Lower and squatBalanced over midfoot
Side view
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Single-arm kettlebell thruster

A front squat with one 20 kg bell in the right-hand rack, pressing it overhead as the legs finish extending. The free arm reaches out for balance.

1°Ankle dorsiflexion
2°Knee flexion
9°Hip flexion
4°Trunk from vertical
171°Arm to trunk
20°Elbow flexion
44Ankle spacing, cm
77Hand spacing, cm
-6Knee outside ankle, cm
–Knee cave, ° inside toe line
43 / 57Load left / right, %
0Pelvis drop, cm

Load and joint demand

Load in the model: 20 kg. Balance and joint demand re-solve as you change it.

Lower back
10 / 151
Hip extensors
7 / 91
Knee extensors
16 / 83
Calves
34 / 34

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
82 pts
Shoulders
64 pts
Triceps
46 pts
Abs and core
35 pts

Effort and your quota

7.5/10 effort7.8fatigue per set

Your quota per set: 10 reps at 20 kg, stopping 2 reps short of failure.

One hard set earns 182 legs points, 110 push points, 46 arms points, 35 core points.

Prime movers

Quadriceps, gluteus maximus, deltoids, triceps, obliques.

What to look for

  • Stay square; do not lean away from the bell.
  • Drive up and let the legs start the press.
  • Bell back to the rack before you sit.
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.