Comparison of High Velocity Low Amplitude Manipulation With Cavitation Verses Non-Cavitation: Effect Upon Atlanto-axial Rotation Asymmetry in Asymptomatic Subjects

Abstract

High velocity thrust techniques are widely used by manual medicine practitioners in an attempt to improve the quality and range of motion available at a particular spinal segment. Generally, high velocity thrust techniques are accompanied by a “pop” or “crack” representing cavitation within the zygapophyseal joint. Some authors argue that the “noiseless” thrust has equal therapeutic effect to those accompanied by cavitation. The aim of this study was to determine whether high velocity thrust manipulation of the atlanto-axial joint ameliorated pre-existing atlanto-axial rotation asymmetry in asymptomatic subjects and compare this to the effects of a sham thrust technique without cavitation. A convenience sample of twenty asymptomatic subjects were recruited for the study. Measures were taken pre-manipulation and five minutes post-manipulation. All subjects demonstrated mild atlanto-axial rotation asymmetry and received a single atlanto-axial rotation manipulation in the direction of the restricted rotation range. Thirteen subjects received manipulation to the atlanto-axial joint with cavitation and seven received a thrust technique with no audible cavitation. The results indicate that mild cervical rotation asymmetry is a normal variant within the population. While there was a trend towards amelioration of rotational asymmetry in both the cavitation and non-cavitation groups neither reached significance (cavitation p >0.1; non-cavitation p>0.5)

Keywords::

• Manipulation
• HVLA
• atlanto-axial joint
• high velocity thrust
• sham manipulation