Parivrtta Trikonasana
hold 20 s each side · intermediate · move in slowly, hold, come out the same way
Take care: Twist gently and keep the spine long; skip it with a disc problem, a sacroiliac complaint or a recent back injury.
Parivrtta Trikonasana. A shorter stance along the mat, hips facing forward, front (right) foot forward and back foot turned out about 45°, both legs straight. The trunk folds forward over the front leg until it is about level, then turns to the right: the left fingertips come to the mat (or a block) outside the front foot and the right arm reaches straight up, the chest opening toward the right. The hips stay square (solved 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: 18 legs points, 8 push points, 57 core points.
Obliques and spinal rotators, hamstrings and gluteus medius of the front leg (stretched), spinal erectors, deltoids (holding the arm).
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.