Related Experiment Video
Updated: Dec 25, 2025

Measuring 3D In-vivo Shoulder Kinematics using Biplanar Videoradiography
Published on: March 12, 2021
Cervical kinematics estimated by finite helical axis behaviour differs in patients with neck related problems as
Erik Cattrysse1, Anna Burioli2, Luca Buzzatti2
1Department of Physiotherapy, Human Physiology and Anatomy, Experimental Anatomy Research Group, Vrije Universiteit Brussel, Laarbeeklaan 103, Building B, Room 037, 1090, Brussels, Belgium. Erik.Cattrysse@vub.be.
Abstract:
Purpose The present study analyses the kinematics of patients with neck problems and healthy controls by estimation of Finite Helical Axis behaviour. A cross sectional study design was used to investigate whether FHA behaviour differs due to neck problems.
Methods:
584 subjects were recruited from private and ambulatory institutional physiotherapy practices. Among these 171 patients with neck related problems were selected based on referral diagnosis by primary care general practitioners. Cervical kinematics were compared based on minimal convex hull, path length and mean angle of the Finite Helical Axis distribution as well as on the helical angle. Three active planar motions were registered: flexion-extension, axial rotation and lateral bending.
Results:
Patients demonstrated a significantly reduced and less variable behaviour of the Finite Helical Axis during active flexion-extension and axial rotation motions as compared to healthy individuals and lateral bending.
Conclusion:
Patients with neck related problems demonstrate a more restricted motion behaviour with less variability in Finite Helical Axis distribution and orientation during active planar motions. At present it is not clear whether these kinematic differences are the result or the cause of dysfunction. These slides can be retrieved under Electronic Supplementary Material.
Related Concept Videos
General Case of Eccentric Axial Loading
Consider a member subjected to equal and opposite forces that are applied along a line that does not coincide with the member's neutral axis. In unsymmetrical...
Eccentric Axial Loading in a Plane of Symmetry
Unsymmetric Bending - Angle of Neutral Axis
When a bending moment is applied at an angle θ concerning the vertical axis of a symmetrical member, it can be resolved into components along the member's principal...
Normal Strain under Axial Loading
Muscles that Move the Head
The bilateral sternocleidomastoid, or SCM, and the suprahyoid and infrahyoid muscles are significant head flexors. The SCM muscles originate at the sternum and clavicle and attach to the mastoid process of the temporal bone. The SCM contracts bilaterally to bend the head forward, whereas...
Articulations of the Vertebral Column

