Knee pain is an extremely common ailment, with pain levels ranging from mildly annoying to severe and debilitating. Knee pain causes are just as varied: excess weight, injury, illness, etc… Regardless, a knee pain diagnosis is useless without knowing what caused it, how to fix it, and how to prevent future knee pain. Your knee joint is actually fairly complex (1). Bones of the knee include:
- tibia and fibula (lower leg bones)
- patella (kneecap)
- femur (upper leg bone)
- meniscus (acts as a shock absorber) the menisci are found on the ends of the femur and tibia and at the back of the patella
- prepatellar bursa
- medial collateral ligament Bursa
- iliotibial Bursa
- suprapatellar bursa
- gastrocnemius-semimembranosus Bursa
- infrapatellar bursae
- pes anserine bursa
Tendons and ligaments of the knee:
- anterior cruciate ligament (ACL)
- posterior cruciate ligament (PCL)
- medial collateral ligament (MCL)
- lateral collateral ligament (LCL)
- quadriceps tendon
- patellar tendon
Any bone or soft tissue of the knee can be injured or affected by certain medical conditions. Symptoms of knee problems include knee joint pain (sharp or dull), swelling, general soreness, difficulty bending or straightening the leg, and even hip or foot pain.
11 Worst Knee Pain Causes
Thankfully, you can reverse most of these knee pain causes naturally.
This is one of the most common knee pain causes by far. Given how complex the knee is, there are almost countless ways in which a knee can be injured.
In sports, we often hear of a torn tendons, ligaments, or meniscus, knee sprains, hyperextensions, and more. Dislocations and breaks are less common but very serious.
In these cases, knee pain relief is usually provided through a combination of rest, physical therapy, ice, immobilization, and/or surgery. More severe injuries may limit future knee movement, strength, and mobility.
Make sure to give yourself ample time to recover from an injury– returning to physical activity before you are fully healed can extend recovery time and may cause permanent damage (4).
2. Mechanical Problems
Mechanical knee pain accounts for a significant amount of knee injuries and is usually associated with physical activity (5). One of the most common of which is iliotibial (IT) band syndrome. Your IT band is a band of tough tissue (similar to a tendon) that runs from right above your hip to just below the knee joint (6).
IT band syndrome is very common in distance runners and cyclists and occurs when the IT band tightens and rubs against the femur during activity. This can cause pain in the hip, knee, and the outer portion of the upper leg. Treatment usually includes rest, ice, and heat, moderate foam rolling, and stretching.
Other mechanical knee problems include
- dislocations of the knee (usually the kneecap)
- a loose body: a piece of bone or cartilage that has broken off and floats around the knee joint
- compensation for hip or foot pain: Hip or foot pain can make you limp, which changes the way you walk. This causes stress on your knee joint, which can result in inflammation and swelling.
Arthritis is a very general term for pain, inflammation, and swelling in the joints (7). Of all the knee pain causes out there, this is the most common amongst older adults. Knee arthritis is a very painful (usually chronic) condition as it’s hard to give your knees a rest without relying on a wheelchair.
While there are over 100 different types of arthritis, there are a few that tend to affect the knee joint more than others. Arthritis is generally treated with both natural and pharmaceutical anti-inflammatories, ice/heat, moderate physical activity, and surgery in severe cases.
- Osteoarthritis: the most common form of arthritis, resulting from wear and tear on the joints as we age
- Rheumatoid arthritis: an autoimmune disorder that attacks every joint in the body
- Septic arthritis: caused by an infection within the joint and usually accompanied by a fever
4. Excess Weight
According to the Arthritis Foundation, every additional pound of excess weight exerts around four additional pounds of pressure on your knee joints alone (8).
That means that 25 pounds of extra weight translates to 100 pounds of pressure on each knee. Being overweight or obese puts you at a significantly higher risk of developing knee pain and early-onset osteoarthritis of the knees (9).
5. High-Impact Exercise
High impact, or high-intensity exercise, is one of the best ways to burn calories and improve cardiovascular fitness (10). It’s also one of the easiest ways to cause or exacerbate knee pain since your joints absorb most of the impact.
If you have acute knee pain, it’s best to avoid high-impact exercises until the pain subsides. If you have chronic knee pain or are susceptible to it as a result of past injuries, you can take appropriate measures to minimize or avoid knee pain.
Pay attention to your posture and form while exercising, stretch, and wear proper footwear when you exercise.
6. Long Standing Jobs
Any job that requires constant standing, walking, kneeling, and/or lifting will eventually take its toll on your body.
These jobs include waiters, construction workers, landscapers, mechanics, plumbers, electricians, housekeepers/professional cleaners, and more… (11).
Take care of your knees by wearing supportive braces and knee pads when necessary. You’ll also want to take breaks when possible to sit and stretch. What’s more, make sure to ice your knees after work if you notice any signs of pain or swelling.
7. Lack of Flexibility
You may not think of flexibility as being important to the knee joint, but your knee works in more than just a back and forth direction.
Flexibility of the knee joint ensures more than just range of motion: it can help prevent future injuries and degeneration of the knee.
Try incorporating these flexibility exercises and stretches into your routine to improve flexibility and prevent future problems.
8. Lack of Strength
Just as with flexibility, you need to make sure your knees are strong enough to support you and prevent injury.
Lack of strength in the knees can lead to dislocations, torn ligaments and cartilage, and degeneration over time (12).
To strengthen your knee, you’ll want to focus on exercises that build leg muscles and focus on stability.
9. Baker Cyst
Also known as a popliteal cyst, a Baker cyst is caused by fluid in the knee joint protruding into the back of the knee. Baker cysts are actually very common and may be caused by any kind of inflammation in the knee, including arthritis (13).
These cysts do not always cause pain: one of the most common complaints with a Baker cyst is general tightness when straightening the leg and knee swelling.
Monitor a Baker cyst closely, as they can rupture. When this happens, the fluid from the cyst can travel into the lower muscles of the leg, causing bigger problems.
Treatment options for Baker cysts range from ice and anti-inflammatories to cortisone injections, cyst aspiration, or arthroscopic surgery.
This knee pain cause was previously mentioned in mechanical problems, but it truly warrants its own section. Dislocations can be partial or complete, may or may not involve the kneecap, and almost always involves tearing of ligaments (14).
Dislocation occurs when one or both of the lower leg bones move out of place in relation to the femur. Knee swelling and pain are instant and severe.
You must seek medical attention for a knee dislocation immediately or you risk losing the limb (or your life).
11. Bone Tumors
Tumors of the bone are rare, but the knee joint is the most common place for them to occur. Luckily, most bone tumors are benign – meaning they aren’t cancerous and won’t spread (15).
However, the development and removal of a bone tumor almost always causes permanent damage. Most often, the tumors lead to weakening and fractures of the knee bones (16). Surgical removal is necessary and may require a partial or full knee replacement.
Once you know the cause of your knee pain, you can make a plan to treat it and prevent it from happening again. Knee pain relief can be achieved through proper rest, rehabilitation, strength and flexibility training, and (last resort) medical interventions. If caught early, most knee pain can be treated with home remedies.
To avoid knee pain, try to get ahead of things with proper diet and exercise, maintaining a healthy weight, and regular strength and flexibility training.
Make sure to get help from a trainer if you hit the gym to avoid injury. It’s never too late for preventative measures!