U.S. and Canadian women's soccer teams.

Small Ball Promoted for Women’s Soccer

Does women’s soccer need a smaller, lighter ball? That’s the idea behind the Eir, offered by a new Danish company of that name.

Women have a higher rate of concussion and knee injury in soccer, and Eir argues that this is because soccer balls were designed for men.

Currently in the United States, size 5 balls are used for everyone, male and female, starting at age 13. A size 5 to a woman would be like a size 7 to a man. To show you what that would look like, Eir created this video.


Not only would women’s soccer involve fewer injuries, it would be a faster game, the company claims:

By adjusting the circumference and weight of the ball we:

  • Reduce knee pressure from (up to) 80% down to 2%
  • Reduce leg strain by up to 40%
  • Increase ball speed by 13%
  • Reduce the acceleration force from a level above to 17% below that of concussions.

The company cites its own, apparently unpublished, research on small balls.

The New York Times reports that the company founder, Majken Gilmartin, had seven surgeries for soccer-related knee injuries, starting at age 16.

Women’s Soccer Ball Research Lacking

A size 5 ball measures 27-28 inches in circumference and weighs 14-16 ounces. The Eir ball is 26.4 inches in circumference and 13 ounces. That’s just slightly larger than a size 4 ball: 25-26 inches, 11-13 ounces. The company says it arrived at the dimensions for its small ball for women’s soccer after careful research.

One question these claims raise is whether size 5 balls are ideal for anyone. The dimensions of the size 5 ball was first set by FIFA in 1872 and slightly revised in 1937.  It’s hard to know what criteria were used. Would a smaller or lighter ball result in fewer injuries in men as well? Scanning the medical literature, I don’t see much research on soccer ball size at all. Certainly the character of the game would change with the ball.

The idea of different equipment for women is not new to sports. In organized women’s basketball, the balls are an inch smaller in circumference than the balls used in men’s basketball.

The Danish Football Association has approved the Eir ball for girls’ and recreational women’s soccer. Should it be used in competition? The idea is intriguing, but I’d like to see more evidence before recommending it.

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2 thoughts on “Small Ball Promoted for Women’s Soccer”

  1. Women’s soccer ball size.
    Why is this not a huge issue? Not only would there be fewer injuries but the very nature of the game would change. A smaller ball would mean that the players could actually wrap their foot around the ball whilst passing and shooting and importantly get their touch play more exact when it comes to control and one touch passing. Watching the women’s game with the size 5 is like watching old rain affected games in the 50s and 60s as the players tried to heave the heavy water soaked leather ball around the park.

    1. A very interesting analogy. It would be interesting to watch some women’s games with the smaller ball to see if it makes a difference.

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