Press, concentricBalanced over midfoot
Side view
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Bottoms-up kettlebell press

A 12 kg bell held upside down, bell balanced above the fist, pressed from in front of the right shoulder to lockout. Any wobble shows: the grip and the shoulder have to stay square.

2°Ankle dorsiflexion
2°Knee flexion
6°Hip flexion
2°Trunk from vertical
34°Arm to trunk
149°Elbow flexion
32Ankle spacing, cm
48Hand spacing, cm
-5Knee outside ankle, cm
–Knee cave, ° inside toe line
50 / 50Load left / right, %
0Pelvis drop, cm

Load and joint demand

Load in the model: 12 kg. Balance and joint demand re-solve as you change it.

Lower back
35 / 35
Hip extensors
19 / 19
Knee flexors
23 / 23
Calves
33 / 33

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

Shoulders
100 pts
Triceps
82 pts
Upper back
64 pts
Forearms and grip
46 pts

Effort and your quota

3.5/10 effort3.7fatigue per set

Your quota per set: 10 reps at 12 kg, stopping 2 reps short of failure.

One hard set earns 182 push points, 64 pull points, 105 arms points.

Prime movers

Anterior and lateral deltoid, triceps, rotator cuff, forearms (crushing the handle).

What to look for

  • Crush the handle; the bell balances above the fist.
  • Forearm vertical the whole way.
  • Go light: the balance is the point.
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.