Lower, eccentricBalanced over midfoot
Side view
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Single-arm overhead dumbbell extension

One 10 kg dumbbell in the right hand, upper arm pointing straight up, the elbow flexing to lower the weight behind the head.

3°Ankle dorsiflexion
2°Knee flexion
4°Hip flexion
3°Trunk from vertical
169°Arm to trunk
10°Elbow flexion
28Ankle spacing, cm
55Hand spacing, cm
-3Knee outside ankle, cm
–Knee cave, ° inside toe line
42 / 58Load left / right, %
0Pelvis drop, cm

Load and joint demand

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

Lower back
25 / 25
Hip extensors
14 / 14
Knee flexors
20 / 20
Calves
32 / 32
Shoulder, per side
12 / 27
Elbow, per side
3 / 36

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

Triceps
100 pts

Effort and your quota

1.5/10 effort1.6fatigue per set

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

One hard set earns 100 push points, 100 arms points.

Prime movers

Triceps brachii, long head emphasised.

What to look for

  • Elbow points at the ceiling, not out to the side.
  • The free hand can support the working elbow.
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.