Ideal

• EOP is on plumb line

You See

• EOP is off plumb line and/or SP C₇ is on plumb line – head is laterally flexed
• EOP is off plumb line and/or SP C₇ is on other side of plumb line – head is rotated to OS and spine is rotated, or spine is laterally flexed

Likely Cause

Head is rotated

• Short neck rotators to that side (and/or long neck rotators OS, also see head is rotated
• Spine is rotated to that side
• Leg is laterally rotated and OS leg is medially rotated

Head is laterally flexed

• Short neck lateral flexors
• Habitual leaning to that side
• Short (lumbar) spine lateral flexors
• Longer leg