Ashta Chandrasana
hold 30 s each side · beginner · move in slowly, hold, come out the same way
Take care: Lower the back knee to the mat (low lunge) if balance or the front knee is a problem.
Ashta Chandrasana (crescent lunge). A long stance along the mat with the feet hip-width apart: the front (right) knee bends to about 90° over the ankle, the back leg is straight and strong with the heel lifted, on the ball of the foot. The hips face forward, the trunk rises upright and the arms reach overhead. The front foot carries about 65% of the weight; the pelvis is solved for the 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: 86 legs points, 8 push points, 12 core points.
Quadriceps and gluteus maximus of the front leg, hip flexors of the back leg (stretched), calves, deltoids (holding the arms up), 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.