Knee pain is rarely a straight-forward problem to figure out. With so many important structures packed into such a small space, it can be difficult to guess exactly what’s causing your knee pain, without visiting a doctor.

TOP OF KNEE
Quadriceps Tendinopathy
INSIDE OF KNEE
Medial Collateral Ligament (MCL) injury
Groin muscle tendonitis
Medial meniscus injury
KNEE CAP AREA
Condromalacia (Runners Knee)
Patella Tracking
OUTSIDE OF KNEE
Illitobial band friction syndrome
Lateral Collateral Ligament (LCL) injury
Lateral Meniscus tear
BELOW KNEE
Patellar tendonitis (Jumpers Knee)
While in no way exhaustive, we’ve created this easy-to-understand chart that can help you understand the possible reasons why you’re experiencing knee pain.
Please keep in mind that the knee is an incredibly complex system of many different components, and that their close proximity to one another can make it very hard to understand where the pain is coming from without professional diagnosis.
Top of Knee
Quadriceps Tendonitis
The quadriceps tendon connects the quadriceps muscles in the front of the thigh to the top of the kneecap. Tendinopathy is a common overuse injury caused by repeated and prolonged stress on a tendon. This repeated stress (micro-trauma) on the tendon can lead to the tendon becoming thickened and tiny tears developing in the tendon. The body attempts to repair these tiny tears, but if the rate of breakdown within the tendon exceeds the rate of repair, this can lead to pain and dysfunction.
A quadriceps tendon issue will usually feel sore to the touch. Heat and burning may accompany the injury, and knee pain concentrated on the top of the knee cap will feel stiff in the morning.
INSIDE OF KNEE
Medial Collateral Ligament (MCL) injury
MCL injuries (tears) are common in athletes, especially those who play sports that require a lot of twisting, turning and fast changes of direction. The medial collateral ligament (MCL) is located on the inner side of your knee, and it’s eight to 10 centimeters in length. It connects your thigh bone (femur) to your shin bone (tibia). Your MCL also provides strength and stability to your knee joint.
If the medial collateral ligament has been damaged or torn, you will usually have:
- Pain, which can range from mild to severe
- Stiffness
- Swelling
- Tenderness along the inside of the knee
- A feeling that the injured knee may give way under stress or may lock or catch
Groin muscle tendonitis
It seems odd that your groin muscle could cause knee pain, but the lowest and longest of the groin (adductor) muscles connect to the inside of your knee. This type of injury is common to runners and skiers.
Tendonitis in the groin muscle will cause radiating heat and pain and soreness to the touch. Many people will experience more severe knee pain and stiffness in the morning, after waking up.
Medial meniscus tear
The menisci — the medial meniscus and lateral meniscus – are crescent-shaped bands of thick, rubbery cartilage attached to the shinbone (tibia). They act as shock absorbers and stabilize the knee.
In sports, a meniscus tear usually happens suddenly. Severe pain and swelling may occur up to 24 hours afterward. Walking can become difficult. Additional pain may be felt when flexing or twisting the knee. A loose piece of cartilage can get stuck in the joint, causing the knee to temporarily lock, preventing full extension of the leg.
If you have a torn meniscus, you may:
- Be unable to extend your leg comfortably and may feel better when your knee is bent (flexed).
- Develop pain gradually along the meniscus and joint line when you put stress on your knees (usually during a repeated activity). This most often happens when the tear develops over a period of time.
- Have swelling, stiffness or tightness in your knee.
KNEE CAP AREA
Condromalacia (Runners Knee)
Runner’s knee, also known as patellofemoral pain (PFP), means that you have pain in front of the knee or around the kneecap (patella). This is where the knee connects with the lower end of the thighbone (femur).
The most common symptoms of runner’s knee are:
- Pain in and around the kneecap that happens when you are active.
- Pain after sitting for a long time with the knees bent. This sometimes causes weakness or feelings of instability.
- Rubbing, grinding, or clicking sound of the kneecap that you hear or feel when you bend and straighten your knee
- Kneecap that is tender to the touch
Patella Tracking
Patellar tracking disorder is a condition where the kneecap moves out of place when the leg straightens or bends. In most cases of patellar tracking disorder, the kneecap moves to the outside of the leg, but there are cases where the kneecap moves toward the inside of the leg.
Patellar tracking disorder usually has the following symptoms of knee pain:
- Feeling like your kneecap is popping, slipping, clicking, or catching when you bend or straighten your leg
- Pain in the front of your knee during physical activity, especially when squatting or going down stairs
- The feeling that your knee cannot support your weight
OUTSIDE OF KNEE
Illitobial Band Syndrome (IT Band Syndrome)
The “IT band” is a long, fibrous band of flexible fascia that extends from the hip to just below the outside of the knee. It also has an attachment to the outside of your knee cap. IT band syndrome is a common overuse injury, causing pain at the outside of the knee. It is typically seen in runners and cyclists.
The most common knee pain symptoms of IT band syndrome are:
- pain located on the outside of the knee that increases as a person runs, cycles or performs other exercises that involve repetitive bending and straightening of the knee.
- a feeling of clicking, popping or snapping on the outside of the knee.
Lateral Collateral Ligament (LCL) injury
An LCL injury (a torn LCL or a LCL tear) is a strain or tear to the lateral collateral ligament (LCL). The LCL is a band of tissue that runs along the outer side of your knee. It helps to hold the bones together so that your knee joint remains stable when you move.
LCL injuries are generally caused by a blow to the inside of the knee (such as being kicked while playing soccer, or a low football tackle), or a too-abrupt change of direction. Landing awkwardly while jumping can also cause an LCL tear.
If you hurt your LCL, it’s common to:
- feel stiff, sore, or tender along the outer edge of your knee.
- Your knee may feel like it could give out when you’re walking or standing.
- Your knee may lock in place or catch when you walk, instead of moving smoothly.
- You may not have your normal range of motion.
- Your foot may feel numb or weak, along with your knee pain, if it’s a severe tear.
- You may have bruising on or around the knee.
Lateral Meniscus Tear
As with any meniscus tear, lateral meniscus tears occur suddenly. You will know a specific time when your injury occurred. Symptoms are:
- Sudden severe knee pain at the time of injury.
- The outside surface of your knee will feel tender when pressing in, particularly along the joint line.
- Your knee is likely to swell up either immediately, or within 24 to 48 hours.
BELOW KNEE
Patellar tendonitis (Jumpers Knee)
The patellar tendon connects the bottom of the kneecap (patella) to the top of the shinbone (tibia). Despite its name, the patellar tendon is actually a ligament. Tendons connect a muscle to a bone. Ligaments connect two muscles.
The patellar tendon provides stability, holding bones together. It also works in tandem with the quadriceps (thigh) muscle and other connective tissues to help you move. You couldn’t straighten your knee or jump without it.
Patellar tendonitis happens when the patellar tendon tissue becomes inflamed (swollen) or irritated. Overuse usually causes this knee injury.
Symptoms of patellar tendinitis include:
- Pain or dull ache at the top of the shinbone, right under the kneecap.
- Stiffness, which may make it hard to extend the knee.
- Worsening pain with certain movements, such as when you squat or walk down stairs.
What to do if you experience knee pain
Make an appointment with an orthopedic surgeon! Do not take the risk of your injury becoming worse or even permanent. It is vitally important that you receive timely medical treatment with several of the injuries listed here. Tendon, ligament and meniscus tears are unlikely to heal properly on their own, without a treatment plan in place. Ignoring these injuries, ‘playing through the pain’, can lead to life-long complications and invite several more life-altering injuries further down the road, such as osteoarthritis.
While you’re waiting for your doctor’s appointment, be sure to follow the RICE protocol, to rest, ice, compress and elevate your affected limb.
At Dayton Orthopedic Surgery, we have decades of experience healing every type of knee pain imaginable! Call (937) 436-5763 to schedule an appointment with a knee pain expert.