Article

Previous studies reported passive cervical range of motion under
unknown loading conditions or with minimal detail of subject positioning.
Additionally, such studies have not quantitatively ensured the absence of active
muscle during passive measurements. For the purpose of validating biomechanical
models the loading condition, initial position, and muscle activation must be
clearly defined. A method is needed to quantify the passive range of motion
properties of the cervical spine under controlled loading conditions,
particularly in the pediatric population where normative clinical and model
validation data is limited. METHODS: Healthy female pediatric (6-12years; n=10),
male pediatric (6-12years; n=9), female adult (21-40years; n=10), and male adult
(20-36years; n=9) volunteers were enrolled. Subjects with restrained torsos and
lower extremities were exposed to a maximum 1g inertial load in the
posterior-anterior direction, such that the head-neck complex flexed when
subjects relaxed their neck musculature. Surface electromyography monitored the
level of muscle relaxation. A multi-camera 3-D target tracking system captured
passive neck flexion angle of the head relative to the thoracic spine. General
estimating equations detected statistical differences across age and gender.
FINDINGS: Passive cervical spine flexion equaled 111.0 degrees (SD 8.0 degrees )
for pediatric females, 102.8 degrees (SD 7.8 degrees ) for adult females, 103.8
degrees (SD 12.7 degrees ) for pediatric males, and 93.7 degrees (SD 9.9 degrees
) for adult males. Passive neck flexion significantly decreased with age in both
genders (P<0.01). Females exhibited significantly greater flexion than males
(P<0.01). INTERPRETATION: This study contributes normative data for clinical use,
biomechanical modeling, and injury prevention tool development.
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS