Most people have had a minor knee problem at one
time or another. Most of the time our body movements do not cause problems, but
it's not surprising that symptoms develop from everyday wear and tear, overuse,
or injury. Knee problems and injuries most often occur during sports or
recreational activities, work-related tasks, or home projects.
knee is the largest joint in the body. The upper and lower bones of the knee
are separated by two discs (menisci). The upper leg bone (femur)
and the lower leg bones (tibia and fibula) are connected by
tendons, and muscles. The surface of the bones inside
the knee joint is covered by
articular cartilage, which absorbs shock and provides
a smooth, gliding surface for joint movement. See a picture of the
structures of the knee .
Although a knee problem is often caused by an
injury to one or more of these structures, it may have another cause. Some
people are more likely to develop knee problems than others. Many jobs, sports
and recreation activities, getting older, or having a disease such as
osteoporosis or arthritis increase your chances of
having problems with your knees.
Sudden (acute) injuries
Injuries are the most common
cause of knee problems. Sudden (acute) injuries may be caused by a direct blow
to the knee or from abnormal twisting, bending the knee, or falling on the
knee. Pain, bruising, or swelling may be severe and develop within minutes of
the injury. Nerves or blood vessels may be pinched or damaged during the
injury. The knee or lower leg may feel numb, weak, or cold; tingle; or look
pale or blue. Acute injuries include:
strains, or other injuries to the ligaments and
tendons that connect and support the kneecap.
- A tear in the
rubbery cushions of the knee joint (meniscus).
tears, such as the anterior cruciate ligament (ACL). The
medial collateral ligament (MCL) is the most commonly
injured ligament of the knee.
- Breaks (fracture) of the
kneecap, lower portion of the femur, or upper part of the tibia or fibula. Knee
fractures are most commonly caused by abnormal force, such as a falling on the
knee, a severe twisting motion, severe force that bends the knee, or when the
knee forcefully hits an object.
dislocation. This type of dislocation occurs more
frequently in 13- to 18-year-old girls.
- Pieces of bone or tissue (loose bodies) from a fracture or dislocation that may get caught in the joint and
interfere with movement.
- Knee joint
dislocation. This is a rare injury that requires great
force. It is a serious injury and requires immediate medical care.
Overuse injuries occur with
repetitive activities or repeated or prolonged pressure on the knee. Activities
such as stair climbing, bicycle riding, jogging, or jumping stress joints and
other tissues and can lead to irritation and inflammation. Overuse injuries
- Inflammation of the small sacs of fluid that
cushion and lubricate the knee (bursitis).
- Inflammation of the tendons
(tendinitis) or small tears in the tendons
- Thickening or folding of the knee ligaments (plica
- Pain in the front of the knee from overuse, injury,
excess weight, or problems in the kneecap (patellofemoral pain syndrome).
- Irritation and inflammation of the band of
fibrous tissue that runs down the outside of the thigh (iliotibial band syndrome).
Conditions that may cause knee problems
directly related to an injury or overuse may occur in or around the
(degenerative joint disease) may cause knee pain that is worse in the morning
and improves during the day. It often develops at the site of a previous
injury. Other types of arthritis, such as
lupus, also can cause knee pain, swelling, and
Osgood-Schlatter disease causes pain,
swelling, and tenderness in the front of the knee below the kneecap. It is
especially common in boys ages 11 to 15.
popliteal (or Baker's) cyst causes swelling in the
back of the knee.
- Infection in the skin (cellulitis),
joint (infectious arthritis), bone (osteomyelitis),
bursa (septic bursitis) can cause pain and
decreased knee movement.
- A problem elsewhere in the body, such as a
pinched nerve or a problem in the hip, can sometimes cause knee
Osteochondritis dissecans causes pain and decreased
movement when a piece of bone or cartilage or both inside the knee joint loses
blood supply and dies.
Treatment for a knee problem or injury may
include first aid measures, rest, bracing, physical therapy, medicine, and, in
some cases, surgery. Treatment depends on the location, type, and severity of
the injury as well as your age, health condition, and activity level (such as
work, sports, or hobbies).
Check your symptoms to decide if and when
you should see a doctor.
Home treatment may help relieve
pain, swelling, and stiffness.
Rest and protect an
injured or sore area. Stop, change, or take a break from any activity that may
be causing your pain or soreness. When resting, place a small pillow under your
Ice will reduce pain and swelling.
ice or cold packs immediately to prevent or minimize swelling. Apply the ice
or cold pack for 10 to 20 minutes, 3 or more times a day.
- For the first 48 hours after an injury, avoid
things that might increase swelling, such as hot showers, hot tubs, hot packs,
or alcoholic beverages.
- After 48 to 72 hours, if swelling is gone,
heat and begin
gentle exercise with the aid of moist heat to help
restore and maintain flexibility. Some experts recommend alternating between
heat and cold treatments.
Compression, or wrapping the
injured or sore area with an elastic bandage (such as an Ace wrap), will help
- Don't wrap it too tightly, since this can
cause more swelling below the affected area. Loosen the bandage if it gets too
tight. Signs that the bandage is too tight include numbness, tingling,
increased pain, coolness, or swelling in the area below the
- Don't expect the bandage to protect or stabilize a knee
- Talk to your doctor if you think you need to use a wrap for
longer than 48 to 72 hours. A more serious problem may be present.
Elevate the injured or sore
area on pillows while applying ice and anytime you are sitting or lying down.
Try to keep the area at or above the level of your heart to help minimize
- Reduce stress on your sore knee (until you can get advice
from your doctor):
- Use a cane or crutch in the hand opposite
your painful knee.
- Use two crutches, keeping weight off the leg
with the sore knee. You can get canes or crutches from most pharmacies.
Crutches are recommended if a cane causes you to walk with a limp.
- Gently massage or rub the area to relieve pain and
encourage blood flow. Do not massage the injured area if it causes
- Try the following exercises to maintain flexibility:
- Hamstring stretch
- Knee-to-chest exercise
- Avoid high-impact exercise, such as running,
skiing, snowboarding, or playing tennis, until your knee is no longer painful
Do not smoke. Smoking slows healing because it decreases blood
supply and delays tissue repair. For more information, see the topic
Medicine you can buy without a prescription
| Try a nonprescription
medicine to help treat your fever or pain:
Acetaminophen, such as Tylenol
Nonsteroidal anti-inflammatory drugs (NSAIDs):
- Ibuprofen, such as Advil or Motrin
such as Aleve or Naprosyn
Aspirin (also a nonsteroidal
anti-inflammatory drug), such as Bayer or Bufferin
Talk to your child's doctor before switching back and
forth between doses of acetaminophen and ibuprofen. When you switch between two
medicines, there is a chance your child will get too much medicine.
| Be sure to follow these
safety tips when you use a nonprescription medicine:
- Carefully read and follow all directions
on the medicine bottle and box.
- Do not take more than the
- Do not take a medicine if you have had an
allergic reaction to it in the past.
you have been told to avoid a medicine, call your doctor before you take
- If you are or could be pregnant, do not take any medicine other
than acetaminophen unless your doctor has told you to.
Do not give aspirin to anyone younger than age 20 unless your doctor tells you to.
Symptoms to watch for during home treatment
Call your doctor if any of the following occur during home
Signs of infection
- Your knee becomes hard to move or swelling lasts for more than 2 days.
knee, lower leg, or foot becomes pale or cool or looks
- Symptoms do not improve with home
- Symptoms become more severe or frequent.
The following tips may prevent knee
General prevention tips
- Wear your seat belt in a motor
- Don't carry objects that are too heavy. Use a step stool.
Do not stand on chairs or other unsteady objects.
- Wear knee guards
during sports or recreational activities, such as roller-skating or soccer.
- Stretch before and after physical exercise, sports, or
recreational activities to warm up your muscles.
- Use the correct
techniques or positions during activities so that you do not strain your
- Use equipment appropriate to your size, strength, and
ability. Avoid repeated movements that can cause injury. In daily routines or
hobbies, look at activities in which you make repeated knee
- Consider taking lessons to learn the proper technique
for sports. Have a trainer or person who is familiar with sports equipment
check your equipment to see if it is well suited for your level of ability,
body size, and body strength.
- If you feel that certain activities
at your workplace are causing pain or soreness from overuse, call your human
resources department for information on other ways of doing your job or to talk
about using different equipment.
Tips specific to the knee
- Keep your knees and the muscles that support
them strong and flexible. Warm up before activities. Try the following
- Hamstring stretch
- Knee-to-chest exercise
- Calf stretch
- Straight-leg raises
- Avoid activities that stress your knees, such as
deep knee bends or downhill running.
- Wear shoes with good arch
- Do not wear high-heeled shoes.
- When playing
contact sports, wear the right shoes that are made for the surface you are
playing or running on, such as a track or tennis court.
running shoes every 300 to 500 miles (480 to 800 kilometers).
Experts recommend getting new athletic shoes every 3 months or after 500 miles
Tips specific to female athletes
recommend training programs that help women learn to run, jump, and pivot with
knees bent to avoid knee injuries. In sports such as soccer, basketball, and
volleyball, women who bend their knees and play low to the ground have fewer
knee injuries than women who run and pivot with stiff legs.
Knee brace use
Some people use knee braces to prevent
knee injuries or after a knee injury. There are many types of knee braces, from
soft fabric sleeves to rigid, metal hinged braces, that support and protect the
knee. If your doctor has recommended the use of a knee brace, follow his or her
instructions. If you are using a knee brace to help prevent problems, follow
the manufacturer's instructions for use.
Keep bones strong
- Eat healthy foods such as milk, cheese, yogurt, and dark green, leafy vegetables like broccoli. For more
information, see the topic
- Exercise and stay active. Talk to your doctor about exercises and activities that are right for you. Begin slowly, especially if you have been inactive. For more information, see
- Don't drink more than 2 alcoholic drinks a day if you are a man, or 1 alcoholic drink a day if you are a woman. Drinking alcohol increases your chances of having weak bones (osteoporosis). It also increases your chances of falling.
- Do not smoke or use other tobacco products. Smoking increases your chances of having osteoporosis. It also causes problems with the blood supply in your legs and slows healing. For more information, see the topic
Knee injuries such as bruises, burns, fractures, cuts, or punctures may be caused by abuse. Suspect possible abuse when an injury cannot be explained or does not match the explanation, repeated injuries occur, or the explanations for the cause of the injury change. You may be able to prevent further abuse by reporting it and seeking help.
To prepare for your appointment, see the topic Making the Most of Your Appointment.
You can help your
doctor diagnose and treat your condition by being prepared to answer the
- What are your main symptoms?
- How long
have you had your symptoms?
- What were you doing when your symptoms
- Have you had this problem in the past?
- What was the diagnosis?
- How was
- How and when did an injury occur? How was it
treated? Were illegal drugs or alcohol involved in your
- Have you had any injuries in the past to the same area? Do
you have any continuing problems because of the previous
- Have you ever had knee surgery?
activities, related to sports, work, or your lifestyle, make your symptoms
better or worse?
- Do you think that activities related to your job
or hobbies caused your symptoms?
- What home treatment measures have
you tried? Did they help?
- What nonprescription medicines have you
taken? Did they help?
- Do you have any
Animal and Human Bites
Burns and Electric Shock
Leg Problems, Noninjury