Professor Irvin Korr, writing of his years of osteopathic research described how this red reflex phenomenon was shown to correspond well with areas of lowered electrical resistance, which themselves correspond accurately to regions of lowered pain threshold and areas of cutaneous and deep tenderness.

He cautions:
'You must not look for perfect correspondence between the skin resistance (or the red reflex) and the distribution of deeper pathologic disturbance, because an area of skin which is segmentally related to a particular muscle does not necessarily overlie that muscle. With the latissimus dorsi, for example, the myofascial disturbance might be over the hip but the reflex manifestations would be in much higher dermatomes because this muscle has its innervation from the cervical part of the cord.'

By use of a mechanical instrument which quantified the pressure applied at a constant speed, followed by measurement of the duration of the redness resulting from the action of the frictional stimulator on the skin, Korr could detect areas of intense vasoconstriction which corresponded well with dysfunction elicited by manual clinical examination.

It could be said that the opportunity to 'feel' the tissues was being ignored during all these 'strokes', and 'drawing' of the fingers down the spinal musculature.

This thought was not lost on Marsh Morrison D.C. who describes his views as follows:
'Run your fingers longitudinally down alongside the dorsal and lumbar vertebrae (anywhere from the spinous processes extending laterally up to two inches) and stop at any spot of tissue which seems 'harder' or different from normal tissue. These thickened areas, stringy ligaments, bunched muscle bounds, all represent indurated tissue; they are usually protective and indicate irritation and dysfunction. Once these indurated areas are palpated press down and almost always they will be sensitive, indicating a need for treatment.'

Morrison used a technique for easing such contractions similar to that later described by Lawrence Jones D.O. in his Strain/ counterstrain system.

Osteopathic researchers, Doctors, Cox, Gorbis, Dick and Rogers, writing in 1983 (regarding their work on identification of palpable musculoskeletal findings in coronary artery disease describe their use of the ‘red reflex’ as part of their examination procedures (other methods included range of motion testing of spinal segments and ribs, assessment of local pain on palpation, and altered soft tissue texture). In this study the most sensitive parameters, which were found to be significant predictors for coronary stenosis, were limitation in range of motion and altered soft tissue texture.

‘Red reflex’ cutaneous stimulation was applied digitally in both paraspinal areas [T4 and T9-11] simultaneously briskly stroking the skin in a caudad direction. Patients were divided arbitrarily into three groups.

• a/ Grade 1 - erythema of the spinal tissues lasting less than 15 seconds after cutaneous stimulation.
• b/ Grade 2 - erythema persisting for 15 to 30 seconds after stimulation
• c/ Grade 3 - erythema persisting longer than 30 seconds after stimulation.

In this context the Grade 3 - maintained erythema - is seen to represent the most dysfunctional response.

Making Sense of the Red Reaction
Clearly there is a good deal to learn from and about the simple procedure of stroking the paraspinal muscles. Whether or not DeJarnette's preliminary methods are validated does not alter the possible wisdom of his subsequent observations, employing as it does variable pressures and looking as it does at the fading of redness, rather than the initial red reaction itself, for evidence of altered function.