Fast arm-swing tether
Fast Arm-Swing Tether supports lower arms and allows a runner or walker to maintain maximum stride frequency. Tethered thumbs/hands raise natural frequency of pendulum motion of arm swing to ensure that stride rate is not limited by slow arm movement. The tethers keep hands and arms up and reduce lower-arm moment of inertia, thus allowing the lower arms to swing essentially as point masses, resulting in a higher natural frequency of pendulum motion of arm swing to ensure stride frequency is not limited by slow arms. Supporting the hands also reduces effort required to swing arms or to keep elbows locked. This invention relieves arm fatigue for long distance running or walking in addition to allowing greater arm movement. Fast Arm-Swing Tether could be made in any fashion as long as a frontal extension can provide adequate support to hang pendulum tethers to keep hands elevated.
A classical freshman physics class multiple choice problem poses the following scenario with two almost identical pendulums, both having the same length and the same mass at the end. However, the mass on the first pendulum is a point mass whereas the mass on the second pendulum is distributed as a disk although with exactly the same amount of mass and same location for its center of gravity. With ω as that natural frequency of oscillation, the multiple choices are 1) ω of first pendulum is higher than ω of second pendulum, 2) ω of first pendulum is lower than ω of second pendulum, and 3) ω of first pendulum is same as ω of second pendulum.
The correct answer is 1, with the first pendulum swinging faster than the second pendulum. As a short answer, the distributed mass of the second pendulum has greater moment of inertia and thus a slower natural frequency. Put it another way, if both pendulums are displaced and released from the same height, the same gravitational potential energy would be converted to kinetic energy at the lowest point. The kinetic energy of the first pendulum is just the point mass swinging as a pendulum, but the second pendulum has the same amount of mass swinging as a pendulum plus the rotational energy of the disk. Since both pendulum must have the same total kinetic energy, the second pendulum has to swing slower as part of its gravitational potential energy is shared in disk rotation.BRIEF SUMMARY OF THE INVENTION
A good runner or walker (for simplicity, runner is used from here on to denote both running and walking) would never consider running with a set of dumbbells, or hand weights. Since the weights slow arm swings and hand movement, dropping them would allow quicker hands and corresponding strides, at a faster rhythm than with the hands weighed down. If a runner can go faster by discarding hand weights, should it not follow immediately that even faster results may be feasible with additional hand-weigh reductions, like chopping off the hands? While we would like to improve performance, amputation seems to be a rather drastic extreme.
Fast Arm-Swing Tether (hereinafter FAST) provides the same effect but without loss of hand usage. FAST supports the lower arms and allows a runner to maintain high stride frequency. FAST keeps hands and arms up and virtually eliminates effect of lower-arm moment of inertia, thus raising the natural frequency, of pendulum motion of arm swing to ensure stride frequency is not limited by slow arms. Elevating hands also reduces the effort required to swing arms or to keep elbows locked. FAST relieves arm fatigue for long distance running in addition to allowing greater arm movement. FAST could be made in any fashion as long as a frontal extension support can provide adequate rigidity and stability to hang pendulum tethers to keep hands elevated.
Thus pendulum 10 and support 20 in
As a schematic side view of shoulder pads that provide the essential elements of
It should be obvious to designers knowledgeable of the art that the FAST invention could take many forms, for example by adapting an extension support that is attached to a sports bra's underwire. However, all forms must rely on the heart of this invention, pendulum 10 and support 20 from
1. A fast arm swing device for walking or running comprising
- an apparatus worn by an athlete having rigid extension support and two pendulums;
- with said pendulums each having a loop to support thumbs or hands;
- with said rigid extension support located in front of and away from chest;
- with the rigid extension support effective to hang the pendulums and lower arms;
- with the pendulums keeping about parallel to upper arms; and
- with each group of pendulum, upper arm, and lower arm swinging together to form about parallelogram shape.
Filed: Sep 25, 2006
Publication Date: Mar 27, 2008
Inventor: Andrew W. Chow
Application Number: 11/526,288