In a lateral view, if the right shoulder girdle is anterior to the left, which trunk motion would cause that position?

In a lateral view, if the right shoulder girdle is anterior to the left, which trunk motion would cause that position?

• A. Rotation
• B. Flexion
• C. Extension
• D. Lateral flexion

Answer: (A)

Rotation twists the trunk around a vertical axis. When the trunk rotates to the right, the right shoulder girdle moves forward relative to the left, so in a lateral view the right girdle appears anterior to the left. Flexion and extension change the depth of the trunk in the sagittal plane and don’t create a front–back offset between the two shoulders. Lateral flexion tilts the trunk to one side in the frontal plane, which can shift alignment but doesn’t produce one shoulder girdle ahead of the other in a lateral view.

Rotation twists the trunk around a vertical axis. When the trunk rotates to the right, the right shoulder girdle moves forward relative to the left, so in a lateral view the right girdle appears anterior to the left. Flexion and extension change the depth of the trunk in the sagittal plane and don’t create a front–back offset between the two shoulders. Lateral flexion tilts the trunk to one side in the frontal plane, which can shift alignment but doesn’t produce one shoulder girdle ahead of the other in a lateral view.