Spinal manipulation is a manual treatment technique that delivers a thrust,using specific biomechanical parameters to exert its therapeutic effects.These parameters have been shown to have a unique dose-response relat...Spinal manipulation is a manual treatment technique that delivers a thrust,using specific biomechanical parameters to exert its therapeutic effects.These parameters have been shown to have a unique dose-response relationship with the physiological responses of the therapy.So far,however,there has not been a unified approach to standardize these biomechanical characteristics.In fact,it is still undetermined how they affect the observed clinical outcomes of spinal manipulation.This study,therefore,reviewed the current body of literature to explore these dosage parameters and evaluate their significance,with respect to physiological and clinical outcomes.From the experimental studies reviewed herein,it is evident that the modulation of manipulation’s biomechanical parameters elicits transient physiological responses,including changes in neuronal activity,electromyographic responses,spinal stiffness,muscle spindle responses,paraspinal muscle activity,vertebral displacement,and segmental and intersegmental acceleration responses.However,to date,there have been few clinical trials that tested the therapeutic relevance of these changes.In addition,there were some inherent limitations in both human and animal models due to the use of mechanical devices to apply the thrust.Future studies evaluating the effects of varying biomechanical parameters of spinal manipulation should include clinicians to deliver the therapy in order to explore the true clinical significance of the dose-response relationship.展开更多
By using an instrumented impact pendulum, the force versus time curves of 7075-T651 aluminum welds were obtained from standard Charpy-V samples. Considering the force-time curves and constant impact velocity, the frac...By using an instrumented impact pendulum, the force versus time curves of 7075-T651 aluminum welds were obtained from standard Charpy-V samples. Considering the force-time curves and constant impact velocity, the fracture energies for different zones were quantified. A fracture energy improvement for the HAZ(33.6 J) was observed in comparison with the weld metal(7.88 J), and base metal(5.37 J and 7.37 J for longitudinal and transverse directions, respectively). This toughness increment was attributed to the microstructural transformation caused by the thermodynamic instability of η′ precipitates during the welding. Fracture energy for weld metal was higher than that for base metal, probably due to pores created during solidification. Regarding the dynamic yielding force obtained from the force-time curves, an approximation to the dynamic yield strength for weld, HAZ and base metal was determined. Fracture surfaces revealed an intergranular failure for base metal in longitudinal direction, whereas a predominately brittle failure(cleavage) with some insights of ductile characteristics was observed for the transverse direction. In contrast, a ductile failure was observed for weld metal and HAZ.展开更多
文摘Spinal manipulation is a manual treatment technique that delivers a thrust,using specific biomechanical parameters to exert its therapeutic effects.These parameters have been shown to have a unique dose-response relationship with the physiological responses of the therapy.So far,however,there has not been a unified approach to standardize these biomechanical characteristics.In fact,it is still undetermined how they affect the observed clinical outcomes of spinal manipulation.This study,therefore,reviewed the current body of literature to explore these dosage parameters and evaluate their significance,with respect to physiological and clinical outcomes.From the experimental studies reviewed herein,it is evident that the modulation of manipulation’s biomechanical parameters elicits transient physiological responses,including changes in neuronal activity,electromyographic responses,spinal stiffness,muscle spindle responses,paraspinal muscle activity,vertebral displacement,and segmental and intersegmental acceleration responses.However,to date,there have been few clinical trials that tested the therapeutic relevance of these changes.In addition,there were some inherent limitations in both human and animal models due to the use of mechanical devices to apply the thrust.Future studies evaluating the effects of varying biomechanical parameters of spinal manipulation should include clinicians to deliver the therapy in order to explore the true clinical significance of the dose-response relationship.
基金CONACy T (project CB 177834)SIP-IPN for the funds given to conduct this research
文摘By using an instrumented impact pendulum, the force versus time curves of 7075-T651 aluminum welds were obtained from standard Charpy-V samples. Considering the force-time curves and constant impact velocity, the fracture energies for different zones were quantified. A fracture energy improvement for the HAZ(33.6 J) was observed in comparison with the weld metal(7.88 J), and base metal(5.37 J and 7.37 J for longitudinal and transverse directions, respectively). This toughness increment was attributed to the microstructural transformation caused by the thermodynamic instability of η′ precipitates during the welding. Fracture energy for weld metal was higher than that for base metal, probably due to pores created during solidification. Regarding the dynamic yielding force obtained from the force-time curves, an approximation to the dynamic yield strength for weld, HAZ and base metal was determined. Fracture surfaces revealed an intergranular failure for base metal in longitudinal direction, whereas a predominately brittle failure(cleavage) with some insights of ductile characteristics was observed for the transverse direction. In contrast, a ductile failure was observed for weld metal and HAZ.
