Consistency and malleability of manipulation performance in experienced clinicians: a pre-post experimental design

The purpose of this study was to sample the stability of spinal manipulation performance in peak impulse force development over time and the ability of clinicians to adapt to arbitrary target levels with short-duration training.

A pre-post experimental design was used. Human analog mannequins provided standardized simulation for performance measures. A convenience sample was recruited consisting of 41 local doctors of chiropractic with 5 years of active clinical practice experience. Thoracic impulse force was measured among clinicians at baseline, after 4 months at pretraining, and again posttraining. Intraclass correlation coefficient values and within-subject variability defined consistency. Malleability was measured by reduction of error (paired t tests) in achieving arbitrary targeted levels of force development normalized to the individual's typical performance.

No difference was observed in subgroup vs baseline group characteristics. Good consistency was observed in force-time profiles (0.55 ≤ intraclass correlation coefficient ≤ 0.75) for force parameters over the 4-month interval. With short intervals of focused training, error rates in force delivery were reduced by 23% to 45%, depending on target. Within-subject variability was 1/3 to 1/2 that of between-subject variability. Load increases were directly related to rate of loading.

The findings of this study show that recalibration of spinal manipulation performance of experienced clinicians toward arbitrary target values in the thoracic spine is feasible. This study found that experienced clinicians are internally consistent in performance of procedures under standardized conditions and that focused training may help clinicians learn to modulate procedure characteristics.