Effect of yoga on balance, falls, and bone metabolism: a systematic review of randomized controlled trials in healthy individuals.

This systematic review of 18 RCTs assessed the impact of yoga on balance, fall risk, fear of falling, bone mineral density (BMD), and bone turnover markers in healthy individuals. Yoga significantly improved balance but its effects on BMD were inconclusive. Standardised protocols and longer-term studies are needed.

Background: Yoga's effects on interconnected bone health parameters viz balance, falls, fear of falling (FOF), bone mineral density (BMD), and bone turnover markers (BTMs) in healthy individuals are unclear. We critically evaluated randomized controlled trials (RCTs) that compared yoga to no intervention control (NIC) or comparators such as Tai Chi, on these parameters in healthy individuals.

Methods: We systematically searched multiple scientific data bases using a predefined protocol. We summarized data qualitatively when there was heterogeneity in reporting. A meta-analysis of those studies comparing yoga to NIC was done. Since the included studies used different scales for the same outcomes, we used standardised mean differences (SMDs) to allow pooling. We assessed the risk of bias with the Cochrane RoB2 tool for randomized trials and graded certainty of evidence using the GRADE approach.

Results: Eighteen RCTs with 1408 participants were evaluated. Fifteen explored yoga's effects on balance and/or falls or FOF, and three RCTs, its effect on BMD and BTMs. Yoga types included Hatha, Vinyasa, Ashtanga, Iyengar, Bikram, and specially designed yoga protocols. Twenty-four kinds of balance assessment tools were used in the studies. Study durations varied from 6 weeks to 14 months. Almost all the studies reported positive effects of yoga on balance compared to NIC, and non-inferiority when compared to active interventions such as Tai Chi. Meta-analysis of four RCTs comparing yoga to NIC demonstrated significant improvements in static balance with yoga (SMD = 2.36; 95% CI 1.13-3.58; P = 0.0002, I² = 93% ⊕ ⊕ ⊝ ⊝). Yoga's effects on falls and FOF were mixed. Two studies showed a positive effect of yoga on bone formation. Yoga was found to have a positive effect on BMD in only one study. Meta-analysis of two RCTs showed no significant effect on BMD for yoga compared to NIC. The studies exhibited substantial heterogeneity in terms of yoga styles, intervention durations, and assessment methods.

Conclusion: In healthy adults, low certainty evidence shows that yoga has a beneficial effect on balance. Its effect on BMD remains unclear. Standardised protocols and longer-term research are necessary to facilitate more definitive conclusions on yoga's role in enhancing skeletal health and preventing falls.