Supplementary file 1_Validation of Taijiquan (Tai Chi) Exercise Commitment Scale for Chinese Elderly (TECS-CE).pdf

Thirty participants completed the scale twice with a 3-week interval to examine test–retest reliability. Content validity was evaluated by five experts using the Index of Item–Objective Congruence (IOC). Construct validity was examined using EFA and CFA, while criterion-related validity was examined through correlations and regression analyses with self-reported Taijiquan exercise behavior.</p>Results<p>The final TECS-CE contained 33 items representing two commitment dimensions—Want to Commit and Have to Commit—and six determinants: Satisfaction, Social Constraints, Involvement Alternatives, Personal Investment, Social Support, and Involvement Opportunities.

The two commitment dimensions explained 65.005% of the variance, while the six determinants explained 75.378%. CFA indicated acceptable model fit for the reported models; for the structural model, χ²/df = 1.371, RMSEA = 0.039, RMR = 0.072, AGFI = 0.882, GFI = 0.903, NNFI = 0.984, and CFI = 0.986. Composite reliability ranged from 0.91 to 0.94 and AVE ranged from 0.68 to 0.71.

Cronbach’s alpha coefficients ranged from 0.932 to 0.984, and test–retest coefficients ranged from 0.824 to 0.938. The TECS-CE dimensions and determinants were significantly associated with self-reported exercise behavior.</p>Conclusion<p>The findings provide evidence that the TECS-CE has acceptable content, construct, criterion-related, and reliability evidence for assessing Taijiquan exercise commitment among the older adults included in this study.

Because the study was cross-sectional and used convenience sampling and self-reported exercise behavior, longitudinal and multisite studies are needed to establish predictive validity and broader generalizability.</p>