EFFECT OF YOGA INTERVENTION ON POSTERIOR-CHAIN FLEXIBILITY IN CORPORATE EMPLOYEES: A V-SIT-AND-REACH ANALYSIS BY GENDER AND AGE GROUP

Abstract

Background: Flexibility of the hamstring muscles and lumbar spine is a critical component of musculoskeletal health in desk-based corporate workers, where prolonged sedentary postures contribute to posterior chain tightness and increased risk of low back pain. Yoga is widely practised for improving flexibility; however, evidence examining yoga’s effects on posterior-chain flexibility in corporate employees, with subgroup analysis by gender and age, is limited. Objective: To evaluate the effect of a 12-week yoga-based intervention on posterior-chain flexibility, as measured by the V Sit and Reach Test (VSRT), in corporate employees, and to examine whether intervention effects differ by gender and age group. Methods: A single-group, pre-test–post-test intervention study was conducted with 114 corporate employees (67 male, 47 female) from Ahmedabad, Gujarat, India. Participants received a 12-week structured yoga intervention (5 sessions/week, 60 minutes/session) using the S-VYASA Integrated Yoga Therapy Module for Chronic Low Back Pain (Nagendra & Nagarathna, 2010), delivered under the supervision of a qualified yoga instructor. The V Sit and Reach Test (VSRT) was administered at pre-test (T1) and post-test (T2) to assess flexibility in inches. Within-group paired-samples t-tests were conducted for the total sample, for two gender subgroups, and for three age subgroups (25–34, 35–44, 45 and above) using SPSS Paired-Samples T-Test (α = .05, two-tailed). Results: The total sample demonstrated a statistically significant improvement in VSRT scores from pre-test (M = 14.92 inches, SD = 2.36) to post-test (M = 15.03 inches, SD = 2.26; t(113) = 3.646, p < 0.01, Cohen’s d = 0.34). By gender, male participants showed a statistically significant improvement (n = 67, t(66) = 3.200, p = 0.002, d = 0.39), while female participants showed a smaller, non-significant trend (n = 47, t(46) = 1.771, p = 0.083, d = 0.26); female participants had higher baseline flexibility than males (Pre M = 15.60 vs. 14.45 inches). By age group, the 25–34 subgroup showed a statistically significant improvement (n = 68, t(67) = 2.546, p = 0.013, d = 0.31), while the 35–44 subgroup (n = 32, t(31) = 1.791, p = 0.083, d = 0.32) and the 45-and-above subgroup (n = 14, t(13) = 1.883, p = 0.082, d = 0.50) showed meaningful but statistically non-significant trends, likely reflecting smaller subgroup sample sizes. Flexibility rating category analysis showed a net upward shift, with the Very Poor category decreasing from 8 to 7 participants and the Poor category decreasing from 23 to 21, alongside a corresponding increase in the Below Average category (36 to 39). Conclusion: A 12-week yoga-based intervention is associated with a statistically significant improvement in posterior-chain flexibility in corporate employees, with the clearest effects observed among male participants and in the 25–34 age subgroup, and a promising but underpowered trend among female participants and in the 45-and-above age subgroup. As this was a single-group, pre-post design without a concurrent control group, the improvement cannot be definitively attributed to the intervention alone; temporal or practice effects cannot be ruled out. These findings nonetheless support further controlled investigation of S-VYASA Integrated Yoga Therapy Module for Chronic Low Back Pain, particularly posterior chain stretching sequences, in corporate occupational health programmes.