4 reps each side · intermediate
Take care: Do the mermaid side plank, on the bottom knee, until the wrist and shoulder are strong enough; skip it with a shoulder or wrist injury.
The classical side bend. Sitting on the right hip with the legs straight and the feet together, the top foot a little in front, the right hand on the mat out from the hip with the arm straight and the top arm resting along the body. The hips lift until the body arches up in a rainbow from the feet to the head, the top arm sweeping overhead; then the hips lower to hover over the mat as the trunk rises and the top arm returns along the body. The supporting arm stays straight and the hand 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.
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: 41 legs points, 35 push points, 16 pull points, 12 arms points, 70 core points.
Obliques and quadratus lumborum (lifting the hips), gluteus medius, serratus anterior, deltoids and rotator cuff (the supporting shoulder), triceps, adductors (pressing the feet together); the top side of the waist 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.