Effects of a Beginning Judo Class on Heart Rate

We evaluated the heart rate responses of 15 adult and six child subjects to beginning judo class sessions. Heart rate responses were compared to cardiovascular intensity ranges recommended by the American College of Sports Medicine (ACSM). Heart rate responses of adults (n=15) averaged 70 percent of age-predicted maximum heart rate with a range of 96 beats/minute to 154 beats/minute. The heart rate responses of the children (n=6) averaged 68 percent of age-predicted maximum heart rate with a range of 133-161 beats/min. Our results show that judo is effective in elevating heart rate to levels recommended by the ACSM for appropriate periods of time to improve cardiovascular fitness.

A Measurement System Experiment to Evaluate the Nosing-to-nosing Method for Measuring Dimensions of Steps

Non-uniformity of steps within a flight is a major risk factor for falls. Guidelines and requirements for uniformity of step risers and tread depths assume the measurement system provides precise dimensional values. The state-of-the-art measurement system is a relatively new method, known as the nosing-to-nosing method. It involves measuring the distance between the noses of adjacent steps and the angle formed with the horizontal. From these measurements, the effective riser height and tread depth are calculated. This study was undertaken for the purpose of evaluating the measurement system to determine how much of total measurement variability comes from the step variations versus that due to repeatability and reproducibility (R&R) associated with the measurers. Using an experimental design quality control professionals call a measurement system experiment, two measurers measured all steps in six randomly selected flights, and repeated the process on a subsequent day. After marking each step in a flight in three lateral places (left, center, and right), the measurers took their measurement. This process yielded 774 values of riser height and 672 values of tread depth. Results of applying the Gage R&R ANOVA procedure in Minitab software indicated that the R&R contribution to riser height variability was 1.42%; and to tread depth was 0.50%. All remaining variability was attributed to actual step-to-step differences. These results may be compared with guidelines used in the automobile industry for measurement systems that consider R&R less than 1% as an acceptable measurement system; and R&R between 1% and 9% as acceptable depending on the application, the cost of the measuring device, cost of repair, or other factors.