What a strap below the kneecap actually does

The tendon under the kneecap

The patellar tendon runs from the bottom of the kneecap to the top of the shin. The muscles at the front of the thigh pull on it to straighten the knee, which is why stairs, hills, squatting and standing up load it hardest. When it becomes irritated, the pain is usually local: a tender point right under the kneecap that flares with those movements and eases with rest. Clinicians call this patellar tendinopathy; most people know it as jumper's knee or, loosely, runner's knee.

What pressure on the tendon changes

An infrapatellar strap applies a band of pressure across the tendon a little below the kneecap. The working idea, studied in sports medicine for decades, is that this changes the mechanics of the tendon during movement: the effective length of the loaded segment, the angle at which force reaches its attachment, and how the kneecap tracks. It is the same principle behind the strap on a tennis-elbow support.

For the person wearing it, the useful version of that sentence is simpler: the loaded spot shifts slightly, the step feels more controlled, and the tendon gets a gentler day while it settles. The effect is present while the strap is worn. It is support, not therapy.

Who tends to benefit

• Pain that sits just below the kneecap and flares on stairs, hills, kneeling or after long walks.
• People who want to keep walking, gardening and working while a sore tendon calms down.
• Runners and walkers who feel the front of the knee on descents.

Who it is not for

• Swelling after a fall or twist, a knee that locks or gives way, or pain deep inside the joint. Those need a clinician, not a strap.
• Pain along the inside or outside of the knee rather than under the kneecap.
• Anyone whose pain has lasted more than a few weeks without being looked at. Wear the strap by all means, but book the appointment.

Why the details of the strap matter

The pressure only helps if the pad is on the tendon and stays there. A pad that slides onto the shin is doing nothing. That is the whole reason the June Strap has a gel-grip inner and a dial you can set with one hand: the placement you get right in the morning is the placement you still have at the top of the hill. See how it works.

Care of June is a support product, not a medical device or a treatment. Nothing on this page is medical advice. If you are unsure what is causing your knee pain, see a physiotherapist or doctor.