Figure 4. Motion displacement relative to the neutral positions of the vertebral landmarks and corresponding skin markers on the C2 (red), C5 (green), and C6 (blue) levels in X (A), Y (B), and Z (C) direction during lateral bending.

C2-vertebral landmarks: dashed line; C2-skin markers: dotted line; C5-vertebral landmarks: dash dotted line; C5-skin makers: short dash dotted line; C6-vertebral landmarks: short dashed line; C6-skin markers: short dotted line.