6 Reasons Why Your Knees Are Stiff & How to Loosen Them
Medically reviewed by: David M. Joyner, MD, FACS
Knee pain and stiffness are common among adults. While joint discomfort, reduced range of motion, and other mobility issues are more likely to happen in the later seasons of life, stiff knees can happen at any age for a number of reasons.
Knowing what to do for stiff knees starts with figuring out why they're stiff. Let's go over the possible explanations for a stiff knee—like osteoarthritis, tight muscles, inactivity, or poor circulation—and practical tips to loosen them up.
Why Knee Stiffness Happens in the First Place
Knee stiffness can happen over time as part of the natural wear-and-tear process the body goes through with age. Other factors can also contribute to knee issues, including injuries, carrying excess body weight, and lifestyle habits—we'll go over these in more detail below.
Whatever the underlying cause, knee stiffness crops up when supportive tissue and muscle wear down or deteriorate.
The Role of Joints, Muscles, and Circulation
The supportive tissue (called cartilage) around the knees cushions the joints. When it becomes thin, you might notice stiffness and reduced range of motion.
Adults in their 40s, 50s, 60s, and beyond (especially women) may not have as much muscle mass as they once did. This reduced strength can make it less comfortable to walk around, go from a standing position to sitting, get out of bed, and stand for long periods.
Another issue can be poor circulation. Improper blood flow throughout the body may contribute to inflamed joints, potentially accompanied by stiffness, pain, swelling, or mobility issues.
When Stiffness Is Normal—and When It's Not
If your knee feels stiff once in a while, it may not be a cause for concern—it can happen to the best of us. But when the problem happens more than occasionally, it might point to an underlying condition (such as osteoarthritis) or a health issue that needs addressing, like obesity or a sedentary lifestyle.
6 Common Causes of Stiff, Achy Knees
Why are my knees stiff? You're not the first person to wonder (or Google) this.
If you're experiencing chronically stiff knees, check in with a healthcare provider to get to the root of the issue. Having said that, these are some of the most common culprits:
- Lack of physical activity
- Osteoarthritis or aging joints
- Tight hamstrings or quadriceps
- Poor circulation
- Past injuries or overuse
- Improper warm-ups or form with exercise
Here's what to know.
#1 Lack of Physical Activity
A sedentary lifestyle means you get very little physical activity each day. Making time to exercise is part of the solution, but it might not be enough to offset the rest of your day. For example, even if you work out for an hour each morning, you'll still want to avoid sitting for several hours in a row (as with a desk job) because this can contribute to joint stiffness and weakened muscles.
Beyond working out at least a few days a week, try to move more each day. This might include standing up and walking around your home or office every hour or so, playing with your kids, walking around while taking phone calls, cleaning your home, or running errands.
#2 Osteoarthritis or Aging Joints
Osteoarthritis is a top cause of knee pain and stiffness. It's a degenerative disease, meaning it happens slowly and worsens over time due to natural wear and tear on cartilage (which happens with age but can be sped up with overuse or from carrying excess body weight). This can restrict movement and make it harder (or painful) to move your limbs in a complete range of motion.,
#3 Tight Hamstrings or Quadriceps
Tight or imbalanced muscles—especially those supporting the knees, like the quads and hamstrings—can make your knees feel stiff. This could be due to standing for long periods, working a physically demanding job, doing a particularly tough workout, or even something like gardening that calls for crouching down for hours.
#4 Poor Circulation
Circulation issues can also leave you with stiff, achy knees. Without proper blood flow in the body, your joints may not move as smoothly as they should, leading to tight muscles and discomfort in your legs.
Lots of things can limit circulation, including not getting enough general movement or obesity. Our blog has tips for building muscle and losing fat.
#5 Past Injuries or Overuse
A previous injury, past surgery, or muscle strain in the lower body (such as a strained calf or sprained ankle) can result in scar tissue formation or a muscle imbalance that puts extra pressure on the knee, causing inflammation and stiffness.
This can also happen from overuse, meaning repetitive movements put stress on the joint—something that can happen to runners and people with physical jobs, like construction workers.
#6 Improper Warm-Ups, Form, or Posture
Diving straight into a hard workout without warming up first can increase your risk of injury, restrict joint movement, and impact your ability to properly perform each move. Starting with dynamic stretches that involve a full range of motion (like arm swings, alternating toe taps, or marching in place) will increase circulation, sending blood and oxygen to your arms and legs to prevent strain and stiffness.
Performing each move with the right form and posture is also key to avoiding joint issues. For instance, a common mistake when doing squats is not keeping the knees in line with the ankles. When the knees go too far forward, it can put too much pressure on the joints and lead to pain, stiffness, or injury.
How to Loosen Up Stiff Knees Naturally
If you're wondering how to get rid of stiff knees to become more mobile and all-around comfortable, the best approach involves frequent movement, improving flexibility, building strength, and using heat and Whole Body Vibration..
Stay Active With Low-Impact Movement
Staying active can go a long way in keeping knee stiffness at bay. Rather than high-intensity workouts that stress the joints, try low-impact movement, such as walking, cycling, swimming, step aerobics, or Whole Body Vibration.
Stretch and Strengthen Supporting Muscles
Focus on building strength in your lower body, particularly muscles supporting your knees, like your hamstrings, quads, hips, and glutes. Simple bodyweight exercises can be really beneficial here—think deadlifts, squats, calf raises, or reverse lunges. A few minutes of daily stretching can be beneficial as well.
Another way to boost lower-body strength and balance is with whole-body vibration. Standing on a vibration plate has been shown to improve knee-extension strength. This means the quads are strong enough to support a fully extended knee (straightened leg).
Improve Circulation to the Knee Joint
Good circulation is crucial for keeping joints lubricated, reducing inflammation, and staving off stiff knees. Regular movement (including exercise and more day-to-day general activity) can help enhance blood flow.
Whole Body Vibration is also highly effective for increasing blood circulation. Using a vibration plate can support flexibility while helping muscles relax and contract—all vital for preventing stiffness.
Apply Heat and Do Movement Therapy
If you're currently experiencing stiffness and looking for a remedy, applying heat (with a rice pack, hot water bottle, steamed towel, or heating pad) can help relax stiff muscles and restore joint movement in the knees.
This can pair well with light physical activity, such as standing on a vibration plate, to loosen things up and regain full mobility.
Why Power Plate Is Ideal for Stiff Knees
Power Plate's whole-body vibration platforms are backed by science. The joint-friendly designs are easy to use yet extremely effective at minimizing stiffness, building strength, and promoting better knee health.
Whole Body Vibration:
- Stimulates circulation and promotes mobility – With up to 50 vibrations per second, a vibration plate can increase blood circulation, promote better flexibility, relieve stiffness, and encourage full-body mobility.
- Engages muscles without joint impact – Our patented PrecisionWave technology uses multidirectional vibration to activate several muscles at once, building strength, balance, and bone density—all with minimal impact on the joints.,
- Is easy to do at home – A compact, user-friendly Power Plate can be placed anywhere in your home, moved around as needed, and used any day of the year, rain or shine. Designed to maximize results in as little time as possible, you can do a complete workout in just 15 minutes.
For more on the benefits of Power Plate for joints, see our guide to vibration plates for arthritis.
Explore Power Plate's Whole-Body Vibration Collection
A vibration plate from Power Plate is a solid choice for anyone experiencing knee pain, stiffness, or joint discomfort. Our vibrational platforms offer low-impact activity that's easy on the joints but still builds muscle, improves bone density, boosts circulation, and helps with recovery.
You can also explore our targeted vibration devices. This includes percussive therapy massage guns, concentrated massagers, and vibrating foam rollers.
Learn more about how Power Plate can help you build muscle and regenerate cartilage without hurting your joints.
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