By William M. Maykel, DC, DIBAK
Presented at the International College of Applied Kinesiology-USA
Proceedings of the Annual Meeting, Winter, 1984, p. 77

Abstract: The height of calcaneal elevation has a direct effect on the ability of the nervous system to maintain peripheral muscle strength. It is readily demonstrable using muscle testing and a measuring wedge that each individual has a certain fixed capacity for calcaneal elevation (calcaneal tolerance factor) beyond which point every muscle in his body becomes weak. Preliminary studies have shown this to occur between 1.25 and 1.5 inches in most cases. This author feels that all patients should be screened for their individual tolerance factor and footwear changed accordingly.

Introduction: Early in practice a friend and musician presented himself for treatment of a severe recurrent torticollis. He had been treated chiropractically on an average of two to three times a week for seven years for this problem. It seemed as though every night while dancing on stage, singing and playing the guitar, he would experience his neck muscles going into severe spasm, which worsened as the might progressed. Upon questioning, he told me that he routinely wore boots with a three inch heel. I had him back up to that approximate height on a pair of DeJarnette blocks and found to my astonishment that every neck and shoulder muscle was markedly weakened.

Eradication of his heels corrected the problem and he has had no recurrence. Testing people on the DeJarnette blocks became commonplace in our office after this experience and has proven to be a useful screening tool to help solve “ another piece of the puzzle.” In an effort to more accurately and safely measure this calcaneal tolerance factor, I devised a stainless steel wedge – The Heal Helper. The wedge can measure elevation to a maximum of four inches and has both metric and customary markings.

The mechanism of this observation may be linked to dural stress. With the dura mater connected to the occiput, C1, C2, and again at S2, it would seem reasonable to assume a stretch of the entire spinal cord is occurring with advancing calcaneal elevation. It is interesting to note one exception with respect to this. The only person tested who was actually stronger in a three-inch heel than in a level position was a woman with a spinal fusion at L5/S1. Evidently her nervous system had adapted to the change in her spinal cord length.

In practice the number of diverse problems potentially related to this factor is enormous. Changes in footwear with the subsequent spinal and peripheral muscle strength changes have helped solve muscle and joint problems in virtually every area of the body. In conclusion, I respectfully submit that all patients should be made aware of their own calcaneal tolerance factor and proceed to adjust their footwear accordingly.