4 reps each side · intermediate
Take care: Keep the chest lift small with a lower-back problem and skip the clasp if the shoulders are tight or injured; not during pregnancy.
Lying face down with one cheek on the mat, the hands clasped high on the back and the elbows dropped toward the mat. Both heels kick toward the seat three times, then the legs reach long and lift a little while the clasped hands reach back toward the feet and the chest lifts; then the chest lowers, the head turns to the other cheek and the hands return to the back.
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.
4 slow, controlled reps on each side. Pilates 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: 64 legs points, 7 push points, 16 pull points, 22 core points.
Hamstrings, gluteus maximus, spinal erectors, rhomboids and middle trapezius, posterior deltoid; pectoralis major and anterior deltoid stretched.
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.