The development of the Scgmental Drop System of adjusting the human body began in the late 1940's. when Dr. J. Clay Thompson was a student attending Palmer School of Chiropractic. Dr. Thompson was not pleased with the system of adjusting on a solid headpiece, whether on the knee chest or side posture tables. He wanted to reduce the reflected energy into the doctor's arms from the thrust to the patient's atlas, and improve on the action of the adjustment to the patient. He came up with a spring loaded swivel drop headpiece, with a locking mechanism that held the swiveled piece down until ready for the next adjustment. The drop system of adjusting has been studied by any number of researchers, and it's interesting to note that many people do not realize how little force it takes to accomplish an adjustment. There were two studies by Dr. Arthur Adams and Dr. James Wood, conducted in 1984. published in the Palmer College Research Forum, and reported in the proceedings of the 14lh Annual Biomechanics Conference on j the Spine. Here is the abstract of the first study, file #239, if you wish to review it, and the second file #240. Abstract: Thirty-seven chiropractors (average practice experience eight years) performed six thrusts consisting of three sets of two adjustments, the adjustments differing only with the contact hand used. One thrust with each hand was obtained with the chiropractor thrusting as hard as possible on a rigid tabletop. The four remaining thrusts were performed on an adjusting simulator, using Thompson Technique for the correction of right and left posterior ilium sub-luxations, and right and left posteriorly rotated fifth lumbar subluxations. Each chiropractor was asked to estimate the force they use when adjusting the lumbo-pelvic spine. A flexible transducer (Moss Rehabilitation Hospital, Philadelphia. Pa.) and storage oscilloscope (Tektronix T912) were used to measure adjusting force magnitude as a function of time. Impulse was obtained by integrating recordings for each thrust or force vs. time with a polar planimeter. Thrust duration, and impulse were determined for each thrust. There were no significant differences in force magnitude between right and left hand contacts for any of the three sets of thrusts, but the amplitudes of forces developed in each set of thrusts differed significantly from those of other sets. Duration of thrusts were similar for right and left hand contacts in each of the three types of thrusts and, in most cases, did not significantly differ. Impulses were not statistically different for the same right and left hand contact simulated adjustments, but the values for maximal thrusts on the rigid surface differed significantly from values for thrusts on the adjustment simulator. The four simulator thrusts were not significantly different from each other. In the event you want to read through research papers, you should be aware of the methodology and mathematics utilized by researchers. When you get right down to it, the average chiropractor uses about 35 pounds of force for about 1/10th of a second on the drop table. We come to this conclusion basing our information on the newton, the international standard for measuring force, which equals 102 gram weights (GWT). One pound is equal to 454 GWT. Dividing 454 by 102, we get 4.45 newtons; therefore, one pound equals 4.45 newtons. As an example, if we have a measured thrust of 155.75 newtons, this would equate to 35 pounds of force. Then, factor in impulse pound-per-second, and the resultant force would be about 10-to-16 pounds for the measured duration of about .2-to-.3 seconds. Dr. Thompson predicated his invention of the process of drop adjustment on Newton's Second Principle, which states that the forces used in the adjustment have an inverse relationship to each other, creating a special process of adjustment of the human body. In researching the Newton papers, 1 found where Newton had postulated that a force applied to an object would result in a change of position of the recipient of that force or energy applied, and the factor of force would be inversely proportional. The Segmental Drop Style of chiro practic adjustment also embraces an analysis system based on the early work of Dr. Romer Derifield, of Detroit, Michigan. The neurological basis arises from the inhibitory/facili- tory system that is located in the retic- ular formation of the brain. This neu rological system is the basis for bal ancing of the musculature that controls the posture of the skeletal system, nec essary for day-to-day activities we per form. ' Derifield had noted, during the course of patient treatment, that vari- ous adjustments to the pelvic region changed the length of his patients' legs, as the short leg would equalize with the other leg—referred to in today's literature as Leg Length Inequality (LLI). During the course of his investigation, he found that there were times when, no matter what he did to the pelvis, the leg length would not be maintained after the adjustment to the pelvic region. The story goes, as related to me by Dr. Thompson, that, one day. Dr. Deri-field was taking care of a patient when the phone rang. His desk was located in the adjusting room, and as he answered the phone, he turned to the patient, for whom the call was intended. As the patient raised his head and looked toward Dr. Derifield, the doctor noted that there was a shift in the patient's leg length. After the call was completed, Dr. Derifield had the patient turn his head from left to right, and noted the change in the short leg as he turned his head. It is not known for sure what the analysis was at that time. but that was the beginning of a systematic analysis technique that has survived to this very day. The test demonstrated to Dr. Deri field that cervical subluxations do have an effect on the ilium low back, and Leg Length Inequality. It was several years later that Drs. Thompson and Deri field became acquainted, during a meeting of chiropractors which, more than likely, occurred at Palmer's Lyceum which is held in August of every year. There are a number of specifics that have been lost with the passing of those who set the course in our profession and, if anyone has more definitive historical information on Drs. Derifield and Thompson, I. for one, would appreciate their sharing it with me. Dr. Wciyne Henry Zemelka is a 1975 graduate of Palmer College of Chiropractic and is certified in Video Motion X-ray {Videofluoroscopy) and the Thompson Technique. He studied Videofluoroscopy under Dr. Vern Pierce and received his Certification from Palmer College. He studied the Thompson Technique under Dr. J. Clay Thompson. Dr. Zemelkci is retired from full time teaching at Palmer College and operates the Zemelka Familx Chiropractic Center in Davenport, Iowa. He still teaches the Thompson Technique at seminars throughout the world. You may contact him at: ilrwttyiw® iwlins.net or visit his web site at: hltn://\\uw.m>liiis.ncl/sh<n\cascAhiroheahli References 1. Guylon, Arthur C. Textbook of Medical Physiology.. 7th ed. Philadelphia:Saunders, 1986 Arthur A. Adams. D.C.. F.I.C.R.. James Wood. PhD.. F.I.C.R. Forces used in the selected chiropractic adjustments of the low- back: a preliminary study: PCC Research Forum. Autumn. 1985 Dr. Wayne Henry Zemelka presents the Thompson Technique, Victoria Press. February. 1992 Sir Isaac Newton-1642-1 727. A short account of the history of mathematics (4l" edition. 1908). bv WAV. Rouse Ball o
