Walk
Side view
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Crab walk

Sitting with the hands on the floor behind the shoulders and the feet flat in front, the hips lifted off the floor, walking feet first: the opposite hand and foot step together. Shown on the spot.

-14°Ankle dorsiflexion
103°Knee flexion
61°Hip flexion
57°Trunk from vertical
78°Arm to trunk
32°Elbow flexion
28Ankle spacing, cm
46Hand spacing, cm
4Knee outside ankle, cm
–Knee cave, ° inside toe line
–Load left / right, %
0Pelvis 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

Triceps
100 pts
Glutes
82 pts
Hamstrings
64 pts
Upper back
46 pts
Abs and core
35 pts

Effort and your quota

6/10 effort6fatigue per set

Your quota per set: 30 s hard, stopping 2 reps short of failure.

One hard set earns 146 legs points, 100 push points, 46 pull points, 100 arms points, 35 core points.

Prime movers

Triceps, gluteus maximus, hamstrings, posterior deltoids, abdominals.

What to look for

  • Lift the hips and keep them up.
  • Hands under the shoulders, fingers toward the feet.
  • Opposite hand and foot move together.
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.