The relation between the application angle of spinal manipulative therapy (SMT) and resultant vertebral accelerations in an in situ porcine model
ABSTRACT It has been hypothesized that the posterior tissues of the spine are frictionless and therefore allow only the normal force component of spinal manipulative therapy (SMT) to pass to underlying vertebrae. Given this assumption, vertebrae could not be moved in practitioner-defined directions by altering the application angle of SMT. To investigate this possibility, porcine lumbar spines were excised and then SMT applied at 90 degrees to the posterior tissues of the target vertebra. A standard curve was constructed of increasing SMT force versus vertebral acceleration. SMT forces were then applied at 60 degrees and 120 degrees and the resulting accelerations substituted into the standard curve to obtain the transmitted force. Results showed that vertebral accelerations were greatest at a 90 degrees SMT application angle and decreased in all axes at application angles not equa l90 degrees . The average decrease in transmitted force using application angles of 60 degrees and 120 degrees was within 5% of the predicted absolute value. In this model, SMT applied at a non-normal angle does not increase vertebral acceleration in that same direction, but acts to reduce transmitted force. This work provides justification for future studies in less available human cadavers. It is not yet known if variations in SMT application angle have relevance to clinical outcomes or patient safety.
- Free Radical Biology and Medicine 01/2010; 49. DOI:10.1016/j.freeradbiomed.2010.10.413 · 5.71 Impact Factor
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ABSTRACT: Like other factors that can influence treatment efficacy (eg, dosage, frequency, time of day), the site of treatment application is known to affect various physical interventions such as topical anesthetics and cardiopulmonary resuscitation. Like these examples, spinal manipulative therapy (SMT) is a physical intervention that may exhibit maximal benefit when directed to a specific site. Whereas numerous studies of SMT efficacy have produced mixed results, few studies have taken into account the site of SMT application.The spine journal: official journal of the North American Spine Society 10/2013; 15(6). DOI:10.1016/j.spinee.2013.07.480 · 2.80 Impact Factor
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ABSTRACT: The purpose of this study was to systematically review studies that quantify the high-velocity, low-amplitude (HVLA) spinal thrust, to qualitatively compare the apparatus used and the force-time profiles generated, and to critically appraise studies involving the quantification of thrust as an augmented feedback tool in psychomotor learning. A search of the literature was conducted to identify the sources that reported quantification of the HVLA spinal thrust. MEDLINE-OVID (1966-present), MANTIS-OVID (1950-present), and CINAHL-EBSCO host (1981-present) were searched. Eligibility criteria included that thrust subjects were human, animal, or manikin and that the thrust type was a hand-delivered HVLA spinal thrust. Data recorded were single force, force-time, or displacement-time histories. Publications were in English language and after 1980. The relatively small number of studies, combined with the diversity of method and data interpretation, did not enable meta-analysis. Twenty-seven studies met eligibility criteria: 17 studies measured thrust as a primary outcome (13 human, 2 cadaver, and 2 porcine). Ten studies demonstrated changes in psychomotor learning related to quantified thrust data on human, manikin, or other device. Quantifiable parameters of the HVLA spinal thrust exist and have been described. There remain a number of variables in recording that prevent a standardized kinematic description of HVLA spinal manipulative therapy. Despite differences in data between studies, a relationship between preload, peak force, and thrust duration was evident. Psychomotor learning outcomes were enhanced by the application of thrust data as an augmented feedback tool.Journal of manipulative and physiological therapeutics 09/2010; 33(7):542-53. DOI:10.1016/j.jmpt.2010.08.001 · 1.25 Impact Factor