Parivrtta Utkatasana
hold 20 s each side · intermediate · move in slowly, hold, come out the same way
Take care: Sit less deep if the knees hurt; twist gently and skip it with a disc problem or a recent back injury.
Parivrtta Utkatasana (twisted chair). Feet together, the knees bend to about 75° and the hips sit back as in chair; the palms press together at the heart, the trunk leans forward about 45° and turns to the right until the left upper arm comes to the outside of the right thigh, the thumbs at the sternum. The knees stay level with each other; the hips are solved so the centre of mass stays over the feet.
Bodyweight: no weights. Joint demand below is your own body's weight in this position.
Faults grow with knee bend and apply to lifts standing on the floor. The fault check flags a knee caving more than 10° inside the line of the toes and a load split beyond 60/40. Knee cave shows best in the front camera.
Femur changes keep standing height fixed by shortening or lengthening the torso. Longer femurs force more forward lean in any squat.
Hold for 20 seconds on each side: move into the pose slowly, breathe steadily, and come out the way you went in. Yoga is practised for control, balance and mobility, never to failure, so this does not change with your limits.
Level: intermediate. One round counts like light conditioning work: 72 legs points, 12 push points, 35 core points.
Quadriceps, gluteus maximus, obliques and spinal rotators, adductors (keeping the knees level), spinal erectors, pectoralis major (pressing the palms).
One 3D skeleton drives both views. Segment lengths and widths are Winter's anthropometric ratios of height; segment masses and centre-of-mass positions follow Dempster's data. For free-standing lifts the whole-body angle is found numerically so the combined centre of mass of lifter and load sits over the middle of the foot. Arms and legs use two-link inverse kinematics with a pole direction. Rep timing follows a minimum-jerk profile.
Balance is quasi-static, so ballistic lifts are shown slowed down. Cable pull and pad support forces are not modelled. The spine is one rigid segment and joints have no range-of-motion limits or muscle forces.