Coymo

Sammanfattning

This report is part of a Bachelor’s degree corresponding to 15 credits

at the Royal Institute of Technology, Stockholm. The work has

been carried out by Max Wikander, author of the report, supervised

by Lanie Gutierrez-Farewik and Erik Dijkstra.

Gait analysis includes measurement, characterization and assessment

of human movement and is used to assess kinematic or other

abnormalities during gait. Center of rotation and the axis of rotation

of a joint are fundamental parameters in motion analysis. However,

the ability to create individualized analysis is limited by the lack of

accuracy when these parameters are calculated. Therefore, the ability

to improve and innovate methodology used to calculate the joint center

of rotation is evaluated.

A number of movements including gait was examined using infrared

technology at Karolinska University Hospital in Stockholm. During

the measurements self-constructed clusters of markers were used. This

report presents the results and analysis of these measurements. Kinematic

models to describe the knee and hip motion and compute the

center of rotation of these joints are formulated and evaluated.The

models are partly based on the literature study performed in the beginning

of the project. To begin with, a model adapted to movement

with a static center of rotation is formulated. The static model is then

developed to be applicable in the case of a moving center of rotation.

Both models are applied to the measurements conducted. A three-dimensional

model is briefly described and is considered suitable for

further development of the project.

The results show that the models are applicable to various movements

including gait. A comparison with the software currently used

at Karolinska University Hospital indicates that the model adapted to

plane motion provides reasonable results. However, no assessment of

the model’s precision can be made as this would require some form of

medical imaging or invasive techniques.