Step upCentre of mass inside base of support
Side view
Drag to orbit, pinch or scroll to zoom

Lateral step-up

Standing beside a 30 cm box; the near foot steps up sideways and the pelvis rises over it while the trailing foot comes up to the box.

40°Ankle dorsiflexion
96°Knee flexion
71°Hip flexion
15°Trunk from vertical
17°Arm to trunk
0°Elbow flexion
44Ankle spacing, cm
44Hand spacing, cm
-6Knee outside ankle, cm
0°Knee cave, ° inside toe line
54 / 46Load left / right, %
0Pelvis drop, cm

Load and joint demand

Load in the model: 10 kg each hand. Balance and joint demand re-solve as you change it.

Lower back
66 / 66
Hip extensors
40 / 40
Knee extensors
41 / 55
Calves
23 / 44

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

Effort and your quota

5.5/10 effort5.7fatigue per set

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

One hard set earns 182 legs points.

Prime movers

Gluteus medius and maximus, quadriceps of the working leg.

What to look for

  • Push through the box foot; the floor foot should not help.
  • Front view shows the sideways path.
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.