Patent ID: 7458172

Claim:
A device for attenuating impact forces for an article of footwear, comprising: a first element including: (a) a first base portion, (b) a second base portion, wherein a space is defined between the first base portion and the second base portion, (c) a first concave side wall portion extending between the first and second base portions and into the space, and (d) a second concave side wall portion extending between the first and second base portions and into the space; and a second element at least partially included in the space, wherein the second element includes a first convex side wall portion at least partially extending in the space and a second convex side wall portion at least partially extending in the space; wherein the first and second concave side walls and first and second convex side walls are arranged in an alternating manner such that each concave side wall is immediately adjacent two convex side walls and each convex side wall is immediately adjacent two concave side walls.