8 reps each side · beginner
Take care: Rest the head on the mat if the neck strains; skip it during pregnancy and after giving birth until the abdominals have recovered.
The first of the Series of Five: lying on the back with the head and shoulders curled up about 30°, one knee draws in toward the chest, the outside hand on its ankle and the inside hand just below its knee, while the other leg reaches long at about 40° off the mat. The legs switch and the hands follow, the trunk staying still.
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.
8 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: beginner. One round counts like light conditioning work: 25 legs points, 29 core points.
Rectus abdominis (holding the curl), transversus abdominis, obliques, hip flexors; hamstrings and gluteus maximus of the leg reaching long.
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.