Footwear: Stress Relief?
A podiatric surgeon and tennis professional says for performance and protection, players and manufacturers need to change priorities when it comes to tennis shoes.
By Kent Oswald
While pretty much everyone knows not to judge a book by its cover, too few apply that knowledge when they purchase tennis shoes. It’s as if they live in a fantasy land where the shoes they slip on in the store will feel and respond the same after hours — not to mention months — of having ounces of foam and rubber stood on, jumped on and slid on by pounds of player.
Among those with a mission to change minds and improve the situation for feet is Dr. Allan Grossman, a board-certified podiatric surgeon in Pennsylvania whose residency was at Harvard Medical Center. Grossman has solid on-court credentials: He’s a former ranked junior player, a current USPTA pro, and a tennis coach at Franklin & Marshall.
Overgeneralized, Grossman’s reasoning is that feet need bolstering in their role as the foundation for the body in terms of the stresses during play on ankles, knees, back, etc., as well as for the footwork necessary to hit effective groundstrokes.
“The physicality of the game has totally changed over last 10 years and shoes, interestingly, have not really changed,” he says. Having tested playing tennis in running shoes and found them much more stable for tennis than he had expected — but not nearly durable enough — Grossman centers much of his critique on how running-shoe manufacturers addressed that sport’s concerns (and admittedly much larger market) to a greater degree than is done for tennis.
He also calls out the design and construction for the internal cushioning and support in shoes, which is mostly based on findings from “force-plate” testing and impressionistic reporting by testers. (Force-plate testing measures pressure exerted on the sole when someone walks or runs over a flat, metal surface.)
Both force-plate testing and impressionistic reporting can offer insights, but, as Grossman sees it, should not take the place of analysis of the foot biomechanics taking place inside the shoe during actual play. The mantra for his practice and teaching — at his base at the Harrisburg (Pa.) Foot and Ankle Center, on USTA committees, as an industry consultant, and university professor — is always, “evidence-based medicine is what really needs to happen.”
Of particular interest was research he did that involved applying a sheet of sensors to a foot and pressure-mapping (tracking the changes in how a foot stresses) during simulated play. Not surprisingly, there was “a great disparity between computer-based testing and what testers say they experience.” [Video of a representative sample of the testing can be seen at youtu.be/ro1zup6pRTQ]
While everyone is aware tennis requires the foot to move in a greater variety of ways in general — stresses multiplied when considering the challenges of different surfaces and “innovations” such as the increase of sliding on hard courts — most shoes seem to be created with priorities of, first fashion, then outsole durability and weight, and, finally, internal comfort.
Issues that are not being addressed, according to Grossman, include feedback from players without hearing from any who spend months in the shoes, as do most wearers. He also questions how often people receive proper fittings or are offered shoes with flex points that adequately fit their play.
Most of all, because there is not enough testing with in-shoe sensors, Grossman fears the internal workings are designed and developed without regard to how players will put unexpected stress first on their shoes, and then injurious stresses on their feet. Even more, they might not have the opportunity to even try on the shoe that is right for their body and playing style given the smallish selection at most retailers. That shoe sizes are not true across brands and there are no industry-wide accepted measurements for shock absorption and support adds to the complexity of making sure the shoe fits.
He insists there are good shoes available and adamant that he is not “anti-manufacturer.” But, “We’re focused on the racquet and string,” Grossman says, “and not on addressing footwork, the most important part of game.
“People need to know that there is more to [their health and game] than walking into a store, trying something on and saying, ‘This looks like a good shoe.’ Forces and stresses lead to injuries and manufacturers need to understand the mechanics of the game. Right now, all I want to do is raise questions.”
Selling the ‘Right’ Shoes
Dr. Allan Grossman says tennis retail sales staff needs to be trained properly. While for decades, fashion has been a priority among tennis shoe buyers, there are other considerations. A few issues retail staff should know about when dealing with customers:
- Feet have slightly different shapes when sitting and standing.
- If a customer’s second toe is longer than the big toe, check fit using the second toe.
- Most people have one foot that’s larger than the other; make sure you fit the larger foot.
- Encourage a customer to try on the shoes and move in a way similar to how they’d react on a tennis court.
- Try to make sure flex points in the shoe adequately fit with a person’s style of play.
See all articles by Kent Oswald
About the Author
Kent Oswald is a contributor to TennisNow.com, producer at the JockBookReview.com and a former editor of Tennis Week magazine.