b'CODING Update ComplianceLEGAL NUTRITIONUpdateANJC NewsANJC Leadership ANJC News! NUTRITION LEGAL EASEANJC Scholarships REHAB Update CHIRO AssistExecutive Directors Update LEGAL Q&A2020 ANJC AWARDSINSURANCE Update INSURANCE Update Legislative UpdateTECHNIQUE Update Factors of EffectiveHVLA Adjustments: By Dr. David GraberDelivering an Effective ForceMedicareQ&AMedicare Update The success of high-velocity low amplitude OUR HEALTH(HVLA) adjustments ultimately comes down to delivering an effective force.Your palpation can be spot on, your setup perfect, and your patient sufficiently relaxed. However, if you dont deliver a proper force, your adjustment will fail to produce the results you and your patient desire.In Physics 101 we all learned Newtons second law of motion by the formula: F = MA.Force (F) is equal to mass (M) multiplied by acceleration (A).A doctors mass is constant (though many of us would like it to be less constant!) as is the patients.Acceleration is the change in velocity or speed, divided by time.For HVLA adjustments, thats the time it takes to go from the preload/pre-thrust phase to peak force generation in the thrust or impulse phase.for a longer duration.The second is to mobilize the joint by In general, smaller-sized doctors would need to apply morerhythmically engaging the restrictive barrier in an oscillating speed to generate the same force of a larger doctor to movemanner.Finally, use a smaller magnitude of preload prior to a bone at rest.This is more of a factor for those techniquesthrusting, such as is done with many techniques utilizing a that address larger areas of the body that need to bedrop piece or recoil type of adjustment.In all of the above physically positioned by the doctor, and require a good dealmethods, its critical that the patient remains relaxed andof preload.at ease.Adjusting techniques begin by positioning the patient asIn the thrust/impulse phase, speed counts.The faster the a whole, and the articulation to be adjusted in particular,HVLA impulse or thrust, the more joint afferentation and in the most anatomically advantageous position.Having amuscle spindle stimulation occurs.The speed at which the well-made table with at least the ability to vary the angle ofjoint separates and gaps causes cavitation.Faster thrusts the headpiece and abdominal section will help enormouslycause more gapping.Research has shown that experience in this regard.A chiropractor should consider their adjustingand expertise tend to lead to faster impulses.table an investment and be willing to spend more money on it than any other piece of equipment in their office. The doctor needs their own body to be a solid base to adjust from.Stable footing, core stiffness, relaxed shoulders, and good physical alignment during the adjustment is fundamental.Its essential for not only the delivery of a good adjustment, but also in limiting the stress on the doctors body.Chiropractic HVLA adjusting is demanding over ones career.Doctors should also be engaging in a regular (if not daily) conditioning program to stay in peak form.A sweet spot exists for the amount of force applied that gives the most beneficial effect.The total force delivered during an adjustment comes from the combination of forces in the preload/pre-thrust phase and the thrust/impulse phase.An adjustment invokes the Goldilocks Principle, whereby too much or too little preload or bodyweight is counter-productive to a good HVLA adjustment.There are three ways to optimize an HVLA adjustment in theThe actual duration in the thrust phase of an HVLA adjust-preload/pre-thrust phase prior to administering a thrust orment is under 100 ms., essentially faster than the blink of an impulse.The first is by holding the contact at the end rangeeye (~100ms.).Studies in the cervical spine have shown the 12 I Summer 2021 www.anjc.info'