Effect of a long-term modified Tai Chi-based intervention in attenuating bone mineral density in postmenopausal women in southeast China: study protocol for a randomized controlled trial

Background and objectives: According to Chinese White Paper on Osteoporosis Prevention (2009), an estimated number of 69 million Chinese people are experiencing osteoporosis caused by loss and deterioration of bone mineral density (BMD). Middle-aged women have a greater possibility in developing osteoporosis in comparison with men because of a decreased estrogen level and degeneration in physical fitness level. A Tai Chi-based intervention in the present study will be created based on four components consisting of fall-prevention/balance training, stretching/flexibility training, resistance training (Tai Chi push hand), and strength training.Design: A prospective three-arm parallel randomized controlled trial.Methods: This study will take place in ten community centers in southeast China, and postmenopausal women aged 50–65 years and without menses for 6–12 months will be recruited and randomly assigned into three groups with the allocation ratio of 1:1:1 (n = 50 for each group), including two experimental groups (a traditional Tai Chi group and a modified Tai Chi-based intervention group) and a control group. Participants in the control group will be asked to maintain their original lifestyle during the 12-month intervention period. Participants in the traditional Tai Chi and modified Tai Chi-based intervention groups will experience the traditional Yang-style Tai Chi and receive the modified Tai Chi-based intervention, respectively. The modified Tai Chi-based intervention contains four components: 1) eight Tai Chi based fall-prevention movements; 2) ten Qigong-based stretching/flexibility movements; 3) eight resistance training-based Tai Chi push hand movements; 4) eight Chen style-based Tai Chi movements. For both the experimental groups, study participants will experience four 60-minute Tai Chi training sessions weekly for 12 months.Outcome measures: BMD at multiple musculoskeletal regions is primary outcome measure. Secondary outcome measures include low limb muscle strength, physical function, and reaction time at both upper and low limbs, which will be measured at baseline and 12 months (at the end of the intervention).Discussion: Results of this study will provide preliminary evidence regarding the value of Tai Chi movement as an intervention for attenuating BMD loss in postmenopausal women.Ethics and dissemination: This study protocol was approved by the Institution Review Board of Shanghai Sports University (approval No. 11290502800) and will be performed in accordance with the principles of the Declaration of Helsinki. Patient recruitment started in August 2017. The analysis of primary outcome measures will be completed in October 2018. The estimated study completion date is June 2019. Dissemination plans include presentations at scientific conferences and scientific publications.Trial registration: This trial was registered with the Chinese Clinical Trial Registry (registration No. ChiCTR-IOR-15005887) on 27 January 2015.