Evaluating biomechanics of user-selected sitting and standing computer workstation.

A standing computer workstation has now become a popular modern work place intervention to reduce sedentary behavior at work. However, user's interaction related to a standing computer workstation and its differences with a sitting workstation need to be understood to assist in developing recommendations for use and set up. The study compared the differences in upper extremity posture and muscle activity between user-selected sitting and standing workstation setups.

Effects of Epinephrine Auto-Injector Shape and Size on Human Factors Influencing Drug Delivery.

Objective: The aim of this study was to assess the effects of (a) auto-injector form factor on maximum applied force capability and (b) auto-injector design and instructions on force production and orientation.

Background: Effective delivery of epinephrine through an auto-injector is the result of a multitude of design factors. At minimum, the design needs to allow the user to apply sufficient force for the needle to penetrate clothing and tissue.

Effects of torsion on intervertebral disc gene expression and biomechanics, using a rat tail model.

Study Design: In vitro and in vivo rat tail model to assess effects of torsion on intervertebral disc biomechanics and gene expression.

Objective: Investigate effects of torsion on promoting biosynthesis and producing injury in rat caudal intervertebral discs.

Summary Of Background Data: Torsion is an important loading mode in the disc and increased torsional range of motion is associated with clinical symptoms from disc disruption.

Effects of enzymatic digestion on compressive properties of rat intervertebral discs.

Enzymatic treatments were applied to rat motion segments to establish structure-function relationships and determine mechanical parameters most sensitive to simulated remodeling and degeneration. Rat caudal and lumbar disc biomechanical behaviors were evaluated to improve knowledge of their similarities and differences due to their frequent use during in vivo models. Caudal motion segments were assigned to four groups: soaked (control), genipin treated, elastase treated, and collagenase treated.

In vivo remodeling of intervertebral discs in response to short- and long-term dynamic compression.

This study evaluated how dynamic compression induced changes in gene expression, tissue composition, and structural properties of the intervertebral disc using a rat tail model. We hypothesized that daily exposure to dynamic compression for short durations would result in anabolic remodeling with increased matrix protein expression and proteoglycan content, and that increased daily load exposure time and experiment duration would retain these changes but also accumulate changes representative of mild degeneration. Sprague-Dawley rats (n = 100) were instrumented with an Ilizarov-type device and divided into three dynamic compression (2 week-1.

Validation of lower limb surrogates as injury assessment tools in floor impacts due to anti-vehicular land mines.

The aim of this study was to assess the ability of lower limb surrogates to predict injury due to floor/foot plate impact in military vehicles during anti-vehicular land mine explosions. Testing was conducted using two loading conditions simulated to represent those conditions created in the field. The lower condition was represented by a 24-kg mass impactor with a velocity of 4.