Fig. 2From: An observational study of quality of motion in the aging cervical spine: sequence of segmental contributions in dynamic fluoroscopy recordingsSeparate frames of an extension cinematographic recording. Four out of 52 frames of the movement are displayed, starting from maximum flexion (left) to maximum extension (right). Annotation of the vertebrae C4 to C7 in each separate frame with manual corrections are displayed. Relative rotations of the segments are calculated based on these annotationsBack to article page