Step back and dropCentre of mass inside base of support
Load 62% on the right
Side view
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Kettlebell rack lunge

Reverse lunge with one 16 kg bell in the right-hand rack; the left arm reaches out for balance. The one-sided front load works the trunk as well as the legs.

4°Ankle dorsiflexion
5°Knee flexion
3°Hip flexion
2°Trunk from vertical
26°Arm to trunk
146°Elbow flexion
20Ankle spacing, cm
70Hand spacing, cm
-1Knee outside ankle, cm
–Knee cave, ° inside toe line
38 / 62Load 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
43 / 62
Hip extensors
23 / 35
Knee extensors
21 / 72
Shins
36 / 314

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

Glutes
100 pts
Quads
82 pts
Adductors
64 pts
Abs and core
46 pts

Effort and your quota

7.5/10 effort7.8fatigue per set

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

One hard set earns 246 legs points, 46 core points.

Prime movers

Gluteus maximus, quadriceps, adductors, obliques.

What to look for

  • Stay square to the front.
  • Elbow on the ribs, wrist straight.
  • Back knee down softly.
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.