ARE your knees niggly, aching or sore? After the back, our knee joints are the most common site for musculoskeletal pain, with the HSE estimating that more than 400,000 people are affected by osteoarthritis, and it mainly affects the knees.
Global studies show that one in five adults experiences knee problems at some point in their lives and it only gets worse as we age. One in five women and one in 10 men in Ireland over the age of 60 are diagnosed with joint pain, often in the knees.
But do we know enough to keep our knees in good shape? Here, we scour the latest evidence and speak to experts about how to keep our knee joints in tip-top condition.
Should I avoid squats if I have dodgy knees?
A decade or so ago, anyone prone to knee pain might well have been advised to rest and to avoid exercises that put undue strain on the knee joint, such as squats. That has changed, and squats are now among the exercises often recommended to improve strength in the muscles around the knees, including the quads, hamstrings, calves, and hips, and to enhance range of movement.
Squats are also a common feature in rehab routines after knee injuries, although you should never dive straight into doing deep squats or squats with heavy weights.
Joey Boland, a sports physiotherapist at SportsPhysio Ireland in Dublin, says a carefully planned knee pain recovery pathway is critical to reduce pain as you gain strength. In phase one of recovery, you need to build strength in the quadriceps muscles at the front of the thighs, which act as shock absorbers for the knees and also help improve stability.
“It is important the quadriceps get stronger, but without causing pain,” he says.
“When ready, you can gradually move to [phase two] by increasing the strength such as wall sits prior to attempting squats, and only when you are ready do you start phase three, which is dynamic movement such as split squats to build robust strength in the knees.”
These exercises should be under the guidance of a registered physiotherapist, Boland says.
What supplements should I take to keep my knees in good shape?
An array of supplements — from glucosamine and chondroitin sulphate to collagen and turmeric — claim to relieve and prevent knee and joint pain, but there’s little evidence that they have a direct effect on the knee joint or that they work at all.
A review of studies involving 4,000 people published in Archives of Orthopaedic and Trauma Surgery found that glucosamine and chondroitin supplements had little or no effect on relieving osteoarthritis knee pain.
And while curcumin, the active ingredient in turmeric, has anti-inflammatory properties, not enough is yet known about its effect on joints. People with low levels of vitamin D, the best source of which is sunshine, have been shown in some studies to be more susceptible to joint pain, so correcting a shortfall might be beneficial.
A 2024 study in Scientific Reports on men with knee osteoarthritis showed that those with higher vitamin D levels had lower pain scores. Similarly, a deficiency of vitamin K, found in leafy greens, prunes, and Kiwi fruit, has been associated with higher incidences of knee problems in some studies.
Is running a sure-fire route to bad knees?
Because it is a high-impact activity, running has a reputation for being a knee-wrecker. However, while it loads the knees more than walking, for example, it may also strengthen the supporting muscles and fortify cartilage, according to a study in the journal PeerJ.
It’s never too late to start. In a study carried out by Alister Hart, a British orthopaedic surgeon, it was shown that even among beginners, regular distance running can help to improve middle-aged knee health. This was true even if scans taken before they took up running showed their knees were in bad shape with damaged or torn cartilage or lesions in the bone marrow. After four months of marathon training, the first-timers had strengthened and stabilised muscles around their knees, helping to reverse some of the tissue damage.
“It seems that better blood supply and stress responses from running lead to these positive changes in the knee joint,” Hart says.
Other studies have shown that inflammatory molecules in the knee joint decrease after running, reducing inflammation around the joint. However, common sense should prevail. “If starting out, you should always proceed with caution as too many miles too quickly is not a recipe for healthy joints,” Hart says. “And if you have had a serious knee injury that causes ongoing instability or causes the knee to give way, then running is probably not for you.”
My knees start to ache after going to the gym or running — is that a bad sign?
Some aching in the muscles around the knee after a workout is normal, however if pain is acute and severe you need medical attention. If the discomfort is more of an ache that develops over time, you need to monitor it.
“If you did your usual amount or up to 10% more gym work or run distance session compared to the previous week then it is very unlikely that the knee discomfort is a problem,” Hart says. “But if you added any new exercises or if you increased weights or the intensity of a run or session by quite a bit, then you probably need to rest for up to 48 hours and apply ice for up to 10 minutes at a time, as some minor muscle damage will have occurred.”
Restart with light exercises and gradually progress in intensity, duration, and frequency, no more than about 10% per week. If the discomfort persists, you will need to see a physiotherapist for advice.
Is walking enough to keep knees healthy?
Keeping up your daily steps is a fundamental part of good knee health, helping to keep joints, muscles, and tendons in shape. Walking helps the knees, even if you have early stage osteoarthritis, although you will need to build up gradually and take advice from a specialist if you experience significant pain when moving.
For those who don’t, Grace Hsiao-Wei Lo, assistant professor of immunology, allergy, and rheumatology at Baylor College of Medicine, Texas, found that middle-aged and older people who walk for exercise had less new knee pain than non-walkers.
She also suggested that walking could help slow the progression of knee damage from osteoarthritis.
“People diagnosed with knee osteoarthritis should walk for exercise, particularly if they do not have daily knee pain,” Lo said. “If you already have daily knee pain, there still might be a benefit, especially if you have the kind of arthritis where your knees are bow-legged.”
I ruptured my ACL playing sport — do I need to go under the knife?
Injuries to the anterior cruciate ligament (ACL), a tough band of tissue that connects the thigh to the shin bone at the knee joint to provide stability, are common in sports that require sudden changes in direction, such as skiing, football, tennis, and squash. But even if you tear the ACL completely, you might not need to go under the knife, and it is something to discuss with your surgeon. Much depends on whether there is damage to other parts of the knee, if you want to play sports that involve a lot of twisting or if you have a physcially demanding job.
In many cases, returning to forward-motion-only sports, such as cycling, walking, and running, is possible after a period of rehabilitation, even without surgery. A 2022 study found that ACL surgery had no protective effect against future knee osteoarthritis and that “a significant improvement in knee function could be achieved” with carefully structured exercise just as well as with surgery.
