Biomechanical effects of a lumbar support in a mattress.

For many patients with chronic low back pain, the lack of sleep and sufficient rest period that allows some relaxation is a major obstacle to a good quality of life. During sleep periods, neuromuscular activity is at a minimal level. The major factor influencing the forces on the body, and particularly the spine, is gravity.

Measurement of the pressure applied during motion palpation and reliability for cervical spine rotation.

Objective: To measure the pressure applied during motion palpation for cervical spine rotation and to verify its effect on reliability when the kinematics of the test are standardized.

Methods: The pressure of palpation used during the test of cervical spine rotation was measured by means of flexible and extra-fine pressure sensors linked to an electronic interface. Seven pressure measurements (left rotation from C1 to C7) for each of 24 examiners were taken.

Comparison of mechanical force of manually assisted chiropractic adjusting instruments.

Objective: To quantify the force-time and force-delivery characteristics of six commonly used handheld chiropractic adjusting devices.

Methods: Four spring-loaded instruments, the Activator Adjusting Instrument; Activator II Adjusting Instrument, Activator III Adjusting Instrument, and Activator IV Adjusting Instrument, and two electromechanical devices, the Harrison Handheld Adjusting Instrument and Neuromechanical Impulse Adjusting Instrument, were applied to a dynamic load cell. A total of 10 force-time histories were obtained at each of three force excursion settings (minimum to maximum) for each of the six adjusting instruments at preload of approximately 20 N.

The kinematics of motion palpation and its effect on the reliability for cervical spine rotation.

Background: The reliability of a test depends on its standardization. Instrumental measurement of the reproducibility of the test is an effective way to evaluate the level of standardization obtained. Improved standardization is believed to yield greater reliability.

Reliability and measurement error of the BioTonix video posture evaluation system--Part I: Inanimate objects.

Objective: To investigate the reliability, concurrent validity, and error of a new video digitizing system for evaluating posture when applied to inanimate objects.

Design: Delayed repeated measures of digital images of inanimate objects.

Setting: University laboratory.