Stronger Knees Are Functional Knees
Photo: Intenza Fitness on Unsplash
When patients see “severe arthritis” on an X-ray report, many assume the only answer left is surgery. Often, it isn’t. How strong your knee is has a lot to do with how much arthritis hurts and how much you can do, and strength is something you can build.
A lesson from football
American football is hard on knees. In a study of elite college players evaluated at the NFL Combine, about 15% of the knees that needed imaging already showed arthritis-level cartilage loss or joint-space narrowing, mostly in knees with previous meniscus or ACL surgery. Yet these were young men in their early twenties performing at the highest level of their sport.
After football ends, the picture changes. Retired NFL players under 60 report arthritis more than three times as often as other men their age. Old injuries matter, but so does what happens when daily, high-level training stops.
The X-ray is only part of the story
X-ray findings and symptoms often don’t match. In a review of population studies, the share of people with X-ray arthritis who actually had knee pain ranged from 15% to 81%. Two knees can look the same on film and behave completely differently. One of the biggest reasons is the muscle that supports the joint.
Strong quadriceps protect the knee
Weak thigh muscles (quadriceps) are linked to a higher chance of developing painful knee arthritis. A 2022 review of nearly 47,000 people found higher odds in both women and men with weak quadriceps.
In people who already have arthritis or are at risk for it, weaker quadriceps are linked to worsening pain and function over time, even though they were not linked to faster narrowing of the joint space on X-ray.
Exercise therapy for knee arthritis improves pain, function and quality of life. The most recent Cochrane review found no single type of exercise clearly better than another. The best program is the one you will keep doing.
In my experience, many people with severe arthritis can live a functional life when they strengthen their knee, and many reach a reasonable outcome without needing surgery.
The Stronger Knees program
That’s why I recommend this program to my patients with knee arthritis. It’s simple, and it’s worth your time:
It targets what you can change. You can’t undo what’s on the X-ray, but you can build the muscle that carries your knee.
It fits your life. About 30 minutes most days, at home, at the gym or with a physical therapist.
It’s low cost and low risk. No needles, no downtime, no hospital stay.
It pays off either way. If you do need surgery someday, you go in stronger, and these same exercises are the foundation of your recovery.
Photo: Intenza Fitness on Unsplash
Why the bike is the centerpiece
Cycling builds the quadriceps and moves the knee through a smooth, repeated range of motion without the pounding of running or jumping. In the Osteoarthritis Initiative, people who had bicycled during their lives were 17% less likely to have frequent knee pain and 21% less likely to have painful X-ray arthritis than people who never biked, and the benefit grew with more years of cycling. That study shows an association, not proof, but it fits what I see in clinic.
Your first 8 weeks
Bike therapy, most days:
Use a stationary bike, or a road bike on flat, safe routes.
Set the seat high enough that your knee is almost straight, with a slight bend, at the bottom of the pedal stroke. A seat that is too low bends the knee too far and can aggravate pain.
Start with light resistance for 10 minutes. Build to 20 to 30 minutes.
Strengthening, 2 to 3 days a week (2 to 3 sets of 10 to 15 repetitions):
Straight-leg raises and quad sets
Sit-to-stand from a chair, without using your hands if you can
Step-ups on a low step
Partial squats or wall sits, staying in a comfortable range
Hip and glute work: side-lying leg raises, band walks and bridges
Hamstring curls
A simple pain rule: mild discomfort during exercise is acceptable if it settles by the next day. If your knee is more swollen or more painful the next morning, ease back and build up more slowly.
Track your progress: check your knee score now and again at 8 weeks with our KOOS knee score calculator. Our physical therapy partners, listed on the PT locations page, can coach you through it.
Ready to start?
Not every knee avoids surgery, but every knee benefits from being stronger. Book a visit and we’ll tailor the program to your knee and decide together on the next step. Please come in sooner if your knee locks, gives way, swells suddenly or wakes you at night.
References
Culvenor AG, et al. Knee extensor strength and risk of structural, symptomatic, and functional decline in knee osteoarthritis: a systematic review and meta-analysis. Arthritis Care Res. 2017.
This article is for general education and isn’t medical advice. For advice about your own condition, please book a visit.