A preliminary repeated measures study of the effect of an imposed posture on the pose of the head and upper and lower neck of seated humans.

Background: Posture of the upper neck is considered by some to contribute to neck pain and headache. Infrared reflectors and cameras permit non-invasive three-dimensional (3D) evaluation of head and neck range of motion but have not been used to examine the relative pose (position and orientation) of the head, upper and lower neck.

Research Question: Can the relative 3D pose of the head, upper and lower neck regions of adult humans be non-invasively measured and perturbated while recording the characteristics of neck or head pain?

Methods: An optical motion capture system was used in a repeat measure descriptive analysis study.

The evaluation of inhalation studies for exposure quality: A case study with formaldehyde.

The inherent complexity of generating and monitoring a test article in an inhalation chamber can make inhalation toxicity testing challenging. Poor study design, human error, and electrical and mechanical problems can adversely affect an inhalation exposure and undermine a study's results. We have developed a process for evaluating seven key elements of exposure quality in inhalation chamber studies: 1) test article characterization, 2) generation method, 3) chamber sampling and analytical method, 4) chamber concentrations, 5) particle size characteristics, 6) chamber type, and 7) controls.