Article

A new upper extremity model is introduced for clinical application. It combines
the advantages of functional methods to determine the joint parameters for the
shoulder joint centre and the elbow axis location with the ease of a minimal skin
mounted marker set. Soft tissue artefacts at the shoulder and upper arm are
reduced via a coordinate transfer between dynamic calibration and the actual
motion analyzed. A unique technical frame linked to markers on the forearm is
defined for the humerus. The protocol has been applied to 50 subjects over a wide
age range (5-85 years) and with varying physical status, proving clinical
feasibility. Variability in joint centre localization in repeated measures was
typically below 1 cm. Based on these estimated joint centre locations for
shoulder and elbow, three shoulder joint angles together with elbow flexion and
forearm pro-/supination were determined in a large set of static arm postures in
5 subjects. These were compared to synchronous universal goniometer measurements
to analyse intra-tester, inter-tester, and inter-subject repeatability.
Differences between the computed angles and the angles obtained directly with the
goniometer remained below +/-5 degrees for joint angles up to 120 degrees and
+/-10 degrees above 120 degrees.

Langue : ANGLAIS