Shift downCentre of mass inside base of support
Side view
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Kettlebell cossack squat

Very wide stance, a 16 kg bell held by the horns at the chest; the pelvis travels sideways and down over the right foot while the left leg straightens out to the side. The bell in front helps counterbalance.

-6°Ankle dorsiflexion
5°Knee flexion
26°Hip flexion
5°Trunk from vertical
44°Arm to trunk
128°Elbow flexion
90Ankle spacing, cm
12Hand spacing, cm
-18Knee outside ankle, cm
–Knee cave, ° inside toe line
51 / 49Load left / right, %
0Pelvis drop, cm

Load and joint demand

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

Lower back
64 / 124
Hip extensors
34 / 75
Knee extensors
33 / 48
Calves
48 / 48

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

Adductors
100 pts
Quads
82 pts
Glutes
64 pts
Upper back
23 pts

Effort and your quota

7/10 effort7.3fatigue per set

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

One hard set earns 246 legs points, 23 pull points.

Prime movers

Adductors, quadriceps, gluteus maximus, upper back (holding).

What to look for

  • The straight leg stretches the inner thigh.
  • Heel of the working foot stays down.
  • Elbows inside the knee, chest tall.
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.