Reproducibility of the Kinematics in Rotational High-Velocity, Low-Amplitude Thrust of the Upper Cervical Spine: A Cadaveric Study

What is manipulation? A new definition

BACKGROUND

Definitions are important in healthcare. Unfortunately, problems can be found withall existing definitions of manipulation.

METHODS

This paper derives a set of eligibility criteria from prior definitions of manipulation to inform what should (and should not) be incorporated within a valid definition. These criteria were then used to select components from currently available empirical data to create a new definition.

RESULTS

The resulting definition of manipulation is: "Separation (gapping) of opposing articular surfaces of a synovial joint, caused by a force applied perpendicularly to those articular surfaces, that results in cavitation within the synovial fluid of that joint." The corresponding definition for the mechanical response of a manipulation is: "Separation (gapping) of opposing articular surfaces of a synovial joint that results in cavitation within the synovial fluid of that joint." In turn, the action of a manipulation can be defined as: "A force applied perpendicularly to the articular surfaces."

CONCLUSIONS

We believe these definitions to be valid (derived from and consistent with all available empirical data), complete (containing all necessary components), minimally sufficient (minimal redundancy, and sufficient to distinguish manipulation from other physical interventions), and robust (able to withstand important limitations embodied within sensible eligibility criteria). It is hoped that the simplicity and clarity of these definitions, and the transparency of their formation, will encourage their wide adoption in clinical, research, educational and professional settings.

Angular Kinematics of Chiropractic Supine Cervical Spine Manipulation: Rotational Measures and Comparisons to Doctor and Recipient Perceptions

OBJECTIVES

The primary purposes of this study were to measure axial rotation during supine cervical spinal manipulative therapy (cSMT) and to record recipients' and doctors' perceptions of rotational magnitudes.

METHODS

Experienced doctors of chiropractic (DCs) provided supine cSMT and acted as recipients of cSMT. Participants who received SMT wore inertial measurement units attached to the forehead and sternum for motion capture. Afterward, recipients and DCs completed questionnaires asking about their perceptions of motion. Data were analyzed for magnitudes of axial rotation at peak thrust and correlations with patient and doctor perceptions. Secondary analyses included angular velocity, angular acceleration, and other kinematic variables.

RESULTS

We recorded 23 SMT events with 14 DCs. Rotation at thrust peaks averaged 32.4° (17.4°). Doctors' and recipients' perceptions of rotation were higher than measured values 45% and 50% of the time, respectively. Maximum angular velocity and acceleration averaged 221.9°/s (124.9) and 4786.5°/s² (2456.6), respectively. We found no correlation between perceptions and velocity or acceleration; doctors' perceptions had an inverse correlation with measurements.

CONCLUSION

On average, we found rotation during supine cSMT to be 32°. Both DCs and SMT recipients overestimated rotation compared with actual measurements. These factors should be considered in discussions of rotation and SMT.

Analysis of three-dimensional facet joint displacement during two passive upper cervical mobilizations

BACKGROUND

Understanding the 3D-kinematics of the upper cervical spine during manual mobilization is essential for clinical examination and therapy. Some information about rotational motion is available in literature but translational components are often ignored, complicating the understanding of the complex inter-segmental motions.

OBJECTIVES

This study aims to describe the amount, trajectories and reproducibility of atlanto-occipital facet joints' displacement during a flexion-extension mobilization and of the atlanto-axial facet joints during an axial rotation mobilization.

DESIGN

Original research using quantitative data.

METHODS

20 fresh frozen human cervical specimens were examined with a Zebris® CMS20 ultrasound-based motion tracking system. Two physiotherapists performed regionalmobilizations in flexion-extension and axial rotation. The amount of displacement and the trajectories were calculated along the XYZ axes. Difference between measurements was evaluated with the Friedman two-way ANOVA test. Intra- and inter-rater reliability were estimated through ICC scores.

RESULTS

3D-displacement (2.6-23.4 mm) was larger at C1-C2 during axial rotation, Atlanto-occipital flexion displayed the greatest variability in the C0 trajectory. During a right rotation, the left C1 facet moved mainly forward, and the right C1 facet moved backward. During a left rotation, the left C1 facet moved backward, while the right C1 facet moved forward. Intra-tester and Inter-tester ICCs varied between 0.5 and 0.90 (p < 0.005).

CONCLUSIONS

During passive spinal motion, there is an important variability in magnitude and trajectory of joints' displacement. Nevertheless, different clinicians may be able to achieve the same position at the end of the mobilization.

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.

3D motion reliability of occipital condylar glide testing: From concept to kinematics evidence

BACKGROUND

To date, segmental data analyzing kinematics of occipital condylar testing or mobilization is lacking.

OBJECTIVES

The objective of this study was to assess occipitoatlantal 3D motion components and to analyze inter- and intra-rater reliability during in vitro condylar glide test.

METHODS

To conduct this study, four fresh cadavers were included. Dissection was carried out to ensure technical clusters placement to skull, C1 and C2. During condylar glide test, bone motion data was computed using an optoelectronic system. The reliability of motion kinematics was assessed for three skilled practitioners performing two sessions of 3 trials on two days interval.

FINDINGS

During testing, average absolute motion ROM (±SD) were up to 4.1 ± 2.1°, 0.7 ± 1.3° and 10.3 ± 2.5° for occipitoatlantal lateral bending, axial rotation and flexion-extension, respectively. For position variation, magnitudes were 2.3 ± 1.8 mm, 1.1 ± 1.3 mm and 2.6 ± 0.8 mm for anteroposterior, cephalocaudal and mediolateral displacements. Concerning motion reliability, variation ranged from 0.6° to 3.4° and from 0.3 mm to 1.6 mm for angular displacement and condyle position variation, respectively. In general, good to excellent agreement was observed (ICC ranging from 0.728 to 0.978) for the same operator, while consistency was limited to lateral/side bending and lateral condyle displacement between operators, with respective ICCs of 0.800 and 0.955.

CONCLUSIONS

This study shows specific motion patterns involving extension and lateral bending of the occipitoatlantal level for anterior condylar glide test. In addition, condyle position variation demonstrated coupled components in forward and heterolateral directions. However, task seems not to be side specific. In general, reliability of 3D motion components showed good intra-operator agreement and limited inter-operator agreement.