Validation of an inertial measurement unit for the measurement of jump count and height.

Objectives: To validate the use of an inertial measurement unit (IMU) for the collection of total jump count and assess the validity of an IMU for the measurement of jump height against 3-D motion analysis.

Design: Cross sectional validation study.

Setting: 3D motion-capture laboratory and field based settings.

Changes in cortical activity measured with EEG during a high-intensity cycling exercise.

This study investigated the effects of a high-intensity cycling exercise on changes in spectral and temporal aspects of electroencephalography (EEG) measured from 10 experienced cyclists. Cyclists performed a maximum aerobic power test on the first testing day followed by a time-to-exhaustion trial at 85% of their maximum power output on 2 subsequent days that were separated by ∼48 h. EEG was recorded using a 64-channel system at 500 Hz.

Footwear Decreases Gait Asymmetry during Running.

Previous research on elderly people has suggested that footwear may improve neuromuscular control of motion. If footwear does in fact improve neuromuscular control, then such an influence might already be present in young, healthy adults. A feature that is often used to assess neuromuscular control of motion is the level of gait asymmetry.

Ankle muscle strength influence on muscle activation during dynamic and static ankle training modalities.

Muscle weakness is considered a risk factor for ankle injury. Balance training and barefoot running have been used in an attempt to strengthen the muscles crossing the ankle. It is expected that training tasks that successfully strengthen the ankle would elicit increased muscular activity.

Degradation of postural control with aging.

Aging negatively impacts the ability to maintain postural stability due to degraded control systems. The entropic half-life, a non-linear variable that quantifies the transition of sample entropy with increasing time scales, quantifies the time that elapses before old positional information no longer influences, or is no longer related to, the control mechanisms that regulate the movement at the current center of pressure location. The entropic half-life provides a more representative and comprehendible way of detecting changes in complexity using measurement units of time.

The impact of previous knee injury on force plate and field-based measures of balance.

Background: Individuals with post-traumatic osteoarthritis demonstrate increased sway during quiet stance. The prospective association between balance and disease onset is unknown. Improved understanding of balance in the period between joint injury and disease onset could inform secondary prevention strategies to prevent or delay the disease.

Increased vertical impact forces and altered running mechanics with softer midsole shoes.

To date it has been thought that shoe midsole hardness does not affect vertical impact peak forces during running. This conclusion is based partially on results from experimental data using homogeneous samples of participants that found no difference in vertical impact peaks when running in shoes with different midsole properties. However, it is currently unknown how apparent joint stiffness is affected by shoe midsole hardness.

The effects of isolated ankle strengthening and functional balance training on strength, running mechanics, postural control and injury prevention in novice runners: design of a randomized controlled trial.

Background: Risk factors have been proposed for running injuries including (a) reduced muscular strength, (b) excessive joint movements and (c) excessive joint moments in the frontal and transverse planes. To date, many running injury prevention programs have focused on a "top down" approach to strengthen the hip musculature in the attempt to reduce movements and moments at the hip, knee, and/or ankle joints. However, running mechanics did not change when hip muscle strength increased.

Quantification and reliability of center of pressure movement during balance tasks of varying difficulty.

Postural control is often assessed by quantifying the magnitude of the center of pressure (COP) movement. However, these measures usually focus on the gross amount of movement and ignore the temporal structure of the COP signal. A novel non-linear analysis technique was recently developed to characterize the temporal structure of the COP signal with an output termed the entropic half-life [E(1/2)].

Extraction of basic movement from whole-body movement, based on gait variability.

The aim of this study was to quantify the step-to-step variability (SSV) in speed-variant and speed-invariant movement components of the whole-body gait pattern during running. These separate aspects of variability can be used to gain insight into the neuromuscular control strategies that are engaged during running. Ten healthy, physically active, male recreational athletes performed five treadmill running trials at five different speeds (range: 1.

Task-oriented control of muscle coordination during cycling.

Purpose: This study investigated the effects of different biomechanical constraints on the variability of muscle activation during cycling.

Methods: Fifteen male athletes cycled at a power of 150 and 300 W. Surface EMG was recorded from seven lower limb muscles.

Shoe midsole hardness, sex and age effects on lower extremity kinematics during running.

Previous studies investigating the effects of shoe midsole hardness on running kinematics have often used male subjects from within a narrow age range. It is unknown whether shoe midsole hardness has the same kinematic effect on male and female runners as well as runners from different age categories. As sex and age have an effect on running kinematics, it is important to understand if shoe midsole hardness affects the kinematics of these groups in a similar fashion.

Development of a scaffoldless three-dimensional engineered nerve using a nerve-fibroblast co-culture.

Nerve grafts are often required to replace tissue damaged by disease, surgery, or extensive trauma. Limitations such as graft availability, donor site morbidity, and immune rejection have led investigators to develop strategies to engineer nerve tissue. The goal of this study was to fabricate a scaffoldless three-dimensional (3D) nerve construct using a co-culture of fetal nerve cells with a fibroblast monolayer and allow the co-culture to remodel into a 3D construct with an external fibroblast layer and an internal core of interconnected neuronal cells.