Descent, eccentricCentre of mass inside base of support
Side view
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Split squat

Feet on hip-width tracks, rear heel up, 16 kg dumbbell in each hand. The pelvis descends almost vertically; each knee is placed by 3D IK from its own foot.

-25°Ankle dorsiflexion
5°Knee flexion
36°Hip flexion
5°Trunk from vertical
7°Arm to trunk
0°Elbow flexion
21Ankle spacing, cm
44Hand spacing, cm
-1Knee outside ankle, cm
–Knee cave, ° inside toe line
49 / 51Load left / right, %
0Pelvis drop, cm

Load and joint demand

Load in the model: 16 kg each hand. Balance and joint demand re-solve as you change it.

Lower back
33 / 33
Hip extensors
19 / 19
Knee extensors
18 / 93
Calves
25 / 26

N·m now / peak over the rep.

Faults

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.

Body

Femur changes keep standing height fixed by shortening or lengthening the torso. Longer femurs force more forward lean in any squat.

Muscles worked

Quads
100 pts
Glutes
100 pts
Abs and core
25 pts

Effort and your quota

6.5/10 effort6.8fatigue per set

Your quota per set: 10 reps at 16 kg each hand, stopping 2 reps short of failure.

One hard set earns 200 legs points, 25 core points.

Prime movers

Quadriceps and gluteus maximus of the front leg; rear-leg hip flexors are stretched.

What to look for

  • Front shin approaches vertical at the bottom when the stance is long enough.
  • Rear knee drops straight down toward the floor.
How the model works, and its limits

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.