What's The "Crack" Sound?
2- 1.89 mm +/- 0.59 mm STD
2. Joint duration was less than the duration of single frame (<310 milliseconds)
3. Rapid cavity inception associated with crack and joint separation
4. Fluid brings in gas in solution for formation of air region
5. Results show joint cracking is the result of cavity inception within synovial fluid
6. Resultant cavity (air region) never collapsed past the point of sound production
Safety of tribonucleation in physiologic conditions:
Old thought of the “cracking” noise experienced during distraction of a joint was based off xray static images with too long of time between images to accurately depict the events of the “crack”. Then using cine MRI (motion xray of sorts), new evidence showed that it is the formation of gas bubbles from dissolved gas in a solution when distraction forces are applied (friction coefficient is exceeded). I noticed the relationship between this phenomenon – Viscous Adhesion aka Tribonucleation, to what occurs during a chiropractic adjustment described by several authors in research and employed clinically in practice getting results.
Brandon Hodges, Doctor of Chiropractic graduated from Life Univeristy in Atlanta, GA December 21, 2013.