Hold
Side view
Drag to orbit, pinch or scroll to zoom

Copenhagen plank

Side plank on the right forearm with the top leg resting on a bench and the bottom leg hanging free. The top leg’s adductors hold the body up.

-20°Ankle dorsiflexion
10°Knee flexion
18°Hip flexion
84°Trunk from vertical
90°Arm to trunk
90°Elbow flexion
6Ankle spacing, cm
12Hand spacing, cm
-8Knee outside ankle, cm
–Knee cave, ° inside toe line
–Load left / right, %
-17Pelvis drop, cm

Load and joint demand

Bodyweight exercise: the load slider has no effect here; body mass comes from your limits.

No gravity-based joint demand to show for this exercise.

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

Adductors
60 pts
Abs and core
49 pts
Lower back
38 pts

Effort and your quota

4.5/10 effort4.5fatigue per set

Your quota per set: hold 25 s, stopping 2 reps short of failure.

One hard set earns 60 legs points, 88 core points.

Prime movers

Adductors of the top leg, obliques, quadratus lumborum.

What to look for

  • Short lever (knee on bench) first, then foot on bench.
  • Hips stay in line with the shoulders.
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.