Lower, eccentricBalanced over midfoot
Side view
Drag to orbit, pinch or scroll to zoom

Kettlebell overhead triceps extension

Standing, one 16 kg bell held upside down by the horns, the bell continuing the line of the forearms; the upper arms point up and the elbows bend from nearly straight to about 140°.

3°Ankle dorsiflexion
2°Knee flexion
4°Hip flexion
3°Trunk from vertical
170°Arm to trunk
9°Elbow flexion
28Ankle spacing, cm
12Hand 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
30 / 30
Hip extensors
16 / 16
Knee flexors
22 / 22
Calves
35 / 45
Shoulder, per side
15 / 22
Elbow, per side
8 / 29

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 16 kg, stopping 2 reps short of failure.

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

Prime movers

Triceps brachii, long head emphasised by the overhead position.

What to look for

  • Elbows point forward and up, not wide.
  • Ribs down; no arching.
  • Lower slowly behind the head.
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.