Does cracking your knuckles cause arthritis and will running really ruin your knees? Experts separate fact from fiction

MOST of us don’t give our joints much thought – but our bodies have around 350 of them, and they’re pretty important.

From the tiny ones in our toes to our shoulders, hips and knees, our joints keep us moving – whether we’re walking, running, or simply bending down to tie our laces. 

Unfortunately, if we don’t look after them properly, they can cause serious issues as we age.

Dr Wendy Holden, consultant rheumatologist and medical adviser to Arthritis Action, tells Sun Health: “It can lead to stiffness, aches and even arthritis – a common condition that causes pain and inflammation in a joint.”

You can care for your joints by eating a balanced diet full of lettuce, broccoli, spinach and kale, all of which slow down cartilage destruction and lessen the amount of bone loss that occurs with age, according to the Arthritis Foundation.

Staying active, quitting smoking, keeping your weight in the healthy range, eating plenty of calcium, and daily stretching are also vital.

Even avoiding high heels, which put extra stress on your knees, can be beneficial, experts say. 

But beware of joint-related myths that could be stopping you from giving yours the TLC they deserve.

Here, we asked experts to separate fact from fiction… 

1. Cracking knuckles cause arthritis – FICTION 

WHETHER it’s a force of habit or a way to de-stress, the sound of knuckles cracking doesn’t sound particularly healthy.

But Dr Holden says that cracking your knuckles doesn’t actually damage them or cause arthritis. 

“The ‘crack’ sound comes from tiny gas bubbles in the fluid inside your joints and, on the whole, it’s harmless,” she says.

“However, if your knuckles start to hurt, swell, or feel weak, it’s best to get them checked. 

“Some people have reported that cracking their knuckles makes their hands feel looser, but it’s really just a habit.”

So, if you enjoy it, crack on!

2. Phone addictions destroy joints – FACT 

IF you spend hours hunched over your phone, your neck may well pay the price.  

“Many of us, and particularly young people, are storing up a lifetime of neck and back pain because of poor posture, which is directly linked to over-use of electronic-based technology, such as smartphones,” says Michael Fatica, lead osteopath and co-founder of Back In Shape Program.

According to him, the neck should have a smooth backward bending ‘C’ shape curve.

“But so many of us have our necks buckled over forwards, bent over in completely the wrong direction for extended periods of time,” he adds.

“When this is done repeatedly, the neck will change shape. 

“It’s only a matter of time before people start getting stiffness and tension in the shoulders and back of the neck.”

Watching hours of back-to-back TV episodes in bed, with your head propped up, can also cause extreme and persistent stress and inflammation on the spine and neck, Michael warns. 

“The lower back, too, is affected by prolonged poor posture, which can make recovery from slipped or bulging discs and sciatica even more difficult,” he says.

The best way to maintain healthy joints is to eat plenty of protein, stay active and keep a healthy weight. There’s no need to spend a fortune on special supplements

Dr Wendy HoldenConsultant rheumatologist

To help, try what’s known as the ‘towel stretch’. 

Lie on the floor with your knees bent and place a small towel, rolled tightly, under the neck. Then let your head drop over the towel. 

If you’ve got a tight lower back, Michael recommends lying straight across your bed on your tummy with your armpits lined up with the edge of the bed, and your arms dangling down.

“Then use your upper arms against the side of the bed to gently stretch your lower back for approximately 20 seconds,” he says.

“This is a really effective way to decompress your spine.”

3. Collagen supplements can rebuild joints – FICTION

THE wellness scene is awash with collagen powders, drinks, gels and gummies, which supposedly help to support your bones, skin, muscles and joints. 

Are they worth it though? According to research, the jury is still out.

While a 2023 study published in the Journal of Orthopaedic Surgery and Research found that collagen peptides could potentially provide pain relief for those with knee osteoarthritis compared to a placebo, other research in the Journal Rheumatology and Therapy found that in three out of four studies, collagen hydrolysate was either ineffective or detrimental to bone cartilage.

Dr Holden explains that collagen is a protein that forms part of your cartilage, bones, tendons and ligaments. 

“Your body already produces collagen,” she says.

“The best way to maintain healthy joints is to eat plenty of protein, stay active and keep a healthy weight. 

“There’s no need to spend a fortune on special collagen supplements.”

4. Running makes joints worse – BOTH

IF you’re regularly pounding pavements, you might wonder how the joints in your lower body are holding up. 

Well, according to Dr Holden, regular running can help keep joints strong, so long as you do it right. 

“The problem comes when people overdo it, wear the wrong shoes or consistently run on hard surfaces,” she says.

New to running? Start slow and invest in proper, well-fitted trainers. 

Adding strength exercises can protect your knees long-term. Try squats, lunges and if you’re a gym member, give the leg press a try.

“The ‘step-up’ is also a great exercise for stability, by helping us to build muscle and integrity in the legs, which will help protect us against, for example, arthritic change,” says Michael. 

Find a bench and step up slowly with your right leg, letting your left leg follow. 

Slowly step down then repeat on the other side. Keep alternating, doing 10 reps on each side. 

“It’s also smart to mix up your exercise – try swimming or cycling to give your joints a break,” Dr Holden says.

“If your knees ever feel sore, take a rest day and try some gentle stretching instead.”

5. Omega-3 supplements are good for joints – FACT 

WHILE omega-3 fatty acids are good for your heart and brain, they’re also brilliant for joint health too, according to Dr Holden. 

Research published in the Journal of Orthopaedic Surgery and Research found that supplementing with omega-3 could significantly relieve arthritic pain compared to a placebo, as well as improve joint function.

“There are no national daily requirements for omega-3 set out in the UK, but the recommended amount is 450 milligrams (mg) per day,” Dr Holden, a specialist in bone health, osteoporosis, fracture prevention, osteoarthritis and pain management at Curaleaf Clinic, says.

“Many people can get this through eating a diverse diet containing oily fish – such as sardines, salmon and mackerel, as well as nuts and seeds. 

“Others may need to take a supplement.”

6. Having a sedentary lifestyle wrecks your joints – FACT

MANY British adults spend around nine hours a day sitting down, according to the NHS. 

But spending too long on your bottom can have a negative impact on your joints as you simply aren’t using them enough.

“Being too sedentary weakens the muscles and causes us to perform movements – and develop bad habits – which do not move the joints to their full range of motion,” Michael says.

“For example, if you imagine someone who spends their entire day sitting down, they will hardly ever bend their knees past 90 degrees and they will hardly ever straighten their hips into a fully upright position – they will always be ‘curled up’.”

By not moving joints through a full range of motion – meaning the full range of movement a joint is capable of doing – you aren’t coating the surface of your joints in synovial fluid. 

This is the fluid of the joint which provides it with nutrition. 

“As a result, joints become ‘rusty’ so, in turn, we move them less as it becomes too painful,” Michael says.

“This naturally causes them to become even ‘rustier’, so we move them even less and become even more sedentary.

“A minor strain may become difficult to recover from because of the poor health of the joint and surrounding tissues. 

“Being fidgety can help with this problem, such as repositioning yourself in your seat or getting up at regular intervals to walk around – anything that gets the body out of one set position.”