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Cranial Mechanics
OMM Vault / Cranial Strain Simulator

Cranial Motion & SBS Strain Simulator

Demystify the most failed osteopathic concept on COMLEX. Real-time visual kinematics for all 6 Sphenobasilar Synchondrosis (SBS) strain patterns, the Sutherland 4-finger vault hold, axes of motion, and board vignette traps.

Sutherland Vault Hold & SBS Displacement Top-Down / Coronal Kinematics
SBS JUNCTION SPHENOID BONE OCCIPUT BONE L-IDX Greater Wing L-LIT Squamous Occiput R-IDX Greater Wing R-LIT Squamous Occiput Zygomatic Mastoid Zygomatic Mastoid
Index Finger
Greater Wing (Sphenoid)
Middle Finger
Zygomatic Process (Temporal)
Ring Finger
Mastoid Process (Temporal)
Little Finger
Squamous Portion (Occiput)
Physiologic

Right Torsion

Axes of Motion
1 AP axis (from nasion through SBS to opisthion)
Vault Hold Finger Sensation
Right index finger moves SUPERIOR and ANTERIOR; Right little finger moves INFERIOR and POSTERIOR.
SBS Kinematics & Direction
Sphenoid and Occiput rotate in OPPOSITE directions around the AP axis.
Savarese Board Trap
Torsion is ALWAYS named for the HIGHER greater wing of the sphenoid. 1 AP axis. Opposite rotation.
Mechanism of Trauma
Anterolateral impact to right frontal bone or posterolateral impact to right occiput.

Master Cranial Strain Comparison Table

Complete breakdown of all 6 SBS strains, axes, naming conventions, and trauma vectors.

Strain Pattern Type Axes of Motion Rotation Direction Naming Convention Key Finger Sensation
Torsion Physiologic 1 AP Axis Opposite Higher greater wing of sphenoid One index finger superior/anterior, opposite little finger inferior
Sidebending / Rotation Physiologic 3 Axes: 2 Vertical + 1 AP Opposite (Vertical) / Same (AP) Side of widening / convexity Fingers on one side separate and drop inferiorly (fullness)
Vertical Strain Trauma 2 Transverse Axes Same direction Direction sphenoid BASE moves Superior: Index fingers move inferior. Inferior: Index fingers move superior
Lateral Strain Trauma 2 Vertical Axes Same direction Direction sphenoid BASE shifts "Parallelogram head": Index fingers shift to one side, little fingers to opposite
Compression Severe Trauma AP Axis Compression None (Locked) None (Locked SBS) "Bowling ball head": Hard, rigid, severely diminished CRI amplitude (<4/min)