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

Rear foot laces-down on a 45 cm bench, 50 kg on the back. The 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
35°Arm to trunk
138°Elbow flexion
20Ankle spacing, cm
84Hand 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: 50 kg. Balance and joint demand re-solve as you change it.

Lower back
13 / 66
Hip extensors
10 / 42
Knee extensors
18 / 40
Shins
490 / 490
Shoulder, per side
63 / 63
Elbow, per side
40 / 40

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

9/10 effort9.4fatigue per set

Your quota per set: 10 reps at 50 kg, 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.
  • Lower until the back knee nearly touches the floor.
  • Keep the bar level over the front foot.
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.