A technique observing contour lines of an object by the use of moiré is developed. Shadow of an equispaced plane grating is projected onto an object by a point source and observed through the grating. The resulting moiré is a contour line system showing equal depth from the plane of grating if the light source and the observing point lie on a plane parallel to the grating. A technique to wash away the unwanted aliasing moiré optimization of contour line spacing and visibility and the results of the application are described.

Impairments in cervical kinematics are common in patients with neck pain. A virtual reality (VR) device has potential to be effective in the management of these impairments. The objective of this study was to investigate the effect of kinematic training (KT) with and without the use of an interactive VR device. In this assessorblinded, allocation-concealed pilot clinical trial, 32 participants with chronic neck pain were randomised into the KT or kinematic plus VR training (KTVR) group. Both groups completed four to six training sessions comprising of similar KT activities such as active and quick head movements and fine head movement control and stability over five weeks. Only the KTVR group used the VR device. The primary outcome measures were neck disability index (NDI), cervical range of motion (ROM), head movement velocity and accuracy. Kinematic measures were collected using the VR system that was also used for training. Secondary measures included pain intensity, TAMPA scale of kinesiophobia, static and dynamic balance, global perceived effect and participant satisfaction. The results demonstrated significant (p<0.05) improvements in NDI, ROM (rotation), velocity, and the step test in both groups post-intervention. At 3-month post-intervention, these improvements were mostly sustained; however there was no control group, which limits the interpretation of this. Between-group analysis showed a few specific differences including global perceived change that was greater in the KTVR group.This pilot study has provided directions and justification for future research exploring training using kinematic training and VR for those with neck pain in a larger cohort.  The results demonstrated significant improvements in NDI, ROM, velocity, and the step test in both groups, with a few specific between-group differences including global perceived change that was greater in the VR group. This pilot study has provided directions and justification for future research exploring training using kinematic training and VR for those with neck pain.

The Flexion-Rotation Test (FRT) is proposed to assess mobility primarily at C1-C2. However, there is no in vivo measurement investigating the validity of the FRT. The purpose of this study was 1) to examine measurement reliability of segmental upper cervical movements using magnetic resonance imaging and 2) to investigate the content validity of the FRT. Nineteen asymptomatic female subjects (mean age: 22.2 years) were evaluated with a 0.2-T horizontally open MRI unit. The segmental rotation angles from Occiput-C1 to C3-C4 and the C4 vertebra were assessed with the head maximally rotated to both the right and the left in two conditions - neck in neutral and in flexion. Good reliability of the method of measurement was suggested by error considerations. A repeated measure ANOVA revealed an interaction between the two different neck starting positions and segment levels (P < 0.0001). Post-hoc analysis revealed that there were significant reductions in the flexed position (P < 0.0001) except for at Occiput-C1. While there was only a 16.3% reduction in rotation range at C1-C2, the reduction was 68.1% at C2-C3, 61.4% at C3-C4, and 76.9% at segments below C4, respectively, supporting the content validity of the FRT as a clinical measure of atlanto-axial mobility.

Contour moiré pictures with good contrast of a full size living body are now available. Construction problems, performance, and accuracy of large instruments are experimentally studied. Techniques to minimize the drawbacks of the moiré contouring are developed. The system has been proved to be ready for practical application to full size living bodies.