Jogging Stroller Math?

Sometimes, getting in those running miles equates to babies going for a ride!

So, need a stroller?  Come to my house and do your shopping.  During regular business hours my wife and I will allow you to take a test drive of some of the latest stroller technology.  In raising a toddler son and recently adding a baby girl, it seems that the quantities of strollers around our house has also doubled.

First there was the family stroller – built like a tank – it accommodates an infant carrier and has the storage space of a small flatbed pickup.  Then, of course, the running stroller.  And don’t forget the umbrella stroller.  But when baby girl came along, suddenly the stroller count doubled!

I’m hoping my wife doesn’t read today’s post – a walking or running stroller with a bit of a twist.  The stroller shown below aims to “accommodate the user’s natural and synchronous arm motion while simultaneously distributing between both of the jogger’s arms the force required to propel the stroller.”

The stroller has two arm members (21) which ultimately interact with the drive tubes (23, 52).  A coupling member may be positioned between the two tubes.  According to the patent, the term coupling member includes the following exemplary definition:  mechanism for facilitating natural limb movement and facilitates an even distribution of force between the user’s arms as required to propel the stroller.  For example, the coupling member may include a bevel gear on the end of each drive tube, plus a center bevel gear (37) connecting the two.  When the user’s arms apply substantially equal forces on each arm member, each drive tube applies a rotational force to the rear wheels.  Thus, as the user runs (for example) the natural pendulum action of the user’s arms is used to drive the arm members and thus propel the stroller.

The engineers, mathematicians, and scientifically inclined may find it of interest that one of the patent’s independent claims includes the limitation that the coupling member may be defined with the mathematical equations:

The ‘y’ term equals the position of the user’s left arm.  Thus, c or -y equals the position of the user’s right arm.  The other variables include:

  • A = amplitude, and half the distance between the arm’s maximum forward position and maximum back position
  • B = period, and represents the time to complete one cycle of arm movement
  • x = time

Remember when you sat in algebra and asked the question that most every student eventually asks:  “When am I ever going to use this stuff?”  Well . . .

So, the claim in part states:  . . .  a coupling member mechanically coupled to the first arm member and to the second arm member such that the position of the first arm member relative to the position of the second arm member can be defined with the mathematical equations:

y=A sin ((2*pi/B)x)


wherein, in one complete cycle of arm movement during the act of pushing the stroller . . .

So adding JOGGING + STROLLER + MATH must equal  >>

Well, there you have it.  Today’s patent was issued on May 8, 2012. The full text may be found here (last visited May 9, 2012).  The patent appears to be owned by its inventor, Michael J. Dresher of Wichita, KS.


I write this blog without taking a position as to the usefulness, desirability, novelty, aesthetics, functionality, etc. of the products or processes discussed in my posts.  Naturally, readers are free to take any position they prefer and comment accordingly, provided it is in good taste.  However, if I am silent with respect to your comment, such silence should not be construed as any agreement or disagreement to the comment; I hope you can appreciate that I simply prefer to remain neutral in such matters and merely report Patent Office news.  Thanks!  🙂

This entry was posted in Running, Strollers and tagged , , , , , , . Bookmark the permalink.

1 Response to Jogging Stroller Math?

  1. paralleljohnny says:

    Awesome! My only question is how to steer.

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