Descent, eccentricCentre of mass outside base of support
Off balance
Side view
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Bulgarian split squat

Rear foot laces-down on a 45 cm bench, 16 kg dumbbells. Pelvis descends with a slight forward lean; the front leg takes most of the load.

-25°Ankle dorsiflexion
5°Knee flexion
37°Hip flexion
6°Trunk from vertical
8°Arm to trunk
0°Elbow flexion
20Ankle spacing, cm
44Hand spacing, cm
-1Knee outside ankle, cm
–Knee cave, ° inside toe line
–Load left / right, %
0Pelvis drop, cm

Load and joint demand

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

Lower back
38 / 77
Hip extensors
22 / 46
Knee extensors
1 / 21
Shins
393 / 393

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
100 pts
Adductors
82 pts
Abs and core
19 pts

Effort and your quota

8/10 effort8.3fatigue per set

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

One hard set earns 282 legs points, 19 core points.

Prime movers

Quadriceps and gluteus maximus of the front leg, adductors; rear hip flexors stretched.

What to look for

  • Most of the weight stays on the front foot; the rear foot is for balance.
  • A slight forward lean shifts work toward the glute.
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.