Questioning Fryette

Robert Schleip

Updated Apr 18 2007 

Many osteopaths use the following laws from Harrison H. Fryette, D.O. to assist in the diagnosis of spinal dysfunctions and in the application of their treatment technique:


Law 1: Neutral sidebending produes rotation to the side opposite side of the sidebent, i.e. the sidebending group rotates itself toward the convexity of the sidebend.

Law 2: Non-neutral rotation (i.e. in hyperflexion or hyperextension of the vertebrae) goes in the same direction as the sidebending.

Law 3:Introducing motion to a spinal joint in one plane automatically reduces its mobility in the other two planes.

Fryette formulated his observations in: Fryette HH, Principles of Osteopathic Technic, Academy of Applied Osteopathy, Carmel CA, 1954.

While the first and third law seem to be generally accepted, there is considerable discussion among scientists about the second law. The following excerpt exemplifies this:

„There is evidence to support Freyette’s Laws in relation to sidebending and rotation coupling in the cervical spine, i.e. sidebending and rotation occur to the same side (Stoddard 1969; Mimura et al. 1989). However, the evidence in relation to lumbar spine coupling is inconsistent (Pearcy & Tibrewal 1984; Plamondon et al. 1988; Panjabi et al. 1989; Vincenzino & Twomey 1993). As a consequence, Freyette’s laws may be useful for predicting coupling behaviour in the cervical spine but caution should be exercised for the thoracic and lumbar spine.“ 

(Excerpt taken from:Gibbons P, Teheran P, Gibbons 2001 Spinal manipulation: indications, risks and benefits, Journal of Bodywork and Movement Therapies 5(2):110-119. The references for the original research quoted above are:

  • Mimura M et al.1989 Three dimensional motion analysis of the cervical spine with special reference to the axial rotation. Spine 14: 1135-1139
  • Panjabi M, et al 1989 How does posture affect coupling in the lumbar spine? Spine 14: 1002-1011
  • Pearcy M, Tibrewal S 1984 Axial rotation and lumbar sidebending in the normal lumbar spine measured by three-dimensional radiography. Spine 9: 582-587
  • Plamondon A et al.1988 Application of a Stereoradiographic Method for the Study of Intervertebral Motion. Spine 13: 1027-1032
  • Vicenzino G, Twomey L 1993 Sideflexion and induced lumbar spine conjunct rotation and its influencing factors. Autralian Physiotherapy 39:299-306 )

A systematic review of the scientific literature by Harrison DE et al. concludes "Full three-dimensional investigations of spinal coupling patterns have shown that the vertebrae rotate and translate in all three axes and that previous theories of spinal coupling based upon two-dimensional studies are inaccurate and invalid." (Harrison DE et al. 1998 Three-dimensional spinal coupling mechanics: Part I. A review of the literature. J Manipulative Physiol Ther 21: 101-13)


Edmondston et al. 2007 studied the coupling behavior of the thoracic spine in 53 persons (aged 18-43 yrs) and reported the following findings : there was a common trend towards an ipsilateral pattern in hyperflexed posture, whereas a contralateral pattern was more frequently observed in neutral and hyperextended postures. Yet overall there was a lot lot of variation of the coupling behavior between subjects.(Edmondston SJ et al.2007 Influence of Posture on the Range of Axial Rotation and Coupled Lateral Flexion of the Thoracic Spine. J Manip Physiol Ther 30(3): 193-199 )

Animated article on Freyette's laws by NATA (unfortunately without any reference to the above described scientific discussion)