Hip circles
3 reps · advanced
Take care: Skip it with wrist or shoulder pain or a weak lower back (lean on the forearms or keep the knees bent to make it easier), and during pregnancy.
Sitting and leaning back about 45° on straight arms, the hands on the mat behind the hips, the straight legs lift together into a V. The legs draw a circle with the toes: to the right, down, round to the left and back up, then the other way, the trunk and the hands 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.
3 slow, controlled reps. Pilates is practised for control, balance and mobility, never to failure, so this does not change with your limits.
Level: advanced. One round counts like light conditioning work: 12 legs points, 12 push points, 12 pull points, 12 arms points, 35 core points.
Rectus abdominis, obliques, transversus abdominis, hip flexors (iliopsoas, rectus femoris), triceps and posterior deltoid (supporting on the hands).
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.