Abstract Archive

Arthrogenic muscle inhibition (AMI) after ACL reconstruction is a result from neural inhibition and quadriceps muscle atrophy. Asymmetrical quadriceps muscle strength has also been reported after ACLR and is associated with altered biomechanics during dynamic movement tasks. It is currently unknown ...

Spatio-temporal evolution of joint space width (JSW) during motion is of great importance to help with early treatment plans for degenerative joint diseases like osteoarthritis (OA). However, only a few studies have attempted to quantify the JSW from moving joints and the accuracy of measurements al...

Mechanical loading of the spine has shown to be an important risk factor for the development of low-back pain. A passive flexible beam exoskeleton was tested during static bending tasks and during lifting. The EXO reduced back muscle activity by 20-40% (i.e. 2-4% MVC) during static bending and aroun...

A multiscale model of the lumbar spine was developed to characterize the link between whole-body and tissue-level biomechanics for people with and without a transtibial amputation during sit-to-stand. Lumbar spine kinematics predicted trends in tissue loads well for annulus fibrosis stress vs. flexi...

The results obtained using the conventional method of measuring the center of pressure (COP) trajectory during gait are influenced by the foot progression angle. To correct this, a method was developed and differences in measurements between the new and conventional methods were identified. The subj...

Cartilage defects have been suggested to cause abnormal loading of subchondral bone, which may cause an adaptive response in the bone. Here, we developed an adaptation algorithm for subchondral bone based on maximum shear strain. Strains above the physiological level were assumed to cause an increas...

Reports that medial knee osteoarthritis (OA) is associated with the peak knee adduction moment during walking (pKAM) have led to interventions to reduce pKAM. However, these interventions require repeated costly gait tests to monitor pKAM changes. Thus, the objective of this study was to develop a s...

Upright human standing requires stabilization of both translational and rotational degrees-of-freedom in the sagittal plane that is primarily accomplished by coordination of joint torques at the hip, knee, and ankle. Those torques produce the ground-on-foot force (F) which has recently been shown to...

We compared movement accuracy and smoothness during goal-directed reaching movements in myoelectric prosthesis users and able-bodied controls. We measured movement accuracy as the distance error in matching a virtual target and quantified trajectory smoothness as the spectral arc-length (SPARC). Mov...

Current measures of growth plate shape are limited to 2D. However, bone growth is a 3D process and methods for measuring 3D growth plate changes are critical for understanding direction of bone growth. This research presents a method for quantifying 3D growth plate shape to assess differences betwee...

We present a novel multiscale modelling approach for investigating knee joint tissue mechanics during dynamic activities. Based on a musculoskeletal model with 12 degrees of freedom (DOF) knee joint (tibiofemoral and patellofemoral joints), muscle forces, knee joint contact forces and moments, and t...

The purpose of this study was to compare elderly faller classifications using pressure mat and force parameters as input to machine learning algorithms. Balance and gait were assessed using pressure mat and force plate data in 59 non-fallers (NF) and 41 fallers (F). Biomechanical parameters included...

The purpose of this research was to clarify a mechanism of body orientation change at the approach phase to curved path in the sprinting event such as 200m or 400m. As a result, the authors revealed that the direction of the runner’s velocity already changed before the curvature. Then, once runner...

A system to generate mechanical load to the musculoskeletal system, through neuromuscular electrical stimulation (NMES), was developed, with load control through an isometric dynamometer adapted for bed-rest situations. The system allows for the control of several NMES parameters, and positions the ...

Traditional static optimization, which minimizes muscle activations squared, may not accurately estimate muscle activity in pathological populations that have abnormal muscle co-activation. A Matlab-OpenSim interface was created to develop and test objective functions that included a muscle co-activ...

Quadriceps weakness is a common clinical sign following anterior cruciate ligament reconstruction surgery (ACLR). We examined quadriceps strength and limb symmetry index (LSI) from different types of functional tests: isokinetic dynamometry, hop tests, and leg press. A total of 26 subjects with ACLR...

The mechanical impedance of active muscle affects the stability of musculoskeletal systems to perturbations. Following a recent experimental finding, we have developed a three filament muscle model in which myosin loads titin when shortening and clutches onto titin during lengthening. A virtual acti...

The foot medial-longitudinal arch (MLA) is perhaps the most important feature characterizing foot morphology. Current MLA models based on skin-markers for motion analysis allow non-invasive assessment of foot arch shape and deformation, but little is known on their anatomical accuracy and repeatabil...

Rehabilitation following anterior cruciate ligament (ACL) injury may be facilitated by a greater understanding of ACL force during activities used to prepare athletes for return to sport. Peak ACL tension and ACL impulse were compared among 40 recreational athletes during 8 rehabilitation activities...

Pathomechanics of diabetic foot ulceration has been largely investigated by plantar loading measurements, and recently also by human motion analyses [1]. Rarely medical imaging has been used, because this is static, and also radiograms are in 2D, and standard CT scans are performed in supine, i.e. i...

Wearable instruments for gait analysis offer new opportunities to study human motion during activities of daily living (ADL). Previous work has overlooked the importance of characterizing non-steady state ADL such as sit-to-stand, gait initiation/termination and turning using wearables. The purpose ...

This study aims to compare the regional load transfer forces of consecutive steps between typically developed children and children with congenital talipes equinovarus (CTEV or clubfoot).

We introduce a multiscale muscle spindle model that provides a framework to simulate the effects of altered muscle properties, neural dynamics, and descending drive on muscle spindle sensory feedback. Our recent work shows that muscle spindle stretch responses in relaxed muscle have a unique relatio...

Cervical spine injuries are one of the most common diagnosed pathologies in traffic car accidents. Diagnosis is given according to patient’s symptoms and visual inspection. However, it is unknown if the diagnosis reflects also the functional impairment of the patient. The ROM data acquired with th...

Hamstring strain injuries (HSIs) are the most common and recurrent soft tissue injury in Australian Rules Football (ARF) [1], with only minor reductions in prevalence observed over the past 20 years. While common belief suggests that hamstring injuries are most likely to occur during terminal swing ...

The use of platelet-rich plasma (PRP) injections in the treatment of acute Achilles tendon rupture (ATR) remains controversial. This double-blinded, randomized controlled trial aimed to compare the effectiveness of PRP versus placebo injections in non-operatively treated ATR patients. Estimates of t...

We developed a single body-mounted sensor that integrates a 3-axis accelerometer, 3-axis gyroscope, 3-axis magnetometer, barometer, and GPS. The sensor accurately computes speed, acceleration, location, angular velocity and angular orientation at 400 Hz. Steps are also segmented and metrics computed...

This study examines the discrepancy between an assumed neutral-zero position and the actual posture of the lower extremity of young and elderly subjects during the calibration process of an IMU system. The joint angles were calculated using a marker based optical motion capture system. The results s...

Activities of daily living (ADL) require rotator cuff muscles. Architecturally and neuroanatomically distinct partitions within these muscles demonstrate differential activation in moderate-to-high demand tasks. However, partition activation during ADLs is unknown. This study investigated supraspina...