Knee Boss: The 21-Day Challenge (Digital Guide for Players)

Knee Boss: The 21-Day Challenge (Digital Guide for Players)

$20.00
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Knee Boss: The 21-Day Challenge (Digital Guide for Players)
Lucila R.

“The doctor said patellar strap and left me to figure out which one. This one sits exactly where he showed me. Mason plays the full game now.”

Lucila R.United States ✓ Verified buyer

Knee Boss: The 21-Day Challenge (Digital Guide for Players)

★★★★★312 Reviews
◎ Figure-8 silicone pad
⚓ Two tabs. Stays centered.
🪶 48 g. He forgets it.
⇄ Left or right knee.
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UPDATE — Only 6 units left in stock, then completely out.

10,000+young players back on the court

Returns & Refunds

60 days, no questions. If he does not wear it, send it back and we refund you in full.

Keep the strap until your refund is confirmed. Return shipping is on us inside the United States. Write to us with your order number and we send the label the same day.

Materials & Quality

Matte neoprene body, 48 grams. A figure-8 silicone pad sits against the skin and holds the strap in place. Two polished metal D-rings, two adjustable tabs, zigzag stitching along both edges.

One strap fits either knee. Nothing is handed, nothing to measure.

Care: hand wash in cold water, air dry flat. No machine, no dryer, no iron.

Shipping

United States: 3 to 6 business days. Shipped the same day for orders placed before 2 pm.

Tracking number by email as soon as the parcel leaves. Free shipping on every order, no minimum.

REAL PARENTS, REAL KNEES

What parents are saying

Photos sent in by families using Stepio this season.

★★★★★

He plays so much better now. He used to slow down after ten minutes, now he's still going at the end of practice.

Nicole B. Verified buyer

★★★★★

He put it on before practice and gave me a thumbs up from the car. Two weeks in and he's not asking to sit out anymore.

Jessica R. Verified buyer

★★★★★

He puts it on himself now. I don't have to remind him, which with a 12 year old is honestly the whole battle.

Danielle W. Verified buyer

★★★★★

I bought three different straps off Amazon first. This is the only one that actually stays where you put it.

Amanda K. Verified buyer

★★★★★

It goes on with his shoes now, same routine every time. We packed it for a three game weekend and he played all of them.

Rachel P. Verified buyer

★★★★★

It lives on his desk next to the ball. Honestly that's the best review I can give, he actually uses it.

Megan T. Verified buyer

★★★★★

He doesn't hurt when he jumps anymore. He stopped hesitating on his landings, which I noticed before he did.

Kelly A. Verified buyer

Why it hurts

His knee isn't injured. It's being tugged on.

Between 10 and 15, bones grow faster than muscles. The thigh gets tight and pulls on a spot under the kneecap that hasn't hardened yet. Every jump. The strap sits on the tendon and changes the angle where it leaves the kneecap. The thigh still pulls, just not on the soft spot.

  • Moves the pull off the soft spot
  • Doesn't squeeze the whole knee
  • He feels it from the first steps

Between the kneecap and the bump. Never on the bump.

Most straps fail because of where they sit. On a growing knee the guide is right there: the bump.

A doctor who tried it

Dr. Sabero
Dr. SaberoPediatric sports medicine physician, in Boston

"Parents ask me about growing knees more than anything else. Between 10 and 15, the tendon below the kneecap pulls on bone that is still soft, which is why the pain shows up after the session and not during it. A strap sits two centimetres below the kneecap and takes part of that pull off the growth plate. Nothing is immobilised, so the kid keeps playing, and that matters: sitting out for 3 months is its own problem. It is worn for the session, not once it already hurts, and it takes a few weeks of consistent use before the difference is obvious."

Smaller than a brace. On purpose.

A sleeve wraps the whole joint and spreads its pressure everywhere, so it concentrates it nowhere. Stepio is compact so all its support lands on one spot: the tendon just below his kneecap. Small isn't a shortcut. It's the whole point.

How it works ?

Find the bump
1. Find the bump

Press just under his kneecap. The tender bump is the tibial tubercle. The strap goes above it, never on it.

Tighten each side
2. Tighten each side

Two tabs, one each side. Pull them evenly until it is snug. He should still slide a finger underneath.

Play as tolerated
3. Play as tolerated

Practice, games, tournament weekends. Take it off after. Stretch 3 to 4 times a day.

WHO IT'S FOR

Built for the growth spurt, not the week

Basketball, 10 to 15
⛹Basketball, 10 to 15

Layups, rebounds, 4-game weekends. The 1-leg landing is where it pulls hardest.

Mid growth spurt
↗Mid growth spurt

Outgrew his jeans in 3 months? That's the window the bump shows up in.

Told to wait it out
⏳Told to wait it out

Rest, ice, Advil. Then practice again. Here's the part between the two.

Already tried a strap
↻Already tried a strap

Slid down, flopped around, was made for an adult. This one fits a 12-year-old.

Why Stepio?

STEPIO
STEPIO
KNEE SLEEVE
KNEE SLEEVE
ADULT STRAP
ADULT STRAP
Sits between kneecap and bump
✓
✕
✓
2 tabs, stays centered
✓
✕
✕
Fits ages 10 to 15
✓
✕
✕
48 g, under the short
✓
✕
✓
Looks like gear, not a brace
✓
✕
✕
Doesn't squeeze the whole knee
✓
✕
✓

The surgeons' guide names one thing to wear: a patellar tendon strap.

Questions parents ask

Where exactly does it go?

Between the bottom of the kneecap and the bump. Never on the bump. The orthopedic surgeons' parent guide (AAOS OrthoInfo) describes it as worn “just between the bottom of the kneecap and the bump on the tibial tubercle.”

Does it cure Osgood-Schlatter?

No. Nothing cures it, and anyone who tells you otherwise is selling you something.

Osgood-Schlatter is not an injury you repair. It is a growth plate under strain, and it settles on its own when the growth spurt ends. No strap, no cream, no supplement shortens that. What you can do is manage it: move where the tendon pulls so he keeps playing as tolerated, and stretch 3 to 4 times a day as the orthopedic surgeons' guide recommends.

That is what Stepio is for. Not a cure. A way through the growth spurt.

Is it safe for him to keep playing?

The AAOS writes: “It is safe for children to participate in activities as tolerated” and “continued participation in activity will not cause long-term damage to the knee.” Ask his doctor about his case.

What size do I need?

It fits ages 8 to 16 with 2 adjustable tabs. It's adjustable to fit any size, so your child can keep wearing it as they grow

Will it slide down during a game?

2 tabs, 1 on each side, keep the pad centered on the tendon. The silicone holds it on the skin. Nothing to fix at halftime.

Is there any research on straps?

Yes, and we'll be honest about it. On adults, infrapatellar straps reduced calculated tendon strain at the sore spot by about a third in most subjects (Lavagnino et al., 2011). In 16 teenage basketball and volleyball players, pain on the 1-leg jump dropped with no loss of jump height (Dar, 2019). A pilot on 230 children with Osgood-Schlatter found less pain during and after training than placebo (Ilbrink, 2017). Small studies, short term, not a cure.

What if it's not right for him?

60 days. If he doesn't wear it, send it back, full refund.

4.8 ★★★★★

312 reviews

Write a review
★★★★★
D✓ Danielle R.Verified purchase

The doctor said patellar strap and left me to figure out which one. This one sits exactly where he showed me. Mason plays the full game now instead of sitting out the fourth quarter.

★★★★★
M✓ Marcus T.Verified purchase

He is 12 and every adult strap we tried slid down by halftime. This one has two tabs so we tighten each side. It has not moved once in six weeks of practice.

★★★★★
P✓ Priya S.Verified purchase

He used to limp to the car after games and I hated watching it. Three weeks in, he walks out normally. He puts it on himself now, I do not even have to ask.

★★★★★
K✓ Kevin B.Verified purchase

Bought one, ended up ordering a second for his gym bag. He forgets it at school otherwise.

★★★★★
A✓ Alicia M.Verified purchase

My daughter plays AAU and the bump under her knee was killing her. This helped more than the ice packs ever did.

★★★★★
T✓ Tom W.Verified purchase

Easy to put on, stays flat under his shorts. He says he barely feels it.

★★★★★
R✓ Renee G.Verified purchase

Pediatrician mentioned Osgood-Schlatter. We ordered the same night. Two months later he is still playing three times a week.

★★★★★
D✓ Darnell P.Verified purchase

Good build quality for the price. The metal rings feel solid, not cheap plastic like the last one.

★★★★★
H✓ Hannah K.Verified purchase

Works well, but be honest with yourself about the first two weeks. He complained every single day before he got used to it. Now he puts it on without being asked.

★★★★★
S✓ Steve L.Verified purchase

My son wore it through a four game tournament weekend. No complaints, no sliding.

★★★★★
Y✓ Yasmin A.Verified purchase

He actually wears it, which is the whole battle. It looks like gear, not like a medical brace.

★★★★★
B✓ Brian K.Verified purchase

I still have the bump at 42. Nobody gave me anything like this when I was his age. Glad he has it.

★★★★★
M✓ Megan R.Verified purchase

Three weeks and the difference walking down stairs is obvious. He takes them normally now.

★★★★★
C✓ Chris D.Verified purchase

Arrived in four days. Fits my 13 year old perfectly, he is tall for his age.

★★★★★
N✓ Nadia F.Verified purchase

The silicone pad sits right where it should. You can feel it is in the correct spot the moment you put it on.

★★★★★
P✓ Paul O.Verified purchase

Second one ordered. First is still going strong after three months of daily use.

★★★★★
T✓ Tasha B.Verified purchase

He complained about it the first day because it was new, then forgot about it completely.

★★★★★
G✓ Greg H.Verified purchase

Does the job. The tabs are a bit long on a small leg and the extra sticks out under the short. Not a dealbreaker, just not perfect.

★★★★★
L✓ Linh N.Verified purchase

Clear instructions on where to place it. That part mattered more than I expected.

★★★★★
J✓ Jordan C.Verified purchase

My son said it feels like his knee is being held up instead of squeezed. That is exactly the difference.

★★★★★
E✓ Emily V.Verified purchase

Washed it by hand a few times, still looks new. No fraying at the edges.

★★★★★
R✓ Rashid A.Verified purchase

Coach noticed he stopped favouring the leg during drills. Did not even tell him we got this.

★★★★★
S✓ Sandra P.Verified purchase

Only complaint is I wish it came in a two pack by default. Ended up ordering twice.

Stepio

Thanks Sandra. Noted, we are looking at a pair option. In the meantime the second one ships just as fast.

★★★★★
M✓ Mike J.Verified purchase

Does what it says. He plays, he does not limp after. Simple.

★★★★★
C✓ Carla M.Verified purchase

Good product. I would have liked clearer sizing info before ordering, I was not sure it would fit an 11 year old. It does, but I guessed.

★★★★★
D✓ Devon R.Verified purchase

Honestly bought it expecting nothing. Pleasantly surprised. He asks for it before practice now.

★★★★★
A✓ Amira H.Verified purchase

Good for growing kids. My older one used it last year, now the younger one has it.

★★★★★
S✓ Scott F.Verified purchase

Solid. Took him two tournaments to stop fiddling with it mid-game. After that, no complaints.

★★★★★
B✓ Bianca T.Verified purchase

The bump is still there but it is not sore like it was. He can kneel again.

★★★★★
O✓ Omar S.Verified purchase

Shipping was quick and it came with a card explaining the placement. Useful.

★★★★★
K✓ Katie D.Verified purchase

Ordered Monday, had it Thursday, he wore it to Saturday practice. No issues.

★★★★★
J✓ Jamal W.Verified purchase

I like that it does not cover the whole knee. He hated the sleeve he had before, too hot.

★★★★★
E✓ Erin L.Verified purchase

Worth it just to stop hearing him say his knee hurts after every game.

★★★★★
V✓ Victor A.Verified purchase

Size was my worry and it turned out to be a non-issue. You just tighten it.

★★★★★
N✓ Noelle B.Verified purchase

He is 14 and growing fast. It still fits after six months, we just loosened it.

★★★★★
T✓ Ty R.Verified purchase

Works for my son and I ended up buying one for myself for running. Same idea.

★★★★★
G✓ Grace O.Verified purchase

Bought before a tournament week. He got through all of it without sitting out.

★★★★★
A✓ Andre M.Verified purchase

The carbon look on the front is what sold him. He thinks it looks fast.

★★★★★
L✓ Leila K.Verified purchase

Fabric is soft against the skin, no rubbing after a long practice.

★★★★★
D✓ Dan P.Verified purchase

Had a question about placement and got an answer the same day. Good service.

Stepio

Happy to help Dan. Between the bottom of the kneecap and the bump, never on the bump.

★★★★★
S✓ Sophia N.Verified purchase

He stopped asking to skip practice. That is how I know it is working.

★★★★★
M✓ Marcus L.Verified purchase

Been through a full season. Still holds, still looks fine.

★★★★★
I✓ Ivy C.Verified purchase

My 10 year old uses it for gymnastics. Fits her fine with both tabs tightened all the way.

★★★★★
R✓ Rob S.Verified purchase

Nothing fancy, it just stays where you put it. That is all I wanted.

★★★★★
D✓ Dalia M.Verified purchase

He tried a cheap one off a marketplace first. Night and day, this one actually stays.

★★★★★
K✓ Keith A.Verified purchase

Good value. Cheaper than one visit to the physio and he wears it every day.

★★★★★
M✓ Mona B.Verified purchase

Easy to adjust mid-game. He loosens it on the bench and tightens it going back in.

★★★★★
T✓ Trevor H.Verified purchase

Fits under compression shorts without bunching up.

★★★★★
A✓ Aisha T.Verified purchase

12 of the 18 boys on their team had the bump at the same time. Coach keeps two spares in his bag now.

★★★★★
N✓ Nathan G.Verified purchase

Three months in. No regrets, no complaints, he plays.

60-day guarantee

If he doesn't wear it, you get your money back. No questions.

Still have a question?

Sizing, timing, whether a strap is even the right call for your kid. Ask us before you buy.

Our team answers 7 days a week, 8 am to 9 pm ET, and a real person replies.