Abstract Archive

This study investigated EMG activation of the neuromuscular partitions of supraspinatus and infraspinatus during external rotation and abduction tasks against elastic resistance. Twenty-two participants completed dynamic arm movements using Theraband™ elastics while EMG activity from two partition...

Evaluating active translational shoulder stability is essential to quantifying clinically-relevant deficits in individuals with shoulder instability. Estimating impedance with random perturbations allows for this assessment of active translational stability that is not possible with clinical techniq...

We hypothesize that acto-myosin cross-bridge cycling dynamics govern history-dependence in muscle mechanics and muscle spindle afferent feedback that may impact human postural behaviors. Here we combine in vitro, in vivo, and in silico studies to determine movement amplitude thresholds affecting his...

We compared joint kinetics among three footwear types in inexperienced and experienced runners. Minimal footwear increased plantarflexor involvement while highly cushioned footwear increased knee extensor involvement. Experienced runners ran with greater plantarflexor involvement than inexperienced ...

Eccentric exercise training, whereby muscles generate significant tension whilst lengthening, evoke broad ranging adaptations in the musculotendinous system that differ from training where predominately isometric or concentric actions are performed. This provides the opportunity for prioritising ecc...

The prosthesis and the stump must fit together in an optimal way for pressure to be distributed correctly. However, despite these efforts, this contact is not always the most appropriate. The contact between the stump and socket generates high pressure points, causing discomfort and damage to the st...

At short sarcomere lengths (SLs) (1.9 to 2.65 µm) single muscle fibres from old individuals had a greater mean passive modulus than those from young. This resulted in a greater passive stress in the old group at SLs between 2.1 and 3.55 µm. Conversely, at long SLs (i.e. > 3.55 µm) the single fibr...

The prevalence of shoulder pathology increases with age, but the progressive changes driving this pathology remain unknown. Identifying the changes preceding symptom onset may permit early detection and prevention of pathology. Altered strength and coordination are thought to contribute to tissue de...

We tested the effects of age and lateral target distance on reaction time during precision stepping. Compared to young adults, older adults have more missed steps and slower reaction times during reactive lateral stepping in walking. Surprisingly, these apparent deficits, which may relate to an inab...

The Plug in Gait model (PiG) is a commonly used biomechanical model for clinical gait. Recently, an open access alternative model to the PiG has been released for use. In considering the potential to transition to the new model, we are interested in comparing data calculated by the PiG and the new p...

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...

This study determined whether active lower limb muscle volume increased when landing with load and whether it differed between sexes or landing type. Twenty male and seventeen female participants had active hip, knee and ankle muscle volume quantified when performing normal and flexed landings with ...

The purpose of this study was to investigate effect of shoes midsole stiffness on biomechanics of lower extremity joints during Lay-Up (LU) jumping with different stiff midsole shoes. Thirty participants who wore stiff midsole shoes and control shoes performed LU jumps. Kinematics and ground reactio...

The intrinsic foot muscles are known to contribute to postural control during upright stance and locomotion. However we know little about the role of these muscles in stabilization following unexpected perturbations. We conducted an experiment in which subjects were trained to repeatedly step at a p...

Competitive rowing highly values boat position and velocity data for real-time feedback during training, racing and post-training analysis. The ubiquity of smartphones with embedded position (GPS) and motion (accelerometer) sensors motivates their possible use in these tasks. In this work, we presen...

Gait parameters (locomotion bout, speed, cadence, variability) obtained during long-term recording through wearable sensors are presented for a large cohort to highlight the importance of real-world (RW) gait analysis. A new framework for optimizing gait algorithms in RW situations for each individu...

This research examined age-related changes in muscle strength and multi-channel surface electromyography (EMG) spatial parameters during isometric and isokinetic knee extensions. Peak torque, mean EMG amplitude, intensity, entropy and Coefficient of Variation (CV) were compared across age and sex. W...

The purpose of this study was to compare the changes in gait spatio-temporal variables during metronome walking in healthy young adults and elderly groups. In the metronomic walking, the mean and variability of stride time were decreased in young adults group, but the mean of stride length and strid...

We used a new experimental approach in a rabbit model to test for differences in the rate of force development among the individual quadriceps muscles and to assess their contribution to total torque during force development. We highlight that simultaneous and identical activation does not result in...

These data provide an understanding in skeletal muscle of the relative roles of various ECM proteins in providing passive muscle stiffness and show that the normal balance amongst extracellular matrix components of muscle is lost in cerebral palsy. In addition, these data may provide insights into t...

Following active muscle lengthening there is less activation (i.e., Electromyography; EMG) required to match a given torque target as compared with a purely isometric contraction. This activation reduction (AR) is typically investigated during torque matching tasks. It is less clear whether followin...

We examined the discriminant ability of features extracted from walking and running contact force data using instrumented insoles in order to optimize future classification model accuracy. Twenty-seven subjects walked and ran on four treadmills with varying deck stiffness at both self-selected and c...

Deficits in quadriceps strength are common following anterior cruciate ligament reconstruction (ACL-R) and can influence alterations in gait mechanics. Functional resistance training (FRT) may improve gait mechanics, yet, the best approach to implement FRT is not clear. Here, we report the acute eff...

The purpose of this study was to determine if coordination variability between the trunk and pelvis during walking turns is reduced in response to fatiguing muscle exercise. The secondary purpose was to compare two statistical methods of quantifying variability; Vector Coding and the Ellipse Area Me...

Research and design of ankle-foot prostheses has largely focused on optimizing ankle function; however, the potential benefits of modifying the foot keel remain relatively unexplored. In particular, the addition of a toe joint has the potential to positively impact the gait biomechanics of prostheti...

Fall-related traumatic brain injuries (TBI) are a major health concern in older adults. However, there is little information known about the age-related differences in head impacts during a fall. The current investigation found that physically fit older adults had a greater proportion of head impact...

The purpose of this study was to investigate the associations between range of motion (ROM) and stiffness of muscle, fascia and nerve in young and elderly individuals. Ankle dorsiflexion ROM was determined based on onset of pain using a dynamometer. Tissue stiffness was evaluated by ultrasound shear...

Natural adult aging is associated with a reduction in muscle force production capacity during isometric and shortening contractions. However, during active lengthening of muscle, force is well-maintained into old age. In this symposium I will discuss the age-related maintenance of eccentric strength...

There is limited information on the effect of foot strike angle (FSA) on the resultant ground reaction force vector angle (θR-GRF) and the leg vector angle (θL). Human participants ran on a treadmill with a forefoot strike (FF) and a rearfoot strike (RF) according to biofeedback criteria of their ...

Individuals with lower extremity bone tumors (osteosarcoma or Ewing’s sarcoma) have complex reconstructive procedures which may result in changes to muscle architecture. This preliminary work demonstrates the use of static and extended field-of-view ultrasound to measure architecture of the vastus...