STUDY DESIGN Single-subject with repeated measures. OBJECTIVES To determine if runners can use real-time visual feedback from an accelerometer to achieve immediate reductions in tibial acceleration and vertical-force loading rates. BACKGROUND Stress fractures are a common injury among runners. Previous studies suggest that runners with higher than normal tibial acceleration and vertical-for...

The swimming involves accelerations and decelerations in the swimmer's body. Thus, the main objective of this study is to make a temporal and frequency analysis of the acceleration in front crawl swimming, regarding the gender and the performance. The sample was composed by 31 male swimmers (15 of high-level and 16 of low-level) and 20 female swimmers (11 of high-level and 9 of low-level). The ...

OBJECTIVE The objective of the study was to determine which vehicle factors are significantly related to pelvic injury in side impact collisions. Identification of relevant parameters could aid in the reduction of these injuries. METHOD Side impact crashes from the CIREN database were separated into those in which the occupant sustained a pelvic fracture and those in which no pelvic fracture ...

Simple methods to quantify ground reaction forces (GRFs) outside a laboratory setting are needed to understand daily loading sustained by the body. Here, we present methods to estimate peak vertical GRF (pGRFvert) and peak braking GRF (pGRFbrake) in adults using raw hip activity monitor (AM) acceleration data. The purpose of this study was to develop a statistically based model to estimate pGRF...

PURPOSE Indirect observations suggest that the neural control of accommodation may undergo adaptive recalibration in response to age-related biomechanical changes in the accommodative system. However, there has been no direct demonstration of such an adaptive capability. This investigation was conducted to demonstrate short-term adaptation of accommodative step response dynamics to optically in...

PURPOSE Recent epidemiological research has revealed that gender differences exist in concussion incidence but no study has investigated why females may be at greater risk of concussion. Our purpose was to determine whether gender differences existed in head-neck segment kinematic and neuromuscular control variables responses to an external force application with and without neck muscle preacti...

Classical eye-blink conditioning in mutant mice can be used to study the molecular mechanisms underlying associative learning. To measure the kinetic and frequency domain properties of conditioned (tone - periorbital shock procedure) and unconditioned eyelid responses in freely moving mice, we developed a method that allows adequate, absolute, and continuous determination of their eyelid moveme...

We have examined the kinematics of the initial trajectory of step-tracking movements performed by human subjects. Each subject tracked a target that required 5-30 degrees of radial or ulnar deviation of the wrist. All movements were to be performed as accurately as possible. Speed instructions were given before each trial. When subjects performed different amplitude movements following the same...

We report recent results of experiments and simulations in the regime of peak laser intensities above 10 W/cm, including the following topics: (1) electron and proton acceleration to energies in excess of 10 MeV in well collimated beams; (2) use of laser chirp to control the growth of plasma waves and acceleration of electrons by the Raman instability; (3) all optical injection and acceleration...

This study assesses lateral tipping motion-induced interruptions (MIIs) in a simulated motion environment. The objective is to revisit MII occurrence and sway motion relationship by focusing on the frequency and acceleration of the lateral motion stimulus. Results verify that MIIs increase with increasing peak sway acceleration, but the effect of sway frequency is not as clear as that of accele...