Abstract Archive

The goal of this study was to understand the mechanism of falls in the elderly using the complexity analysis of center of pressure (CoP) in those who fall and those who do not fall. Approximate Entropy (ApEn) was calculated to determine the levels of complexity of CoP during walking on an instrument...

A majority of physical activities which experience impacts during ground contact generate soft tissue vibrations. Those vibrations could potentially cause injury and energy lost due to high muscle tone associated with the vibration. Study has been reported the energy used by the muscles when exposed...

The concurrent validity and reliability of two mobile applications designed to measure vertical jump heights were analyzed in this study using a force platform and 3D motion analysis as criterion methods. The results showed that jump height can be accurately and reliably estimated using these mobile...

Musculoskeletal simulation models are popular to investigate injury situations on a computer. The existing musculoskeletal simulation models typically consist of a rigid multi-body model and muscles. Rigid segments prevent some mechanical behaviour of bones from being considered. In this study a com...

This study employed a novel, micro-grooved finite element model to characterize the contact mechanics at the total hip head-neck modular taper junction during implant assembly under different conical angles and head taper surface topography. Modeling the head taper as an idealized “flat” surface...

To estimate the contribution of individual muscles to steadily control measurable net force during isometric contractions in a multiple-muscle model, we calculated cross correlation function between isometric plantarflexion force and rectified surface EMG (rEMG) of the involved muscles in low freque...

Anatomical evidence points to the existence of 6-8 architecturally distinct partitions within the pectoralis major (PM), suggesting differential contributions of these partitions to humeral movement. This study investigated the activation of PM partitions using high-density electromyography in three...

Frontal-plane ankle motion is important for balance in walking, but is seldom controlled in robotic prostheses. This abstract describes the control and performance of a semi-active two degree of freedom robotic prosthetic ankle. The mechanism uses a nonbackdrivable cam wedge system based on rotating...

The force-length relationship in skeletal muscle is attributed to the requirement for overlap between the contractile proteins actin and myosin. However, this relationship shifts with changes in muscle activation. Here we present data suggesting that this activation-dependent shift occurs not only b...

Cells are constantly exposed to loads, which are sensed by their organelle and transduced into cellular events, a phenomenon called mechanotransduction. Despite receiving significant attention over the past years and exponential advances in cell characterization techniques, understanding how mechani...

This study tested the concurrent validity of pose estimation from markerless motion capture against those collected using a marker-based technique. Kinematic data were recorded simultaneously while ten male participants walked over ground at their self-selected speed. Sagittal plane joint angles dem...

We investigated role of biomechanical and neural constraints in the formation of the plantar covariation of hindlimb elevation angles during walking in the cat. Using experimental and computational methods we found evidence that neural spinal circuitry may be responsible for the planar covariation.

The aim of this study was to investigate and evaluate the role of mechanical and neural modulations after stretch-shortening cycles (SSCs). Net ankle joint torque and H-reflexes of triceps surae were obtained during different tetanic contraction conditions, elicited by tibial nerve stimulation. Whil...

The present study has revealed that the kinetic chain of rearfoot pronation-supination and shank rotation contributes to lateral motion control of the knee during early stance. The subjects were 26 healthy adults. The kinematic chain ratio (conversion rate of shank rotation angle in relation to rear...

This study compared lower limb loading characteristics between individuals post-stroke and age-matched controls. Findings suggest that reduced joint angular displacement and delayed center of pressure control during limb loading may be important factors that contribute to functional deficits in weig...

Partial power assistance is a promising approach to reduce the deleterious upper extremity loads in manual wheelchair locomotion. This study investigates two potential control strategies to govern the wheelchair-user interaction: i) an impedance control strategy, where a reference, desired system dy...

Children with Autism Spectrum Disorder (ASD) exhibit different movement patterns relative to their peers with typical development (TD). Few distinguishable patterns have been determined, although some have been hypothesized. The current study analysed whether coordination variability (vCRP) of the l...

Knee joints undergo various loading and unloading processes. Earlier investigations had a marginal focus on rate-dependent load response associated with viscoelastic and poromechanical behaviors of the joint. In this study, a fully meniscectomized porcine knee joint compression was simulated with a ...

Jump landing manoeuvres in competitive downhill skiing are typical situations leading to ACL injuries. While, neuromuscular control is considered a key injury risk factor, optimum control strategies are unknown. The purpose of the study was to compute muscle activation patterns that minimize ACL for...

Imaging-based approaches for quantifying joint kinematics and arthrokinematics of joint movement have become more commonplace in the research environment. Both static and dynamic approaches are being utilized to quantify rotation and translation of the shoulder joint complex in global and anatomical...

This simulation study examined the effect of the constrained center of mass (COM) trajectory on spatiotemporal organization of the via-angles, i.e., the via-posture of a kinematic chain, in order to explore the determinant of the joint coordination. A minimum-jerk criterion with via-point constraint...

Dr. Wong applies computational models and human experiments to questions across the realms of sensorimotor control, from reaching to energy optimization in locomotion. Here he will discuss his recent work towards understanding how the nervous system senses energy use by investigating the role of blo...

The incidence of knee injuries in sport are well documented with several key variables associated with the risk of injury during cutting and landing identified. The contribution of lower extremity muscle activity is lesser known but may provide insights into the mechanisms as well as training and pr...

Basketball shots are taken from a variety of horizontal and vertical positions relative to the basketball hoop with and without momentum. Here, we hypothesized that the greater the velocity of the total body, the less the arms need to contribute to the vertical velocity of the ball at release. The r...

Humans are adept at running on rough terrains without falling. Previous modeling work hypothesizes that minimizing tangential collisions is critical for stability. By analyzing thousands of steps from overground rough terrain experiments of human runners, we show that the main mechanism to eliminate...

Constraining step length and speed in humans can result in pronounced changes in gait, but such situations seldom occur naturally. In contrast, many quadrupeds have pairs of legs with differing lengths. Since these pairs translate at the same absolute speed and stride lengths, they present a natural...

The relationship between coordination variability and running related overuse injuries has not been examined prospectively. Understanding this relationship will aid in identifying the loading effects of joint coordination on mechanically crucial musculoskeletal sites. Vector coding was used to deter...