Runners, jumpers, and other athletes such as skiers, cyclists, and soccer players put heavy stress on their knees. Runner’s knee is a term used to refer to a number of medical conditions that cause pain around the front of the knee (patellofemoral pain). These conditions include anterior knee pain syndrome, patellofemoral malalignment, and chondromalacia patella.
Symptoms
A dull, aching pain under or around the front of the kneecap (patella) where it connects with the lower end of the thighbone (femur). Pain occurs when walking up or down stairs, kneeling, squatting, and sitting with a bent knee for a long period of time.
Causes
The knee is a complex structure and is very sensitive. A number of factors can contribute to runner’s knee, including:
- Malalignment of the kneecap
- Complete or partial dislocation
- Injury
- Excessive training or overuse
- Tightness, imbalance, or weakness of thigh muscles
- Flatfeet
Patellofemoral pain may be the result of irritation of the soft tissues around the front of the knee. Strained tendons are fairly common in athletes. Other contributing factors to patellofemoral pain include overuse, muscle imbalance and inadequate stretching. Pain that begins in another part of the body, such as the back or hip, may cause pain in the knee (referred pain).
In some people with runner’s knee, the kneecap is out of alignment. If so, vigorous activities can cause excessive stress and wear on the cartilage of the kneecap. This can lead to softening and breakdown of the cartilage on the patella (chondromalacia patella) and cause pain in the underlying bone and irritation of the joint lining.
Prevention
- Stay in shape.Good general conditioning is important to controlling and preventing patellofemoral pain. If you’re too heavy, you may need to lose weight to avoid overstressing your knees.
- Stretch.Before running or any other exercise, first do a 5-minute warm up, followed by stretching exercises. Stretching, particularly in the face down position (prone), will help keep the supporting structures around the front of the knee flexible and less likely to be irritated with exercise. For example, when lying prone, grab the ankle of the affected leg with one hand, and gently stretch the front of the knee. Stretch before and after exercise.
- Increase training gradually.Avoid sudden changes in the intensity of exercise. Increase force or duration of activities gradually.
- Use proper running gear.Use running shoes with good shock absorption and quality construction. Be sure that shoes fit properly and are in good condition. If you have flat feet, you may need shoe inserts.
- Use proper running form.Lean forward and keep your knees bent. Also, try to run on a clear, smooth, resilient, even, and reasonably soft surface. Never run straight down a steep hill. Walk down it, or run in a zigzag pattern.
Diagnosis
Medical History
Your doctor will take a complete medical history and inquire about your symptoms. Tell your doctor about any sports participation or training you are involved in, and which activities aggravate your knee pain. Have there been any recent changes to the duration, frequency, or intensity of your activities? Any changes to the surfaces you run or play upon?
Physical Examination
Your doctor will perform a physical examination on your knee to help determine the cause of pain.
To assess your knee’s strength, mobility and alignment, the doctor may ask you to stand, walk, jump, squat, sit, and lie down.
The physical examination will include a check of the alignment of your lower leg, kneecap, and quadri