Abstract Archive

A framework is proposed to develop an inhomogeneous Finite-Element (FE) model of a human proximal humerus fracture (PHF) with an osteosynthesis device in order to characterize the overall stiffness and load to failure properties under physiological-like loading/test conditions. An experimental set-u...

Instrumented mouthguards are used to record in-vivo head kinematics in sport. The validation of the CSx mouthguard’s capacity to measure linear acceleration was assessed using impact testing versus a reference single-axis accelerometer. The CSx mouthguard’s linear acceleration demonstrated favou...

Hip muscle weakness is a risk factor for many musculoskeletal injuries to the hip and groin region. Instruments used to measure hip muscle strength are designed to assess muscle actions in a single plane, which is not consistent with the multiplanar line of action of many hip muscles. This study aim...

In order to study dynamic balance of stance phase during self-paced walking, variations in orthogonal ground reaction forces (GRF) were examined by using force-plate installed dual belt treadmill. As walking speed increased, standard deviations (SDs) in GRFs tended to be higher both at the beginning...

Falls among the elderly (aged ≥ 65) occur frequently and result in high injury and mortality rates. Studying how older adults regulate stepping to maintain lateral balance is critical to understanding and reducing falling events in this population. Here, we compared how healthy young and older adu...

Old vs young adults had lower ankle plantarflexor but not hip extensor strength. They also showed biomechanical plasticity (BP) through higher hip/ankle ratios of peak joint torques & powers in level & inclined walking. BP ratios were not correlated however with the relative strengths of hip vs ankl...

Deformation and fracture behaviors of five femoral specimens were studied under a stance-type slanted loading orientation, under which the specimens were expected to show relatively low stiffness and large deflection. The proximal femurs were loaded using a specially designed fixture, mounted inside...

In this pilot study, five recreationally trained men performed 5-second isometric contractions in four different deadlifting positions to determine the optimal position for maximal lower-body muscle activation. A graded response was found, with the start position eliciting the greatest muscular acti...

This study examined differences in hip, knee and ankle joint kinematics of a vertical drop jump (VDJ) task between youth with Juvenile Idiopathic Arthritis (JIA) and their age and sex matched typically developing (TD) peers. Youth with JIA performed the VDJ with significantly less knee flexion, redu...

Virtual reality was used to expose healthy younger and older adults to environments anticipated to challenge standing balance. Seven VR environments were compared to baseline standing. Center of pressure range in the anterior-posterior plane (measured by force plate) was significantly increased for ...

Using our lab’s biplane fluoroscopy system, we collected data on eight bone phantoms to assess the accuracy of our custom bead-based and model-based tracking algorithms. Custom rigs were constructed to apply uniaxial rotation and translation to these bone phantoms. External potentiometer measureme...

The purpose of this research was to validate wireless inertial sensor measures of hip joint orientation during dynamic tasks. Inertial sensor derived hip joint angles (found using acceleration, angular velocity, and magnetic field data) are compared to those found using a 3D camera-based laboratory ...

This study compared video-based joint angle and reach envelope measures for simulated working tasks to motion capture and to physical demands description estimates from novice and experienced ergonomists. Video-based measures showed low RMS error and high weighted Cohen’s kappa scores, and demonst...

Analysis of hip contact forces, computed through musculo-skeletal modelling, of 132 total hip replacement patients while performing several activities of daily living.

This paper presents a semi-active ankle prosthesis that adapts its stiffness to accommodate different gym exercises. The prosthesis is pneumatically actuated, and features a wireless adjustment of air pressure via smartphone app as well as a self-replenishing “pumping” mode, allowing operation w...

Deceleration-focused shoulder exercises are becoming integrated into both baseball and softball programs. These exercises address the imbalance between the shoulder internal and external rotator muscles. The effects of a deceleration-focused shoulder exercise program has yet to be examined among the...

With many TARs on the market the variety of implant fixations mechanisms is large. The amount of micromotion within the Bone-Implant-Interface affects clinical success. Current fixations mechanisms are compared to new concepts and a minimization of micromotion within the BII was found.

The energetic cost of muscle force production depends on the contraction type. For example, during mid stance of human walking, the calf muscles show relatively isometric fascicle behaviour, which is thought to be one reason why human walking is highly economical. As fascicle behaviour of the knee e...

Motor control dysfunction in the lumbar spine may alter in the muscle function of deep muscles such as transverse abdominal (TrA) and multifidus (MF). Previous studies have shown that sub-sensory stochastic resonance (SR) stimulation may improves balance and the sensitivity of specific mechanorecept...

Although visual feedback dominates over proprioception during voluntary movements, we do not know how the control of contact forces is affected by either sensory system. We asked subjects to perform a planar reaching task while adapting to a visuomotor rotation which induced a conflict between visio...

Motion capture systems are useful tools for assessing different aspects of human movement. 3D systems are the preferred method as they utilize multiple cameras to gather accurate and reliable measurements. They can be cost-prohibitive and complex to use. In the absence of a 3D system, a 2D system ca...

The purpose of this study was to determine the validity and reliability of a clinic-based treadmill with integrated markerless motion capture. Hip and knee angular measures had moderate to high between-day reliability. However, caution should be exhibited interpreting joint angles from this clinic-b...

The present study examines the validity and reliability of a depth-camera based approach for segment lengths estimation of the pelvis and the lower extremity. For the evaluation, a Kinect sensor and an optical motion capture system were used to automatically deduce the segment lengths of young subje...

Fixed speed treadmills are commonly used in the clinical and research setting but fail to simulate the variation inherent to natural gait that occurs with overground walking (OGW) at a quasi-steady pace for a high number of gait cycles. The self-paced treadmill (SPT) allows for user-driven variation...

Walking speed is one of the important factors in gait analysis. The purpose of the study is to examine the walking speed variation and biomechanical effects caused by the walking speed after wearing the Variable Stiffness Shoes (VSS). Twenty subjects were instructed to walk in three shod conditions,...

Large force variability is a potentially unique signature of spastic muscle that can be estimated using analysis of the force trace during voluntary contractions. Underlying mechanisms of force variation remain largely unknown. However, recently reported findings indicates changes in motor unit disc...

Using a probabilistic modelling framework, we demonstrated that some combinations of varus-valgus component malalignments from the native joint lines during total knee arthroplasty caused elevated tibial forces and ligament tensions during both level walking and stair climbing. Thus, avoiding these ...

OpenSim was primarily developed for gait analysis in which external loads are only applied to the feet. When analyzing cycling in OpenSim, loads from the handlebars and seat are omitted as inputs. This study aims to investigate if OpenSim’s residual reduction algorithm (RRA) is capable of accounti...

This study presents findings from a descriptive video analysis of in-game head impacts in youth football. Parameters detailing each head impact (e.g., frequency, type, mechanism, source, location, etc.) were reviewed and documented for three different age groups (≤ 12 years). A trend towards youth...

To investigate how the foot mobility differs between human and African great apes, we compared three-dimensional bone kinematics of cadaver feet under an axial loading using a biplanar X-ray fluoroscopy system. For the visualization and quantification of detailed foot bony movement, a model-based re...