This study quantitatively assessed the mechanical reliability and validity of position, torque and velocity measurements of the Biodex System 3 isokinetic dynamometer. Trial-to-trial and day-to-day reliability were assessed during three trials on two separate days. To assess instrument validity, measurement of each variable using the Biodex System 3 dynamometer was compared to a criterion measure of position, torque and velocity. Position was assessed at 5 degrees increments across the available range of motion of the dynamometer. Torque measures were assessed isometrically by hanging six different calibrated weights from the lever arm. Velocity was assessed (30 degrees/s to 500 degrees/s) across a 70 degrees arc of motion by manually accelerating the weighted lever arm. With the exception of a systematic decrease in velocity at speeds of 300 degrees/s and higher, the Biodex System 3 performed with acceptable mechanical reliability and validity on all variables tested.
The purpose of this study was to compare isokinetic strength and flexibility measures between hamstring injured and noninjured athletes. Sixteen university athletes with history of hamstring injury were matched by motor dominance, sport, and position to sixteen university athletes without history of hamstring injury. Each subject was tested for concentric and eccentric quadriceps and hamstring peak torque and reciprocal muscle group ratios on a Kinetic Communicator(R) (KIN-COM) dynamometer at 60 degrees /sec and 180 degrees /sec. Each subject's hamstring flexibility was determined by passively extending the knee while the hip was maintained at 90 degrees of flexion. Analysis of variance indicated that the injured extremity was significantly less flexible than the noninjured extremity within the hamstring injured group, and the hamstring injured group was less flexible than the noninjured group. No significant strength differences existed between the hamstring injured and noninjured group on any isokinetic measure evaluated. The importance of assessing hamstring flexibility is emphasized. J Orthop Sports Phys Ther 1991;13(3):118-125.
These findings document effects of early childhood diarrhea on later school readiness and performance and hence potential long-term human and economic costs of ECD, which warrant further attention and far greater investment for the control of ECD and its consequences.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.