Lower, eccentric
Side view
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Single-arm dumbbell bench press

Flat bench, one 30 kg dumbbell pressed by the right arm while the left hand holds the bench. The trunk resists being pulled toward the dumbbell.

-15°Ankle dorsiflexion
79°Knee flexion
39°Hip flexion
87°Trunk from vertical
91°Arm to trunk
16°Elbow flexion
60Ankle spacing, cm
37Hand spacing, cm
6Knee outside ankle, cm
–Knee cave, ° inside toe line
–Load left / right, %
0Pelvis drop, cm

Load and joint demand

Load in the model: 30 kg. Balance and joint demand re-solve as you change it.

Shoulder, per side
9 / 54
Elbow, per side
13 / 68

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

Chest
100 pts
Shoulders
82 pts
Triceps
64 pts
Abs and core
46 pts

Effort and your quota

4/10 effort4.2fatigue per set

Your quota per set: 10 reps at 30 kg, stopping 2 reps short of failure.

One hard set earns 246 push points, 64 arms points, 46 core points.

Prime movers

Pectoralis major, anterior deltoid, triceps, obliques.

What to look for

  • Keep both shoulders on the bench.
  • Lower the dumbbell beside the chest.
  • Press until it is over the shoulder.
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.