RaiseBalanced over midfoot
Side view
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Dumbbell scaption

Light 6 kg dumbbells raised with straight arms and the thumbs up in the scapular plane, about 35° forward of straight out to the side, to shoulder height.

4°Ankle dorsiflexion
2°Knee flexion
3°Hip flexion
3°Trunk from vertical
6°Arm to trunk
8°Elbow flexion
26Ankle spacing, cm
46Hand spacing, cm
-2Knee outside ankle, cm
–Knee cave, ° inside toe line
50 / 50Load left / right, %
0Pelvis drop, cm

Load and joint demand

Load in the model: 6 kg each hand. Balance and joint demand re-solve as you change it.

Lower back
22 / 81
Hip extensors
13 / 40
Knee flexors
19 / 34
Calves
33 / 33
Shoulder, per side
6 / 51
Elbow, per side
4 / 23

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

Shoulders
100 pts
Upper back
46 pts

Effort and your quota

2.5/10 effort2.6fatigue per set

Your quota per set: 10 reps at 6 kg each hand, stopping 2 reps short of failure.

One hard set earns 100 push points, 46 pull points.

Prime movers

Supraspinatus, anterior and lateral deltoid, serratus anterior, lower trapezius.

What to look for

  • Thumbs up, arms in a shallow V in front of you.
  • Stop at shoulder height.
  • Keep the shoulders down away from the ears.
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.