Trends in isodynamic and isometric trunk testing on the Isostation B200

A total of 200 men and 100 women with no prior history of low back pain were evaluated by a series of 6 different tests on the Isostation B200 (Isotechnologies, Hillsborough, NC, U.S.A.) to obtain normative data on the functional performance of the low back. The data collected in this descriptive study were analyzed for significant patterns and differences between an asymptomatic male and female population. In the range of motion test, male subjects demonstrated greater range of motion in all planes; however, values for women showed greater standard deviations. In the maximum isometric test, male torque values exceeded female values, but male values showed greater standard deviations. A rank order of parameter values was made from values recorded during repetitive tests for both men and women. Coupling patterns observed during single-plane repetitive tests allowed secondary and tertiary axes to be identified. Torque values generated over the set resistance were calculated for the repetitive tests conducted in three different planes. A positive curvilinear, concave downward relationship was observed when these values were plotted against the predetermined resistance settings. Future research will study the effect resistance settings on maximum torque output and the role of velocity as a key discriminator between normal and abnormal populations.