Knee sprains may be caused by:
- forced twisting of the knee
- stopping suddenly while running
- shifting your weight while running or skiing
- landing awkwardly after jumping
- a blow to the outer or inner side of the knee
- a blow to the front of the knee while the knee is bent and the foot is firmly planted on the ground
Risk factors that increase your chances of spraining your knee include:
- playing sports
- poor coordination
- poor balance
- inadequate flexibility and strength in muscles and ligaments
- loose joints
Symptoms of a knee sprain include:
- pain in the knee
- swelling, redness, warmth or bruising around the knee
- decreased range of motion in the knee
- inability to stand on the affected leg
- tenderness where the injured ligament attaches to a bone in the knee
- swelling within the knee
The doctor will ask about your symptoms and how you injured your knee. The doctor will examine your knee to assess the stability of the joint and the severity of the injury.
Tests may include:
- X-rays — to make sure that no bones are broken
- MRI scan — to see if a ligament has torn completely (less common)
Knee sprains are graded according to their severity. In addition, the more ligaments involved, the more severe the injury.
- stretching and microtearing of ligament tissue
- partial tearing of ligament tissue
- mild instability of the joint when tested
- severe or complete tearing of ligament tissue
- significant instability of the joint
Avoid putting any pressure on your knee by not walking on that leg.
Apply ice or a cold pack to the knee for 15-20 minutes, 4 times a day for 2 days. This helps reduce pain and swelling. Wrap the ice or cold pack in a towel. Do not apply the ice directly to your skin.
Wrap your knee in an elastic compression bandage (e.g., Ace bandage). This will limit swelling and provide some support for your knee.
Keep the injured knee raised above the level of your heart for 24 hours. This will help drain fluid and reduce swelling.
Take one of the following drugs to help reduce inflammation and pain:
- ibuprofen (Motrin, Advil)
- naproxen (Aleve, Naprosyn)
- acetaminophen (Tylenol)
You may need to wear a brace to immobilize your knee. If you play sports, you may need to wear a knee brace when you return to play.
- leg cast
If you have a severe sprain, your doctor may recommend a short leg cast for 2-3 weeks.
- rehabilitation exercises
Begin exercises to restore flexibility, range of motion, and strength in your knee as recommended by your health care professional.
Surgery is often needed to repair a ligament that is torn completely. Some external ligaments can heal without surgery, but internal ligaments will not.
Many knee sprains cannot be prevented. To reduce your risk of spraining a knee:
- Take a break from sports or exercise when you feel tired.
- Do exercises that strengthen the leg muscles.
- Learn the proper technique for exercise and sporting activities. This will decrease stress on all your muscles, ligaments and tendons, including those around your knee.
How can I prevent a knee sprain?
Athletes can take three steps to reduce their risk of a knee sprain:
- Training and conditioning should be a year-round program. Skill drills and strength and flexibility exercises will enhance balance and coordination so you will be ready when the season starts.
- Make strengthening exercises for the hamstrings and quadriceps muscles a regular part of your conditioning program.
To stretch the quads, stand and use a wall or table for support. Lift one leg and pull your foot towards your buttocks. Hold for five seconds, then release the foot and stand straight. Repeat six to ten times on one side, then turn and repeat on the other side.
To stretch the hamstrings, sit with one knee bent and the other leg extended, toes pointing to the ceiling. Lean forward until you feel a stretch. Hold for five seconds then return to your original position.
Repeat six to ten times on each leg.
- Practice proper landing technique (from a jump) and learn to do cutting maneuvers in a crouched posture with a slight bend at the knee and the hip.
- Take a break from activity when you feel tired
Improving sports performance
The key to improving sports performance after a knee sprain is a proper rehabilitation program, and adhering to some of those same principles after the injury is gone.
Keep in mind that the single most important aspect of improving performance is stretching before and after you step onto the field, court, ice, or golf course.
Benefits derived from stretching include:
- increased physical efficiency and performance
- decreased risk of injury
- increased blood supply and nutrients to joint structures
- increased coordination
- improved muscular balance and postural awareness
- decreased risk of lower-back pain
- reduced stress
- enhanced enjoyment
Knee sprain rehabilitation for athletes
Often caused by a sudden twisting motion, knee sprains are one of the most common football injuries. For a mild sprain (Grade 1), your doctor may recommend an exercise program to strengthen muscles surrounding the knee. The doctor may also prescribe a protective knee brace for you to wear during activity, and in some cases, may prescribe you to wear a leg cast for two to three weeks.
For torn ligaments (Grade 2 or Grade 3 knee sprain), such as a torn ACL, torn PCL, or meniscal tears, your doctor is likely to recommend surgery, in which the torn ends of the ligament are reattached or reconstructed.
As an athlete, you may already know that one of the most common and best ways to begin rehabilitating a sprain is R.I.C.E.:
Avoid putting any pressure on your ankle by not walking on it.
Apply ice or a cold pack to the ankle for 15-20 minutes, 4 times a day for at least 2 to 3 days. This helps reduce pain and swelling. Wrap the ice or cold pack in a towel. Do not apply the ice directly to your skin.
Wrap your ankle in an elastic compression bandage (e.g., Ace bandage). This will limit swelling of your ankle.
Keep your ankle raised above the level of your heart as often as possible for the first 48 hours. This will help drain fluid and reduce swelling.
You can begin exercise rehabilitation when the swelling subsides, which is usually a few days after the injury. Because warmed tissue is more flexible and less prone to injury, you may want to warm the knee before doing rehabilitation exercises. Use ice when finished to minimize any irritation to the tissue caused by the exercise.
To get you back in the game as quickly as possible, there are three main goals in rehabilitating the knee: restoring motion and flexibility, restoring strength, and restoring balance.
- Front thigh muscle sets
Sit with legs extended and fully contract the muscles of the front thighs. Hold contractions for 10 seconds. Repeat 10 times.
- Straight-leg raises
Lie with one leg extended and the other bent at the knee. Lift the entire leg from the hip so that the heel is about 5 inches above the floor or ground. Hold this position for 5 to 10 seconds, then slowly lower the leg. Repeat 10 times for each leg.
- Backward leg raises
Lie on stomach with legs straight. Lift one leg as high as possible and hold for 5 to 10 seconds. Repeat 10 to 20 times for each leg.
- Half-knee bends
Stand with feet shoulder width apart or as the injury improves, try to stand with feet together. Slowly lower the body weight by bending the knees. Do not perform a full squat but rather stop at about half of the full-squat position and then fully extend the knees. If there is pain before achieving the half-squat position, stop downward travel at that point. Repeat 10 to 20 times.
Once knee pain has been minimized, you may swim, cycle, walk, stair climb, weight train, or jog, as pain allows. These activities will help you to gradually return to full training. Also remember to continue these stretching, strengthening, and range-of-motion exercises in order to reduce the risk of injury recurrence.
During the period when normal training should be avoided, alternative exercises may be used. These activities should not require any actions that create or intensify pain at the site of injury. They include:
- water running
- stationary bicycle (add resistance gradually from one session to the next, as pain allows).
Rehabilitation after surgery
An athlete who wishes to return to sports that involve jumping, cutting, and pivoting may need surgery to reconstruct the ligament if it’s torn completely. This stabilizes the knee, preserves the cartilage, and enables a return to sports at the same level as prior to the surgery. After surgery, exercise and rehabilitative therapy are required to strengthen the muscles and restore mobility. With this procedure, most athletes can return to their chosen sport at the same level
Keep in mind that if your knee injury requires surgery, the soft tissue needs time to heal before exercise can begin. While in the hospital, patients start partial weight bearing with exercises to re-establish knee joint mobility and normal gait. In these cases, you would be required to wear a brace and use crutches for the first six weeks.
A physical therapy program usually begins with range-of-motion and resistive exercises, then incorporates power, aerobic and muscular endurance, flexibility, and coordination drills.
Finally, patients develop speed and agility through sport-specific exercise routines. A typical patient may begin to ride a bike at three months, start running at five to seven months, and return to competitive sports after eight to 12 months. Full recovery may take up to two years.
The ultimate goal of reconstructive knee surgery is to provide dynamic stability while maintaining full range of motion, so that athletes can return to competitive or recreational sports. Progress is assessed by the patient’s perception of how stable the knee feels and by comparing the strength and stability of the injured and uninjured knees.
When can I return to my sport or activity?
The goal of rehabilitation is to return you to your sport or activity as soon as is safely possible. If you return too soon you may worsen your injury, which could lead to permanent damage. Everyone recovers from injury at a different rate. Return to your activity is determined by how soon your knee sprain recovers, not by how many days or weeks it has been since your injury occurred. It also depends on how serious the injury is. Instances where reconstructive surgery is required will obviously create a longer recovery period than patients with a mild sprain.
A good rule is to allow pain to dictate when you’re ready to return to activity. You should return in moderation, and back off if you feel any pain.
The ultimate goal of reconstructive surgery is to provide dynamic stability while maintaining full range of motion, so that athletes can return to competitive or recreational sports. Progress is assessed by the patient’s perception of how stable the knee feels and by comparing the strength and stability of the injured and uninjured knees.
You may safely return to your sport or activity when, starting from the top of the list and progressing to the end, each of the following is true:
- You have full range of motion in the injured knee compared to the uninjured knee.
- You have full strength of the injured knee compared to the uninjured knee.
- You can jog straight ahead without pain or limping.
- You can sprint straight ahead without pain or limping.
- You can do 45-degree cuts, first at half-speed, then at full-speed.
- You can do 20-yard figures-of-eight, first at half-speed, then at full-speed.
- You can do 90-degree cuts, first at half-speed, then at full-speed.
- You can do 10-yard figures-of-eight, first at half-speed, then at full-speed.
- You can jump on both legs without pain and you can jump on the injured leg without pain.
How long will the effects of the injury last?
With proper rehabilitation, a first occurrence of pain that is diagnosed and treated in its early stages with rest, ice, elevation, and compression usually lasts two weeks. If the injury has recurred several times, full recovery may take as long as six weeks.
Frequent episodes of knee sprains may result in a ligament tear. Such a complication may require surgical treatment, and full recovery under such circumstances can take up to two years, depending on the severity.