Biomedical subjects

Laurence Chèze

Publications and source records attributed to Laurence Chèze.

2 recordsLinked to original sources

PubMed2005

Rotation sequence as an important factor in shoulder kinematics.

BACKGROUND: The International Society of Biomechanics has proposed a standardization recommendation for motion recordings of the upper extremity defining the set of bony landmarks, local coordinate systems and joint coordinate systems. The aim of our study was to verify the clinical interpretation of the proposed rotation sequence for the glenohumeral joint and to compare it with other sequences. METHODS: Fifteen glenohumeral movements in their maximal ranges were tested on five healthy subjects. The movements were separated into five groups (flexion, extension, abduction, horizontal flexion and circumduction) with three humeral rotation positions (full external, full internal and neutral). Four glenohumeral rotation sequences were constructed using YXY, YXZ, ZXY and XZY orders and angle amplitudes were examined in terms of gimbal lock and amplitude coherence. FINDINGS: The results of the gimbal lock incidence and amplitude coherence should be taken into account together. Therefore, the suitable rotation sequences for all rotation variations of abduction and extension were found and no tested rotation sequence was found to be clinically interpretable for all tested movements. INTERPRETATION: Before glenohumeral three-dimension experiments the choice of the rotation sequence should be made in agreement with the no-gimbal lock incidence and amplitude interpretability of the performed movements.

Adult↗

PubMed2004

A three-dimensional kinematic and dynamic study of the lower limb during the stance phase of gait using an homogeneous matrix approach.

This paper presents a method to analyze three dimensional kinematics and dynamics of lower limb during walking. The proposed method is based on a homogeneous matrix concept, derived from robotics and using compact, expressive notation convenient for computer applications. The major advantage of this method is that no hypothesis is required on the joint model, which makes it applicable to complex and pathologic joints. Kinematic data are computed from 3-D trajectories of markers collected by a motion analysis system. External forces applied on the leg are measured synchronously during the stance phase of gait. Angular velocity components obtained using the homogeneous matrix method are displayed for three subjects and compared with those obtained from the same experimental data using a helical axis method. Then, intersegmental moments calculated from the inverse dynamic part of the homogeneous matrix method are shown on the same subjects. Kinematic results indicate that there are no significant differences between the methods, thus demonstrating the reproducibility of the stance phase of gait in the sagittal plane. Use of this synthetic homogeneous method developed for both kinematics and dynamics of rigid bodies demonstrates good promise for applications in biomechanics.

Adult↗