Research Article

In Vivo Spinal Posture during Upright and Reclined Sitting in an Office Chair

Figure 1

Wooden MRI-compatible prototype office chair in the upright (a) and the reclined positions (b), together with the corresponding MR images of subject 2, the only subject exhibiting vertebral degenerative changes (at the level L5-S1) (bottom), including the calculated parameters (c). Coordinate system (red arrows), lumbar ( ), thoracic ( ), and cervical ( ) curvature angles (green), exemplary wedge angle of TH9/TH10 ( ), and quadrangle constructed using the two endplates and the ventral and dorsal margins of the vertebral body to calculate the midpoint of each vertebra (blue quadrangle).
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(a)
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(b)
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(c)
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(d)