Significations et usages de Sprained_ankle

Sprained
Classification and external resources
Lateral view of the human ankle
ICD-10	S93.4
ICD-9	845.00
DiseasesDB	726
MedlinePlus	003167
eMedicine	topic list

A sprained ankle, also known as an ankle sprain, twisted ankle, rolled ankle, floppy ankle, ankle injury or ankle ligament injury, is a common medical condition where one or more of the ligaments of the ankle is torn or partially torn.

  Cause

Movements - especially twisting, turning, and rolling of the foot - are the primary cause of an ankle sprain.^[1]

The risk of a sprain is greatest during activities that involve explosive side-to-side motion, such as tennis or basketball. Sprained ankles can also occur during normal daily activities such as stepping off a curb or slipping on ice. Returning to activity before the ligaments have fully healed may cause them to heal in a stretched position, resulting in less stability at the ankle joint. This can lead to a condition known as Chronic Ankle Instability (CAI), and an increased risk of ankle sprains.

The following factors can contribute to an increased risk of ankle sprains:

• Weak muscles/tendons that cross the ankle joint, especially the muscles of the lower leg that cross the outside, or lateral aspect of the ankle joint (i.e. peroneal or fibular muscles);
• Weak or lax ligaments that join together the bones of the ankle joint – this can be hereditary or due to overstretching of ligaments as a result of repetitive ankle sprains;
• Poor ankle flexibility;^{[citation needed]}
• Lack of warm-up and/or stretching before activity;^{[citation needed]}
• Inadequate joint proprioception (i.e. sense of joint position);
• Slow neuron muscular response to an off-balance position;
• Running on uneven surfaces;
• Shoes with inadequate heel support; and
• Wearing high-heeled shoes – due to the weak position of the ankle joint with an elevated heel, and a small base of support.

  Types of sprains

  Inversion (lateral) ankle sprain

The most common type of ankle sprain occurs when the foot is inverted too much, affecting the lateral side of the foot. When this type of ankle sprain happens, the outer, or lateral, ligaments are stretched too much. The anterior talofibular ligament is one of the most commonly involved ligaments in this type of sprain. Approximately 90% of ankle sprains are inversion injuries.

  Eversion (medial) ankle sprain

A less common type of ankle sprain is called an eversion injury, affecting the medial side of the foot. When this occurs, the medial, or deltoid, ligament is stretched too much.

  High ankle sprain

A high ankle sprain is an injury to the large ligaments above the ankle that join together the two long bones of the lower leg, called the tibia and fibula. High ankle sprains commonly occur from a sudden and forceful outward twisting of the foot, which commonly occurs in contact and cutting sports such as football, rugby, ice hockey, roller derby, basketball, volleyball, lacrosse, softball, baseball, track, ultimate frisbee, soccer, tennis and badminton.

  Classification

Ankle sprains are classified as grade 1, 2, and 3.^[2] Some of the most common causes of ankle injuries are: lack of conditioning, lack of warming up and stretching properly, previous history of an ankle sprain, inadequate shoes, and uneven ground. Depending on the amount of damage or the number of ligaments that are damaged, each sprain is classified from mild to severe. A Grade 1 sprain is defined as mild damage to a ligament or ligaments without instability of the affected joint. A Grade 2 sprain is considered a partial tear to the ligament, in which it is stretched to the point that it becomes loose. A Grade 3 sprain is a complete tear of a ligament, causing instability in the affected joint.^[3] Usually bruising will occur around the ankle.

  Symptoms

Knowing the symptoms that can be experienced with a sprain is important in determining that the injury is not really a break in the bone. When a sprain occurs, blood vessels will leak fluid into the tissue that surrounds the joint. White blood cells responsible for inflammation migrate to the area, and blood flow increases as well.^[4] Along with this inflammation, swelling from the fluid and pain is experienced. The nerves in the area become more sensitive when the injury is suffered, so pain is felt as throbbing and will worsen if there is pressure placed on the area. Warmth and redness are also seen as blood flow is increased. Also present is a decreased ability to move the joint, and difficulty using the affected leg.

  Diagnosis

The diagnosis of a sprain relies on the medical history, including symptoms, as well as making a differential diagnosis, mainly in distinguishing it from strains or bone fractures. The Ottawa ankle rule is a simple, widely-used rule to help differentiate fractures of the ankle or mid-foot from other ankle injuries that do not require x-ray radiography. It has a specificity of nearly 100%, meaning that a patient who tests negative, according to the rule almost certainly does not have an ankle fracture.^[5]

  Treatment

Use of a proper compression wrap is the most important first step, that could include warming pads and icing.

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  Conservative measures

If the ankle is not swollen, it just hurts to walk on and has limited mobilization, it is generally recommended that the injured wear an orthopedic walking boot for two weeks and be on crutches for the first week at least. Ice is often used to reduce swelling in cycles of 20-30 minutes on and 20-30 minutes off. Icing an ankle too long may cause cold injuries, indicated if the area turns white.^[6]

In uncomplicated lateral ankle sprains, swelling of the soft tissue can be prevented with compression around both malleoli, elevation of the injured ankle higher than the heart, and pain-free exercises.^[7]

An orthopedic walking boot is often used for the treatment of a sprained ankle injury. Braces and crutches are also used to help alleviate the pain so the injured ankle can heal as quickly and painlessly as possible.

Although found to be less effective than casts, compression bandages are used to provide support and compression for sprained ankles. Wrapping is started at the ball of the foot and slowly continued up to the base of the calf muscle, pushing the swelling up toward the center of the body so that it does not gather in the foot. Bandages are kept tight, but not so tight as to cut off the circulation in the foot.^{[citation needed]}

  Rehabilitation

If an ankle sprain does not heal properly, the joint may become unstable and may lead to chronic pain.^[8] Receiving proper treatment and performing exercises that promote ankle function is important to strengthen the ankle and prevent further injury.

  Mobilization

A short period of immobilization in a below-knee cast or in an Aircast leads to a faster recovery at 3 months compared to a tubular compression bandage.^[9] Yet, a randomized controlled trial has concluded that appropriate exercise immediately after a sprain improves function and recovery.^[10] The exercises were focused on increasing ankle range of movement, activation and strengthening of ankle musculature, and restoring normal sensorimotor control, and were carried out for 20 minutes, three times a day.^[10]

The amount of therapy that a person can handle will depend on their level of pain and the grade of sprain they experienced. It is not recommended to return to sports or extreme physical activities until hopping on the ankle is achieved without pain. Wearing high-top tennis shoes may also help prevent ankle sprains if the shoes used are laced snugly and if the ankle is taped with a wide, nonelastic adhesive tape.^[11]

  Ankle exercises

To prevent sprains or re-injury from occurring, strengthening and stretching exercises should be done through a full range of ankle motion. To improve ankle mobility, ankle circles can be performed by extending the legs in front of the body and then moving the foot up and down, side to side, or rotating the foot in a circle. Another common exercise to improve mobility as well as proprioception is to use the toes to draw the letters of the alphabet in the air. Most importantly, the lateral aspect of the ankle joint should be strengthened with eversion exercises (i.e. underside of the foot is turned outward against resistance) to improve lateral ankle stability.^[12] Stretching is also an important component of a strengthening program, to help maintain joint flexibility.

Balance and stability training are especially important to retrain the ankle muscles to work together to support the joint.^[13] This includes exercises that are performed by standing on one foot and using the injured ankle to lift the body onto its toes. To further enhance balance and stability, exercise devices such as the wobble board can be used, progressing from double-leg to single-leg stance, first with eyes open and then with eyes closed, for enhanced effectiveness.

Other strategies that can be used to prevent ankle injury include:

• Ensure proper warm-up prior to stretching and activity;
• When running, choose level surfaces and avoid rocks or holes;
• Ensure that shoes have adequate heel support; and...
• If high-heeled shoes are worn, ensure that heels are no more than 2 inches in height, and avoid heels with a narrow base.

  Prognosis

Most people improve significantly in the first two weeks. Some however still have problems with pain and instability after one year (5–30%). Reinjury is also common.^[14][15]

  Image gallery

• 

  Right foot, housed in an air brace, has become swollen as a result of a more severe 2nd degree sprain to the ankle.

• 

  Right foot. A light sprain, two days after injury. Patient had trouble walking normally for 2 months.

• 

  Right foot. One day after injury.

  References

• "Ankle sprains - A new concept in treatment"]- HardlyWorkingatHome.com

  External links

• Overview at uchc.edu