Virabhadrasana I
hold 30 s each side · beginner · move in slowly, hold, come out the same way
Take care: Shorten the stance or ease the bend if the front knee hurts; skip it with a painful knee.
Virabhadrasana I. A long stance along the mat with the feet hip-width apart: the front (right) foot points forward, the back foot is turned out about 45° with its heel down. The front knee bends to about 90° over the ankle while the back leg stays straight; the hips face forward, the trunk is upright and the arms reach overhead, shoulder-width apart. The front foot carries about 60% of the weight; the pelvis is solved for the two knees and 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 30 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: beginner. One round counts like light conditioning work: 76 legs points, 11 push points, 28 core points.
Quadriceps and gluteus maximus of the front leg, hip flexors and calf of the back leg (stretched), deltoids (holding the arms up), spinal erectors, core.
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.