of...

Ensuring glenohumeral stability during repetitive lifting tasks is a key factor to reduce the risk of shoulder injuries. Nevertheless, the literature reveals some lack concerning the assessment of the muscles that ensure glenohumeral stability during specific lifting tasks. Therefore, the purpose of this study was to assess the stabilization functi...

Average (±1 standard deviation represented by the shaded envelop) joints torques obtained with inverse dynamics (red), and residuals torques obtained with static optimization (blue) for the 13 degrees of freedom actuated by the muscles model. Time is normalized with respect to trial duration. (DOCX)

Individual data used to perform the statistics. (XLSX)

Average (±1 standard deviation represented by the shaded envelop) muscle model activations obtained with static optimization (in red) and normalized EMG (in blue). Time is normalized with respect to trial duration. (DOCX)

Background: Generally, scoliotic girls have a tendency to lean further back than a comparable group of non-scoliotic girls. To date, no study has addressed how standing balance in untreated scoliotic girls is affected by a natural backwardly or forwardly inclined trunk. Methods: 27 able-bodied young girls and 27 young girls with a right thoracic...

Impaired gait patterns are often compared to that of a group of able-bodied subjects. This latter group usually forms a gold standard. Variability in able-bodied gait parameters could reflect different normal locomotion patterns. Furthermore, a lack of statistical difference between patient data and control subjects can hide a perturbed gait patter...

Introduction La terminaison de la marche, planifiee (Roeing et al., 2015) ou non (Jung et al., 2016), peut etre utilisee afin de perturber la stabilite posturale d’une personne. L’objectif de cette etude est de presenter une methode pour evaluer l’impact d’un arret soudain lors de l’initiation de la marche sur les moments articulaires generes au ni...

Background: Some patients with rotator cuff tears feel pain without functional limitation, whereas others show a decrease in range of motion. To investigate this distinction, the scapulohumeral rhythm was used to conduct a functional evaluation of shoulder joints' coordination. The objective was to characterize patients according to their active r...

Context: Supraspinatus tear is a common rotator cuff injury. During rehabilitation, debate persists regarding the most appropriate exercises. Whereas shoulder coordination is part of normal arm function, it has been infrequently considered in the context of exercise selection. Objective: To assess shoulder-motion coordination during 2 common sup...

While sagittal trunk inclinations alter upper body biomechanics, little is known about the extent of frontal trunk bending on upper body and pelvis kinematics in adults during gait and its relation to sagittal trunk inclinations. The objective was to determine the effect of the mean lateral trunk attitude on upper body and pelvis three-dimensional...

The purposes of this study were to estimate head and trunk's (HT) radii of gyration (K) and moments of inertia (I) in able-bodied and unbraced scoliotic girls using an angular momentum method, to test if the use of mean ratios calculated in this study and given by de Leva present similar values compared to the experimental data, and to determine ho...

Few musculoskeletal models are available to assess shoulder deeper muscle demand during overhead lifting tasks. Our objective was to implement a musculoskeletal model to assess the effect of lifting height and load on shoulder muscle work. A musculoskeletal model scaled from 15 male subjects was used to calculate shoulder muscle work during six lif...

Scoliosis is a three-dimensional (3D) deformation of the spine and the pelvis. While the relation between the pelvic asymmetries and scoliosis progression was proposed by several authors, it has not been documented over time in adolescent idiopathic scoliosis (AIS). The objective was to determine whether vertebral wedging and pelvic asymmetries pro...

Cinématique et modélisation biomécanique de l'épaule lors de tâches de manutention Prévention durable en SST et environnement de travail

It has been shown that an original attitude in forward or backward inclination of the trunk is maintained at gait initiation and during locomotion, and that this affects lower limb loading patterns. However, no studies have shown the extent to which shoulder, thorax and pelvis three-dimensional kinematics are modified during gait due to this sagitt...

Vertebral wedging is associated with spinal deformity progression in adolescent idiopathic scoliosis. Reporting frontal and sagittal wedging separately could be misleading since these are projected values of a single three-dimensional deformation of the vertebral body. The objectives of this study were to determine if three-dimensional vertebral bo...

https://isbweb.org/images/stories/conferences/isb-congresses/2013/poster/ps2-16e.pdf

https://isbweb.org/images/stories/conferences/isb-congresses/2013/oral/cb-shoulder1.08.pdf

The purpose of this study was to determine how pelvic morphology, body posture, and standing balance variables of scoliotic girls differ from those of able-bodied girls, and to classify neuro-biomechanical variables in terms of a lower number of unobserved variables. Twenty-eight scoliotic and twenty-five non-scoliotic able-bodied girls participate...

Anthropometric tables are not applicable to calculate the scoliotic trunk mass and center of mass (COM). The purposes of this study were: (1) to estimate the head and trunk mass and COM in able-bodied and scoliotic girls using a force plate method, (2) to estimate head and trunk COM offset compared to those of the body, and (3) the use of mean rati...

Background: There is a high incidence of retear following surgical repair of rotator cuff tears. Postoperative shoulder immobilization is commonly prescribed to protect the repair; but there is no consensus on the best immobilization postures. Methods: A generic musculoskeletal model of the shoulder was used to simulate postoperative immobilizat...

Adolescent idiopathic scoliosis (AIS) is the most common form of scoliosis and usually affects young girls. Studies mostly describe the differences between scoliotic and non-scoliotic girls and focus primarily on a single set of parameters derived from spinal and pelvis morphology, posture or standing imbalance. No study addressed all these three b...

To identify pelvic rotation and/or distortion in able-bodied and untreated AIS girls with moderate and severe scoliosis and verify association of pelvic morphological changes with Cobb angle increase. The 3D coordinates of nine anatomic bony landmarks were identified to estimate pelvic orientation using a Flock of Birds system. The distances betwee...

https://isbweb.org/images/conf/2011/ScientificProgram/ISB2011_ScientificProgram_files/601.pdf

Le présent ouvrage s'adresse aux étudiants en sciences et techniques de l'activité physique et sportive, en kinésiologie et autres disciplines connexes. Cette troisième édition s'inscrit dans l'esprit d'amélioration des connaissances de la pratique en biomécanique. De nouveaux collaborateurs se sont joints à l'équipe de rédaction et huit nouveaux c...

In adolescent idiopathic scoliotic girls, postural imbalance is attributed to a sensory rearrangement of the motor system on the representation of the body in space. The objectives of this study were to test if the anteroposterior (AP), mediolateral (ML) and resultant body-head and trunk center of mass (COM) horizontal offsets were similar in able-...

Classical models to estimate the head and trunk (HT) moments of inertia (I) are limited to populations from which the anthropometric measures were obtained. The purposes of this study were to determine if the angular momentum technique can be used to estimate subject-specific HT's I values and test its validity and sensitivity. Twenty-three adults...

The purposes of this study are to assess the relationship of the center of pressure (CoP) displacement parameters along the mediolateral and anteroposterior axes to whole-body oscillations about the vertical axis during single or double leg upright stance and to determine whether sensory deprivation and stance modify balance stability about the ver...

The aim of this study was to test the hypothesis that imbalance in patients with a severe deformity of the spine is associated with an increase in the sensory integration disorder. This paper is a case comparison study. Patients were divided into three groups: able-bodied (n = 53), observation (n = 23), and pre-brace (n = 26) groups. Time domain pa...

Body segment masses and center of mass (COM) locations are required to calculate intersegmental forces and net joint moments using inverse or forward dynamics equations. These inertial properties are estimated from methods involving cadavers or living individuals. The present clinical methods are limited to similar populations from which the anthro...

Body segment moments of inertia (MOI) are estimated from data obtained from cadavers or living individuals. Though these methods can be valid for the general population, they usually are limited when applied to special populations (e.g., obese). The effect of two geometric methods, photogrammetry and two new methods, namely, inverse dynamics and an...

Changes in foot orientation due to orthoses and the relationship with perceived comfort are still unclear in pes cavus. The purpose of this study was to determine the acute changes of fore-foot angles due to the use of custom-made orthoses and their relationship with perceived comfort during standing. Two photographs were taken using a color-coded...

Adolescent idiopathic scoliosis (AIS) is characterized by morphological trunk modifications acting on body mass distribution. Some specific biomechanical strategies during postural regulation have been reported. Given that spinal deformity is three-dimensional, some strategy analysis resulting from different stepping directions should lead to a bet...

Le corps humain est une merveilleuse machine qui permet à chacun d'entre nous de mener une multitude d'activités utilitaires, de loisirs ou encore sportives. Pourtant, cette machine subit des contraintes mécaniques qu'il convient de connaître afin d'en limiter les conséquences. Elle ne fonctionne pas uniquement dans un cliquetis de rouages ou de pi...

Though the effect of imposed trunk posture affects walking patterns little is known about the effect of natural orientation of the trunk on gait. The objectives of this study are to test if the lower limb joint and thoraco-lumbar moments are similar in subjects who maintain an average natural forward or backward trunk inclination during gait and ve...

Changes in magnitude and timing of rearfoot eversion and tibial internal rotation by foot orthoses and their contributions to vertical ground reaction force and knee joint moments are not well understood. The objectives of this study were to test if orthoses modify the magnitude and time to peak rearfoot eversion, tibial internal rotation, active g...

The idiopathic scoliosis is characterized by a three-dimensional spinal deformity involving new dynamical strategies to regulate the posture. The aim is to analyze the centre of pressure (CP) behaviour in forward stepping (FS) and lateral stepping (LS) to determine the dynamical consequences of scoliosis. Ten adolescents suffering from right thorac...

Unlabelled: There is a need for a user-friendly system that can provide quick and reliable assessment of foot disorders. The study described in this report was undertaken to determine the inter-rater and intra-rater reliability of a computer-aided, color-coded, video-based system developed for the assessment of foot alignment in patients with and...

Since trunk morphology and curve types were reported to affect standing in adolescent idiopathic scoliosis (AIS), it is reasonable to assume that bracing could perturb standing balance in this population. The objective here was to use time- and frequency-domain analyses to test if the Boston brace affects balance in AIS. Fifteen AIS girls were fitt...

Adolescent idiopathic scoliosis (characterized by a morphological deformation of the trunk) prompts the development of new postural control strategies. This adaptation has an influence on the dynamics of motor behaviour. The present study analysed ground reaction forces during lateral stepping in order to highlight the dynamic consequences of idiop...

Adolescent idiopathic scoliosis girls are known to display standing imbalance. In addition to a motor deficit problem, the axial torsion of the spine and trunk torsion could reflect an imbalance around the vertical axis. Unlike the excursion of the center of pressure (COP), the forces and moments were rarely addressed to characterize the quiet stan...

INTRODUCTION. La scoliose idiopathique de l’adolescent (SIA) est une déformation tridimensionnelle du rachis qui a pour conséquence de modifier la géométrie du tronc. Une telle déformation génère des modifications inertielles des segments qui sont intégrées via le développement de stratégies spécifiques pour conserver l’équilibre. La caractérisatio...

Based on twisted plate and mitered hinge models of the foot and ankle, forefoot-rearfoot coupling motion patterns can contribute to the amount of tibial rotation. The present study determined the differences of forefoot-rearfoot coupling patterns as well as excessive excursion of tibial internal rotation in shod versus barefoot conditions during ru...

Background: Wedge posted foot orthotics could prevent abnormal compensatory motions in the proximal joints by aligning the subtalar joint and ankle. However, the effect of wedge positions on the compensations of the subtalar joint and its proximal joints and segments in maintaining posture are not well understood. Objective: To test the effect of f...

Using statistical characteristics of the centre of pressure displacement or of the ground reaction forces, it is difficult to have quantitative evaluation of the equilibrium strategy employed (ankle or hip). The purpose of this study is to validate a new force-plate based approach that allows to evaluate postural strategies employed through a metho...

Balance control is influenced by the availability and integrity of sensory inputs as well as the ability of the balance control mechanisms to tailor the corrective action to the gravitational torque. In this study, to challenge balance control, visual and ankle proprioceptive information were perturbed (eyes closed and/or tendon vibration). We mask...

Scoliosis is the most common type of spinal deformity. In North American children, adolescent idiopathic scoliosis (AIS) makes up about 90% of all cases of scoliosis. While its prevalence is about 2% to 3% in children aged between 10 to 16 years, girls are more at risk than boys for severe progression with a ratio of 3.6 to 1. The aim of the presen...

This study analysed the relationships among arm coordination symmetry, motor laterality and breathing laterality during a 100-m front crawl, as a function of expertise. Ten elite swimmers (G1), 10 mid-level swimmers (G2), and 8 non-expert swimmers (G3) composed three skill groups, which were distinguished by velocity, stroke rate, stroke length, br...

The study of body composition and shape goes back to the 5th century BC. But it was only in the last century that Sheldon (1940)6 structured it into a method for the description of human body morphology, expanding on simple anthropometric measurements. This qualitative method became quantitative and objective by Carter and Heath (1990).14 Somatotyp...

The objective of this study was to determine the effect of body somatotype on standing balance in girls with adolescent idiopathic scoliosis (AIS) who are under observation but not wearing a body brace. In all, 74 girls participated in this study to form the able-bodied (n = 36) and the AIS (n = 38) groups, having an average age of 13 yrs. Quiet st...

Background: Though the effect of imposed trunk posture affects walking patterns little is known about the effect of natural orientation of the trunk on gait. The objectives of this study are to test if the lower limb joint and thoraco-lumbar moments are similar in subjects who maintain an average natural forward or backward trunk inclination during...

To assess the effects of idiopathic scoliosis on undisturbed postural control in young female teenagers. The centre of pressure (CP) displacements, measured through a force platform, were decomposed into two elementary components in order to differentiate the net postural performance, as revealed by the horizontal motions of the centre of gravity (...

Purpose of the studyTo assess the effects of idiopathic scoliosis on undisturbed postural control in young female teenagers.Material and methodsThe centre of pressure (CP) displacements, measured through a force platform, were decomposed into two elementary components in order to differentiate the net postural performance, as revealed by the horizo...

Purpose of the studyTo assess the effects of idiopathic scoliosis on undisturbed postural control in young female teenagers.

Biomechanical models are used with force-plate information to determine the center of mass (COM) trajectory during standing. They are usually based on simplifying assumptions and are often limited to a single-plane analysis. The objectives of this study were to present a three-dimensional (3-D) model to calculate the excursion of the COM of the hum...

The objectives of this study were to demonstrate that data from a video-based system could be used to estimate the net effect of the external forces during gait, to determine the contribution of the trunk and upper and lower limbs using their accelerated body masses, and to test the hypothesis that the thigh mainly assumed lower limb propulsion dur...

The Standardization and TerminologyCommittee (STC) of the International Societyof Biomechanics (ISB) proposes a general reporting standard for joint kinematics based on the Joint Coordinate System (JCS), first proposed by Grood and Suntay for the knee joint in 1983 (J. Biomech. Eng. 105 (1983) 136). There is currentlya lack of standard for reportin...

A retrospective study of standing imbalance and body posture in 71 able-bodied girls and subjects with adolescent idiopathic scoliosis was conducted. To test the hypothesis that postural parameters are related to standing stability parameters. Spinal deformity not only modifies the shape of the trunk, but also changes the relations between body seg...

This study was undertaken to demonstrate that the ankle frontal muscle power absorption and generation at push-off are related to the foot's initial position at heel-strike with respect to the body center of mass. Nineteen able-bodied male subjects participated in this study and were divided into two groups according to ankle frontal plane power ge...

The Standardization and Terminology Committee (STC) of the International Society of Biomechanics (ISB) proposes a general reporting standard for joint kinematics based on the Joint Coordinate System (JCS), first proposed by Grood and Suntay for the knee joint in 1983 (J. Biomech. Eng. 105 (1983) 136). There is currently a lack of standard for repor...

The Standardization and Terminology Committee (STC) of the International Society of Biomechanics (ISB) proposes a general reporting standard for joint kinematics based on the Joint Coordinate System (JCS), first proposed by Grood and Suntay for the knee joint in 1983 (J. Biomech. Eng. 105 (1983) 136). There is currently a lack of standard for repor...

This study was undertaken to demonstrate how principal component analysis (PCA) can be used to detect the main functional structure of actions taken by knee flexors/extensors during able-bodied gait. PCA was applied as a classification and curve structure detection method for knee sagittal muscle moment developed during walking of 20 young, healthy...

To determine if compensatory actions take place at the pelvis and other joints of the affected lower limb in subjects who were in an early stage of hip osteoarthritis (OA). Nonrandomized, case-control study. A gait laboratory. Seventeen patients with OA of the hip (clinical group) matched with 17 healthy elderly subjects (nonclinical group). Video...

Study Design. A retrospective study of standing imbalance and body posture in 71 able-bodied girls and subjects with adolescent idiopathic scoliosis was conducted. Objective. To test the hypothesis that postural parameters are related to standing stability parameters. Summary of Background Data. Spinal deformity not only modifies the shape of the t...