Descent, eccentric
Side view
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Belt squat

Standing on two platforms with 60 kg hanging from a hip belt between them; hands hold the rails, which carry balance, so there is no balance check. The load sits at the hips, so the spine carries none of it.

3°Ankle dorsiflexion
2°Knee flexion
9°Hip flexion
3°Trunk from vertical
31°Arm to trunk
91°Elbow flexion
44Ankle spacing, cm
60Hand spacing, cm
-7Knee outside ankle, cm
–Knee cave, ° inside toe line
–Load left / right, %
0Pelvis drop, cm

Load and joint demand

Load in the model: 60 kg. Balance and joint demand re-solve as you change it.

No gravity-based joint demand to show for this exercise.

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
82 pts
Adductors
64 pts

Effort and your quota

8/10 effort8.3fatigue per set

Your quota per set: 10 reps at 60 kg, stopping 2 reps short of failure.

One hard set earns 246 legs points.

Prime movers

Quadriceps, gluteus maximus, adductors.

What to look for

  • A way to load the legs heavily without loading the back.
  • Trunk stays upright because the weight hangs from the hips.
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.