Table 1.

Rules of thumb commonly used to identify spinal landmarks

Landmark	Rule of Thumb
C1	Transverse of Atlas Found Palpating Down and in From Inferior Tip of the Mastoid Process
C2	Large Bifid SP
C3	Usually the Smallest Vertebra in the Spinal Column
C6	Last Freely Movable Spinous in Cervical Region Upon Flexion-Extension
C7/T1	Longest Cervical SP. C7, 60%-70% of the Time; T1, 30%-40% of the Time
T3	Found at Spines of the Scapulae
T4 and T5 Intervertebral Disk	Sternal Angle, Patient Supine
T6	Found at the Level of the Tip of the Scapula, Patient Prone
T7	Found at the Level of the Tip of the Scapula, Patient Sitting or Standing
T10	Xiphisternal Junction
L1	First Large Blade-Like SP
L4	Across From the Crest of the Ilium When Prone
S2 (Second Sacral Tubercle)	Level With or Slightly Below the PSIS