Assessment of in vivo 3D kinematics of cervical spine manipulation: Influence of practitioner experience and occurrence of cavitation noise.

BACKGROUND: Investigations on 3D kinematics during spinal manipulation are widely reported for assessing motion data, task reliability and clinical effects. However the link between cavitation occurrence and specific kinematics remains questionable.

OBJECTIVES: This paper investigates the 3D head-trunk kinematics during high velocity low amplitude (HVLA) manipulation for different practitioners with respect to the occurrence of cavitation.

METHODS: Head-trunk 3D motions were sampled during HVLA manipulation in twenty asymptomatic volunteers manipulated by four practitioners with different seniority (years of experience). Four target levels were selected, C3 and C5 on each side, and were randomly allocated to the different practitioners. The data was recorded before, during and after each set of trial in each anatomical plane. The number of trials with cavitation occurrence was collected for each practitioner.

RESULTS: The manipulation task was performed using extension, ipsilateral side bending and contra-lateral axial rotation independent of side or target level. The displayed angular motion magnitudes did not exceed normal active ROM. Regardless cavitation occurrence, wide variations were observed between practitioners, especially in terms of velocity and acceleration. Cavitation occurrence was related to several kinematics features (i.e. frontal ROM and velocity, sagittal acceleration) and practitioner experience. In addition, multilevel cavitation was observed regularly.

CONCLUSIONS: Kinematics of cervical manipulation is dependent on practitioner and years of experience. Cavitation occurrence could be related to particular kinematics features. These aspects should be further investigated in order to improve teaching and learning of cervical manipulation technique.