Biomechanical Characteristics of the Modified Downward Facing Dog Yoga Pose in Healthy Older Adults

Abstract

Increasingly, yoga is being promoted as a safe and effective exercise program for older adults. The Downward Facing Dog (DFD) is one of the most common yoga poses, classically practiced with the hands placed on the floor. However, for older practitioners, the pose is often modified (mDFD) by having the hands placed on a wall or the back of a chair in order to make it more accessible, and potentially safer; this study focused on the wall method. In view of the absence of published data on the biomechanical profile of the mDFD, it is important to characterize these variables to help determine the physical demands of this yoga pose. This will lead to the development of balanced, safe and effective yoga programs for older adults. PURPOSE: To determine the kinematic and kinetic characteristics of the mDFD pose in healthy older adults. METHODS: 24 subjects (70.8 yrs ±4.2) performed the mDFD under a qualified yoga instructor's guidance. Sagittal plane kinetic and kinematic data were obtained in the position of maximal forward bending, using instrumented force platforms and an 11-camera motion capture system (60 Hz). Net joint moments were derived through standard inverse dynamic calculations. Flexion angles and flexor moments are reported as positive. RESULTS: In the sagittal plane, mean dominant limb joint angles were: ankle= 12.6 ±6.4°, knee= 26.2 ±13.5°, hip= 83.1 ±17.6°, shoulder= 118.8 ±13.6°, elbow= 48.8 ±15.6°, and wrist= -15.5 ±12.3°. The angle of trunk relative to pelvis was -9.0 ±11.3°, and head relative to trunk was 17.4 ±12.6°. Mean internal moments of the dominant leg in the sagittal plane were: ankle= -0.32 ±0.13N.m/kg (plantar-flexor), knee= 0.02 ±0.19 N.m/kg, and hip= -0.48 ±0.20 N.m/kg. The moment at the trunk was -43.90 ±17.24 N.m/kg. CONCLUSION: The largest joint excursion occurs at the shoulder. This is an important consideration for older adults with reduced shoulder range of motion. The biomechanical demands of the mDFD were primarily on the trunk extensors, hip extensors, knee flexors and ankle plantar-flexors. The plantar-flexor and extensor moments at the ankle and hip are the major contributors to the support moment. These data may be used to inform selection and modification of the mDFD pose to suit older adults with different musculoskeletal constraints and pathologies. Supported by NIH Grant ROI -AT004869-01