BACKGROUND Motor imagery and actual movements share overlapping activation of brain areas but little is known about task-specific activation of distinct motor pathways during mental simulation of movements. For real contractions, it was demonstrated that the slow(er) motor pathways are activated differently in ballistic compared to tonic contractions but it is unknown if this also holds true fo...

The mechanisms by which blast pressure waves cause mild-to-moderate traumatic brain injury (mTBI) are an open question. Possibilities include acceleration of the head, direct passage of the blast wave via the cranium, and propagation of the blast wave to the brain via a thoracic mechanism. The hypothesis that the blast pressure wave reaches the brain via a thoracic mechanism is considered in li...

The purpose of this study was to compare the effect of resistance training, static and ballistic stretching and stationary cycling on the range of motion (ROM) and end ROM torque of hip joint flexion, resting tension of the hamstrings and stretch-induced electromyographic (EMG) activity of the hamstrings. Four separate experimental groups performed either 15 min resistance training of the hamst...

One approach to locate the point of fire of a supersonic bullet is to first estimate the trajectory of the bullet and then trace the trajectory back to topographic or man-made obstructions on a digital map. The supersonic flight of a bullet generates a ballistic shock wave, and the trajectory of the bullet can be estimated by measuring the time delay between the shock wave arrivals at each sens...

Controversy exists among the orthopedic community regarding the treatment of gunshot injuries. No consistent treatment algorithm exists for treatment of low energy gunshot wound (GSW) trauma. The purpose of this study was to critically examine the wound contamination following low velocity GSW based upon bullet caliber and clothing fiber type found within the injury track. Four types of handgun...

PURPOSE To create a computer-based numerical simulation model for comparison with empiric paintball-ocular ballistic study findings, allowing identification of the dynamic physical mechanisms (stress, strain, pressure) responsible for intraocular traumatic injury accompanying blunt ocular impact. Virtual experiments with numerical models could exploit mathematical "instrumentation" to facilitat...

Ramp isometric contractions determine peak torque (PT) and neuromuscular activation (NA), and ballistic contractions can be used to evaluate rate of torque development (RTD) and electrical mechanical delay (EMD). The purposes of this study were to assess the number of sessions required to stabilize ramp and ballistic PT and to compare PT and NA between contractions in older adults. Thirty-five ...

The dynamic responses of honeycomb sandwich panels (HSPs) subjected to in-plane projectile impact were studied by means of explicit nonlinear finite element simulations using LS-DYNA. The HSPs consisted of two identical aluminum alloy face-sheets and an aluminum honeycomb core featuring three types of unit cell configurations (regular, rectangular-shaped, and reentrant hexagons). The ballistic ...

The purpose of this study was to compare the effects of plyometric and isometric training on tendon properties during ramp and ballistic contractions and muscle stiffness under passive and active conditions. Eleven subjects completed 12 weeks (3 days/week) of a unilateral training program for the plantar flexors. They performed plyometric training on one side (PLY) and isometric training on the...