11. The lower jaw is very deep, resulting in a lengthened moment arm of the jaw muscles. 12. However, the rectus femoris moment arm is greater over the knee than the hamstring knee moment. 13. The distance from this axis to the sprung center of gravity height is the roll moment arm length. 14. To offset this effect, the skis had evolved to be much shorter, reducing the moment arm . 15. The rectus femoris biarticular muscle acting over the hip has a smaller hip moment arm than the hamstrings. 16. A shorter tail could counteract the torsion caused by the greater moment arm of the very long spikes. 17. The solution was simply to make the ski considerably shorter, reducing the moment arm and counteracting these effects. 18. A spade works in the same manner as a horn but is more efficient due to the longer moment arm . 19. This is caused by the center of lift and drag being further above the CG and having a longer moment arm . 20. This allows the foot to remain in contact with the ground for longer amount of time while decreasing the moment arm .
