Weak Quads and Knee Pain: What the Research Says
If your knees ache after hiking, golf or a long day on your feet, the muscles on the front of your thigh deserve a look. Your quadriceps absorb most of the load every time you take a step, climb stairs or stand up from a chair. When they are weak, the knee joint takes on more of that work.
Many active adults in their 40s, 50s and 60s respond to knee pain by resting, backing off their activity or assuming it is an unavoidable part of getting older. There is good reason to question that approach, because the research increasingly connects quadriceps strength to how the knee feels over time.
What a 2025 study found about quad power and knee pain
A 2025 study in The Journal of Rheumatology followed adults who had or were at risk for knee osteoarthritis for 2 years. Knee osteoarthritis is the gradual wearing of the joint surfaces, and it is one of the most common sources of knee pain in adults over 40.
The researchers measured knee extensor power, which is how quickly the quadriceps can produce force. People in the weakest quarter had about 1.95 times the odds of developing frequent knee pain, defined as pain on most days of the month. Their pain also tended to worsen more over the 2 years, although that particular result was less certain statistically. The authors suggest that training knee extensor power may help reduce new and worsening knee pain.
What the longer-term evidence shows
A 2022 systematic review in the British Journal of Sports Medicine pooled 11 studies and more than 46,000 people. It found that weak knee extensors were linked to higher odds of developing painful knee osteoarthritis, with the association somewhat stronger in women than in men.
The evidence quality in that review was rated low, so it shows a link rather than proof that weak quads cause knee problems. The pattern across studies is consistent, however, and it fits what I see in the clinic every week.
Why the hips matter too
Quad strength is only part of the picture. A 2023 review of 14 studies in the Journal of Back and Musculoskeletal Rehabilitation looked at adults with pain around the kneecap. Hip strengthening improved pain and function in all 14. In 4 of the 5 trials that compared quad work alone with quad and hip work combined, the combined approach did better.
This is why I treat the whole chain from the hip to the foot rather than only the spot that hurts. A knee that is overloaded is often being asked to make up for something happening above or below it.
What this means for you
A knee that hurts is not a knee that should be rested indefinitely. Building strength in the quads and hips, in the right amounts and at the right pace, is one of the best-supported ways to keep the knee working and keep you doing what you enjoy.
The right starting point depends on why your knee is irritated in the first place. This is why I begin by finding the source and calming it down with hands-on treatment, then load the knee progressively so the strength you build holds up under the activities you care about. Jumping straight into a generic leg routine can aggravate a knee that is not ready for it.
Schedule a visit
If your knees have been holding you back, you do not have to wait it out or live around it. You can schedule a visit and I will find the source and build a plan in order to get you moving the way you want.
Dr. Doug Ashton, DPT, FAAOMPT
Owner, Enhance Physical Therapy
References
Huang C-H, Segal NA, Felson DT, et al. Effect of Knee Extensor Power on Knee Pain in Adults With or at Risk for Osteoarthritis: The Multicenter Osteoarthritis Study. The Journal of Rheumatology. 2025;52(12):1281-1287. https://www.jrheum.org/content/52/12/1281
Øiestad BE, Juhl CB, Culvenor AG, Berg B, Thorlund JB. Knee extensor muscle weakness is a risk factor for the development of knee osteoarthritis: an updated systematic review and meta-analysis including 46,819 men and women. British Journal of Sports Medicine. 2022;56(6):349-355. https://bjsm.bmj.com/content/56/6/349
Alammari A, Spence N, Narayan A, Karnad SD, Ottayil ZC. Effect of hip abductor and lateral rotator strengthening on pain and function in adults with patellofemoral pain: a systematic review and meta-analysis. Journal of Back and Musculoskeletal Rehabilitation. 2023;36(1):35-60. https://salford-repository.worktribe.com/output/1325167
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