Figure 1

Summary of subject movement measurements. (a) Lower cervical spine flexion: the change in angle from a line extending from C7 to the tragus of the ear (T) and a vertical line through C7. (b) Upper cervical spine extension: the change in angle from a line extending from the tragus to the mid forehead (MF) and a vertical line through the tragus. (c) Protraction: the change in distance of the acromion (A) along the horizontal axis. (d) Trunk flexion: the change in angle from two lines extending from L1 to the acromion (A) and L1 to the greater trochanter (GT).