Urdhva Prasarita Eka Padasana
hold 20 s each side · intermediate · move in slowly, hold, come out the same way
Take care: The head is below the heart: skip it with high blood pressure, a heart condition or glaucoma, and with a recent hamstring strain.
Urdhva Prasarita Eka Padasana. From a standing forward fold on the right leg, the trunk hangs down toward the standing shin while the straight left leg lifts high behind; the hands rest on the mat a little in front of the standing foot (on blocks if the floor is far). The hips stay square; the centre of mass is solved over the standing foot.
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: 57 legs points, 12 core points.
Hamstrings of the standing leg (stretched), gluteus maximus and hamstrings of the lifted leg, hip flexors of the lifted leg (stretched), spinal erectors (stretched), foot and ankle stabilisers.
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.