Effect of Exercise and Custom-Made Flexible Orthotics on Blood Pressure and Heart Rate Variability
John Zhang, MD., Ph.D.,Logan College of Chiropractic, and William M. Austin, D.C., Foot Levelers, Inc.
The hypothesis for the study was that exercise and custom-made orthotics have a positive impact on the heart rate variability (HRV) and blood pressure(BP). The null hypothesis was that exercise and custom-made flexible orthotics would not induce positive changes in HRV and BP during the study period.
This study was reviewed and approved by the Institutional Review Board of Logan College of Chiropractic. All subjects were randomized into control and experimental groups by a randomization table. Both groups had the same exercise program and only the experimental group wore custom-made flexible orthotics. The exercise effects were compared before and after the training. Each subject must be a Ping-Pong club member for the last 5 years and be an active member in the club. The subject must also play no less than twice a week or no less than 6 hours a week. Heart rate variability was measured using Biocom's Heart Rhythm Scanner for HRV data collection. Blood pressure was determined by using Biopac blood pressure measurement equipment. Foot Leveler's custom-made flexible orthotics were factory-fitted to tennis shoes for the study.The study lasted 5 months with one data collection per month except for the 4th month. The baseline HRV and BP were recorded before the warm-up period. When one player had played with two other players in a non stop fashion, the data were collected again immediately after the second game. No rest was allowed for this data collection in order to detect the peak heart rate and blood pressure changes. The third data collection of HRV andBP was at the end of the playing period.