Hinge downBalanced over midfoot
Side view
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Goblet good morning

Take care: Loads the lower back: keep it flat and stop short of where it rounds.

A 16 kg dumbbell held upright at the chest; soft knees while the trunk hinges to about 70°. The shins are solved so the load stays balanced over midfoot.

4°Ankle dorsiflexion
8°Knee flexion
8°Hip flexion
3°Trunk from vertical
44°Arm to trunk
133°Elbow flexion
30Ankle spacing, cm
14Hand spacing, cm
-3Knee outside ankle, cm
–Knee cave, ° inside toe line
50 / 50Load 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
56 / 202
Hip extensors
29 / 127
Knee flexors
19 / 57
Calves
34 / 34
Shoulder, per side
44 / 44
Elbow, per side
49 / 56

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

Hamstrings
100 pts
Glutes
82 pts
Lower back
64 pts
Upper back
23 pts

Effort and your quota

6.5/10 effort6.8fatigue per set

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

One hard set earns 182 legs points, 23 pull points, 64 core points.

Prime movers

Hamstrings, gluteus maximus, spinal erectors, upper back (holding).

What to look for

  • Push the hips back; the knees stay soft.
  • Keep the back flat and the dumbbell tight to the chest.
  • Stop when the hamstrings pull.
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.