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Research Information
Subject: The Activator Adjusting Instrument - Biomechanical Title: Variability of Force Magnitude and Force Duration in Manual and Instrument-Based Manipulation Techniques Objective: The goal of this study was to compare the variation of manipulative forces produced by instruments and a manual technique. Methods: Four operators (2 experts and 2 novices) used 4 different mechanical instruments to apply force to a uniaxial load cell. A different group of 2 expert and 2 novice operators used a traditional manual technique to apply force to a sensor mat. Two primary outcome variables were obtained from each sensor system: peak-to-peak force magnitude (N) and peak-to-peak force duration (millisecond). Multiple analyses were performed to determine the absolute differences and variation in each variable. Results: Force-producing instrumentation exhibited less variation in absolute force and force duration compared to manual techniques. However, the same instrument in the hands of different operators often produced significantly different values of absolute force and force duration. Although absolute values of force magnitude generally differed between operators, intraoperator variation was equal for instruments and the manual technique. Conversely, for force duration, significant differences in interoperator variability were observed for the manual technique and for one of the instruments. Key Indexing Terms: Manipulation, Spinal; Reproducibility of Results; Instrument |