Non-Neutral (Type II) Vertebral Somatic Dysfunction

The specific dysfunction is labeled by the position the zygapophyseal joint is stuck in and the asymmetrical position the segment assumes when it is moved in the direction of restricted motion. The three-dimensional motion restricted at the vertebral segment is diagonally opposite to the diagnostic label given to the dysfunction. There are four potential positional diagnoses for single quadrant limitations of segmental motion: ERSR, ERSL, FRSR and FRSL. These diagnoses are based upon osteopathic terminology and are commonly used in muscle energy and joint mobilization systems of treatment.

FRSR - Flexed, Rotated and Side bent to the Right

This term describes the asymmetrical movement of the superior vertebra during extension of the segment if the left zygapophyseal joint is unable to close (the inferior articular process of the superior vertebra is unable to glide inferior on the superior process of the inferior vertebra). If the left zygapophyseal joint is stuck in an open or flexed position (it can not extend), the superior vertebra will side bend to the right as the segment is extended. In accordance with Law II, the superior vertebra will also rotate to the right. The right rotation of the superior vertebra will cause its right transverse process to move posterior in relation to the left transverse process and the right transverse process below. The posterior position of the right transverse process of the superior vertebra can be palpated with the patient in an extended spinal posture. When a zygapophyseal joint is unable to close with extension, the posterior transverse process will be on the opposite side as the zygapophyseal joint that is stuck. The positional diagnosis would indicate that the superior vertebra is Flexed, Rotated and Side bent to the Right. This dysfunction at the L4/5 segment would be recorded as L4 FRSR. The restricted motion at the segment is Extension, Rotation and Side bending to the Left. If using a direct treatment technique like muscle energy, the motion restricted will be the three-dimensional direction the dysfunctional segment is moved toward during treatment.
Posterior view
Superior view