Your Court Shoe Was Built For Tennis. The Foam Inside It Was Built For Walking.
Last week I got an email from a guy named Rich. He let me share it here, and I'm glad he did — because some version of it lands in my inbox every few weeks.
The name changes. The town changes. The letter never does.
I'm not a doctor and I'm not a coach. I'm a 4.5 player who's been on a court most mornings for longer than I'd like to count.
Somewhere along the way I became the guy people message when something in their game quietly stops working — and they don't want to say it out loud at the club.
It's always the same letter. The same list of things already tried. The same friend who's started suggesting they "take it easy for a while."
And the same quiet line in the last paragraph — the one that's the real reason they wrote.
Here's Rich's.
I read it twice.
Because a few years back, I'd written almost that exact email in my own head. I just never sent it to anyone.
For a long time, when someone told me their feet were falling apart, all I could do was hand over the usual stretch-and-ice advice. Most of them came back a few weeks later the same, or worse.
Then something shifted for me. Enough people have asked me to write it down that I finally did — so I could just send them this. Rich is one of them.
So if any of his email reads like your own week, give me ten minutes. I think I can save you the year I lost figuring this out the slow way.
The Blind Spot
Almost everyone who writes me has run the same playbook, in the same order. New shoes. Rest. Stretching. Ice. Something anti-inflammatory before a match. Maybe inserts, maybe the molded kind.
And still, nothing holds.
Here's what almost none of them have been told:
The thing you're dealing with in month six is not the thing you had in week two.
In the beginning, a sore plantar fascia is mostly an irritation — an inflammatory phase. That's what all the usual advice is built for: calm it down, rest it, ice it. For the first few weeks, that's reasonable.
The trouble starts when it isn't enough.
Because when the same tissue keeps getting loaded, month after month, it changes. Around the two-month mark it stops being mainly inflammation and starts becoming structural — the fibers at the attachment point wear and thin.
It isn't "angry" anymore. It's worn. There's even a separate name for that later stage: plantar fasciosis, not fasciitis.
Which quietly explains years of frustration. Most of what people keep reaching for is built for the first version of the problem — long after they've moved into the second.
And here's the part that makes it click.
Overnight, the foot does its repair work and lays fresh fibers across the worn spot. Then you take that first full-weight step in the morning — and a lot of that repair gets pulled apart before it ever set.
That "knife on the first step" isn't fresh damage. It's last night's repair coming undone.
So the real question was never "how do I rest more," or "how old am I now."
It's simpler: what keeps loading that one worn spot — and can I take some of that load off it?
Why The Usual Fixes Keep Missing It
The soft, cushioned inserts most people grab first feel great in the store. But more squish isn't more support. Soft foam packs down under load and flattens within a game or two. By the third set you're back on a flat board — just a pricier one.
Custom molded supports are useful for the job they're built for: everyday standing and walking, molded while you stand still. That's a steady, straight-down load.
It's just a different problem than a fast, sideways game.
And new shoes ship with the same stock footbed as the last pair. You swap the shoe and keep the part that was never built for what you do out there.
None of it's dumb. It's just aimed at a straight line.
And tennis isn't a straight line.
Walking loads the foot straight down. Tennis loads it sideways — the split step, the hard plant, the push off a wide ball. A hard lateral stop can drive several times your bodyweight through one foot, sideways, dozens of times a match. Right onto that worn spot.
That's why the pattern is so specific. Walk for miles, nothing. Bike for an hour, nothing. Play two hours, and you can barely make it to the car.
Same foot. Different direction of load. A footbed built for a straight line was never aimed at a sideways one.
How I Found What Finally Made A Difference
A while back the same name kept coming up — not in ads, but in tennis forums and a couple of league chats. Players my age and older, mentioning a pair of insoles that did what three pairs of shoes hadn't.
I ignored it at first. Most of that chatter is marketing. But it kept showing up from people who clearly weren't selling anything.
The brand is OnAce. When I read how they're built, it was the first insole designed around the sideways problem instead of the walking one. The arch sits differently. There's real structure right where you plant and cut.
And it's made of a completely different material than the foam in your shoe.
It's a foam called PORON — the same family used in podiatry and orthotic insoles. What makes it different is simple: it doesn't go flat.
Cheap foam compresses and stays compressed. That's why it bottoms out by the third game. PORON compresses to absorb the hit, then springs back — stop after stop, set after set.
The idea isn't to cushion harder. It's to spread that sideways load and keep a real surface under the foot — so less of the force funnels straight into the spot that keeps getting interrupted.
It's designed to take pressure off that spot, not pass it through. A structural job, not a miracle.
You don't have to take my word for it — I'd rather you didn't. There's a ten-second test, and it has nothing to do with diagnosing anything.
Pull the insole out of your court shoe. Press your thumb hard into the middle. On most shoes it just stays dented — flat and dead.
Now press your thumb into a piece of PORON. It gives as much as you push, then pushes right back.
Once you've felt the two side by side, you can't un-feel it.
They're trim-to-fit, too. Lay your old insole on top, trace, cut, drop them in. Took me two minutes in the parking lot.
I'll be honest — it took me a few weeks of playing on them before I believed it, because I kept waiting for the soreness to come roaring back. For me, the mornings were the first thing to ease up. Your mileage may vary. But I'd want to feel that difference under my own thumb.
If You're In The Same Boat As Rich
Do some quiet math with me. The shoes, the inserts, the ice every night — you've probably already put three or four hundred dollars into chasing this. Maybe a lot more.
Almost all of it on gear that shipped with the same flat foam inside.
A pair of these runs about fifty dollars. Most people order two — one for each shoe they rotate.
There's a 60-day return: play your normal schedule for two months, and if they're not doing it for you, send them back, even worn, and you get your money back. I checked that policy myself before I put a link in front of anyone.
Here's the part I'd say to a friend across the table.
Every week you spend working around it — sitting out the third set, waving off the wide ball — is a week you don't get back out there with them. That's the cost that actually matters. And no shoe sale fixes it.
It was never your age, and it was never playing too much. The one piece of gear touching your foot for fifteen hours a week was built for a straight line — and you don't play a straight-line game.
That's the whole thing. And it's the one part of this you can change tonight.
So do the thumb test on your own shoes. If the foam stays dented, you already have your answer.
And if any of this helped, send it to whoever in your group has gotten a little quieter lately. They probably know why.
This is a paid advertisement for OnAce. OnAce sponsors this article and the links above are paid placements. I bought my own first pair at full retail. Nothing here is medical advice, and nothing here is a promise of any specific result — individual experiences vary. If you have ongoing foot or joint concerns, please talk to a qualified professional.
What Other Players Are Saying
ok the thumb test in here is no joke. pulled the insole outta my gel resolutions and it just stayed dented like an old couch cushion lol. trimmed a pair of these in like 2 min. back half of my tuesday doubles feels totally different now
im out there 2-3 hrs and used to be cooked by the 2nd set. these hold up where my old ones were flat by the warmup. kinda annoyed i dropped $400 on shoes before trying a $50 insole tbh
ngl "tennis specific insole" sounded like marketing to me, foam is foam right. only ordered bc of the 60 day return so figured no risk. theyre way firmer than i expected and they actually spring back instead of squishing flat. fine, i get it now
lol same. the thumb test sold me harder than the article did
skeptical husband checking in. did the full 60 days, didnt send em back. thats all im saying 🤷
trimmed these into my k-swiss in a couple minutes, super easy. mornings have been easier which is honestly all i wanted. no notes
back to my normal week and actually looking forward to saturdays again. wish id found these a year ago
got a 2nd pair for my wife after i wouldnt stop talking about mine lol. she stopped complaining on the drive home from league so guess they work for her too
i play in narrow shoes and figured these wouldnt fit but after trimming theyre perfect. firmer than i thought, in a good way
6 months in and they still havent packed down like every insole ive ever bought. usually im on my 3rd pair by now. reordering for sure