The biomechanical demands of standing yoga poses in seniors: The Yoga empowers seniors study (YESS).

BACKGROUND: The number of older adults participating in yoga has increased dramatically in recent years; yet, the physical demands associated with yoga performance have not been reported. The primary aim of the Yoga Empowers Seniors Study (YESS) was to use biomechanical methods to quantify the physical demands associated with the performance of 7 commonly-practiced standing yoga poses in older adults. METHODS: 20 ambulatory older adults (70.7+-3.8 yrs) attended 2 weekly 60-minute Hatha yoga classes for 32 weeks. The lower-extremity net joint moments of force (JMOFs), were obtained during the performance of the following poses: Chair, Wall Plank, Tree, Warrior II, Side Stretch, Crescent, and One-Legged Balance. Repeated-measure ANOVA and Tukey's post-hoc tests were used to identify differences in JMOFs among the poses. Electromyographic analysis was used to support the JMOF findings. RESULTS: There was a significant main effect for pose, at the ankle, knee and hip, in the frontal and sagittal planes (p=0.00-0.03). The Crescent, Chair, Warrior II, and One-legged Balance poses generated the greatest average support moments. Side Stretch generated the greatest average hip extensor and knee flexor JMOFs. Crescent placed the highest demands on the hip flexors and knee extensors. All of the poses produced ankle plantar-flexor JMOFs. In the frontal plane, the Tree generated the greatest average hip and knee abductor JMOFs; whereas Warrior II generated the greatest average hip and knee adductor JMOFs. Warrior II and One-legged Balance induced the largest average ankle evertor and invertor JMOFs, respectively. The electromyographic findings were consistent with the JMOF results. CONCLUSIONS: Musculoskeletal demand varied significantly across the different poses. These findings may be used to guide the design of evidence-based yoga interventions that address individual-specific training and rehabilitation goals in seniors. CLINICAL TRIAL REGISTRATION: This study is registered with NIH Clinicaltrials.gov #NCT 01411059.

The physical demands of the tree (vriksasana) and one-leg balance (utthita hasta padangusthasana) poses performed by seniors: a biomechanical examination.

Yoga is considered especially suitable for seniors because poses can be modified to accommodate practitioners' capabilities and limitations. In this study, biomechanical assessments on healthy seniors (n = 20; 70.1 ± 3.8 yr) were used to quantify the physical demands, (net joint moments of force [JMOFs] and muscular activation in the lower extremities) associated with the performance of 3 variations (introductory, intermediate, advanced) of 2 classical Hatha yoga poses - Tree and One-Leg Balance (OLB). ANOVA and Cohen's-d were used to contrast the postural variations statistically. The advanced (single-limb, without additional support) versions were hypothesized to generate the greatest demands, followed by the intermediate (single-limb [Tree] and bilateral-limb [OLB] with support) and introductory (bilateral-limb) versions. Our findings, however, suggest that common, long-held conceptions about pose modifications can be counter-intuitive. There was no difference between the intermediate and advanced Tree variations regarding hip and knee JMOFs in both the sagittal and frontal planes (P = 0.13-0.98). Similarly, OLB introductory and intermediate variations induced sagittal JMOFs that were in the opposite direction of the classic advanced pose version at the hip and knee (P < .001; d = 0.98-2.36). These biomechanical insights provide evidence that may be used by instructors, clinicians and therapists when selecting pose modifications for their yoga participants.

Yoga Improves Upper-Extremity Function and Scapular Posturing in Persons with Hyperkyphosis.

OBJECTIVE: Hyperkyphosis (excess thoracic spine curvature) is associated with upper-extremity functional limitations and altered scapular posturing. The purpose of this study was to quantify the changes in upper-extremity function and scapular posturing following a 6-month yogaintervention in persons with hyperkyphosis. METHODS: Twenty-one older adults with hyperkyphosis (75.5+7.4 yrs) enrolled in the UCLA Yoga for Kyphosis randomized controlled trial, elected to participate in this uncontrolled, prepost substudy of upper-extremity function. They were measured at baseline and after a 24-week yoga intervention. Maximum vertical reach and timed book tests were used to evaluate upper-extremity function. Scapular posturing was quantified using a motion analysis system and data was obtained under 4 conditions: 1) quiet-standing, 2) normal walking, 3) fast walking, and 4) seated. Paired t-tests were used to test for changes between baseline and 6-month follow-up measures and Cohen's d was calculated to examine effect sizes. RESULTS: Following the 6-month yoga intervention, participants improved their book test performance by 26.4% (p < 0.001; d = 1.5). Scapular protraction decreased by 2.9% during the static-sitting condition (p < 0.001; d = 0.5) and the overall excursion of the scapulae decreased for both fast (25.0%, p < 0.05; d = 0.6) and self-selected walking (29.4%, p < 0.01; d = 0.9). There were no changes in maximum vertical reach. CONCLUSION: Subjects demonstrated significant improvements with small to large effect sizes in the timed book test and scapular posturing to a less protracted position during both static and dynamic conditions after the intervention. These adaptations are likely to reduce the risk of scapular impingement and help preserve functional independence in older adults.

Yoga Empowers Seniors Study (YESS): Design and Asana Series.

The practice of yoga asanas (postures) may be an optimal method of preserving or enhancing physical function in older men and women. However, the physical demands, efficacy and safety of an asana practice for seniors have not been well studied. The Yoga Empowers Seniors Study (YESS) is an intervention development study that created two senior-adapted series of asanas targeted for an ambulatory older population. YESS is using biomechanics and physical performance tests to acquire information about the physical demands placed on the muscles and joints by the asanas and the functional performance adaptations resulting from the yoga practice. This manuscript details the standardized, senior-adapted, YESS asana series and the additional asana modifications provided when participants had physical limitations. This presentation will enable the yoga research and teaching communities to interpret the biomechanics, physical performance and side effects outcomes of YESS.