A lateral ligament injury usually refers to a tear of one or more of the ligaments on the outside of the ankle. The 
lateral ligaments consist of three ligament bands which provide stability to the outside of the ankle joint, preventing rolling in of the foot. The anterior talofibular ligament, stretching from the outside ankle bone to the front, is one of the most commonly involved ligaments torn. Sprains to the outside aspect of the ankle account for 85% of ankle sprains.
CAUSE
The lateral ligaments are injured when they are overstretched (sprained). This occurs when the foot and ankle are forcibly rolled inwards. The ankle may be sprained during rapid changes in direction, on uneven surfaces, or treading on a ball or opponent’s foot. Most sprains occur during shifting after the foot has been planted. Ligaments then stretch or tear depending on the amount of force that was placed on it. This can occur during the fast motions of sports or simply while walking on an uneven surface. 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. The amount of force that is placed on the ankle helps classify which grade of sprain is suffered. A mild sprain or one that causes slight stretching with minimal damage to the fibers in the ligament is considered a Grade 1 sprain. When there is some tearing of the ligament and the ankle joint moves in abnormal ways, it is noted to be a Grade 2 sprain. The final classification is Grade 3 sprain and includes severe injuries. These are ones where complete tears of a ligament and the presence of instability is experienced. Usually bruising will occur around the ankle but this can be prevented by applying ice.
SYMPTOMS
The first sensation felt is pain on the outside and front of the ankle. There may also be an audible snap, crack or tear. Depending on the severity of the injury, the outside and front of the ankle may swell and you may have difficulty walking due to pain. Swelling can be immediate or happen over a few hours. You may also develop bruising up the leg or down to the toes. Your ankle may also feel weak.
TREATMENT
For acutely injured ankles Rest, Ice, Compression and Elevation (RICE) is
recommended. Ice can help reduce swelling when applied in cycles of 10–15 minutes on and 60–90 minutes off. Be careful of suffering an ice burn – don’t leave the ice on too long and cover the ice in a damp cloth. Physiotherapy is recommended to control excessive inflammation and swelling initially as well as using braces and crutches. Compression bandages 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 Rehabilitation of muscle strength/stability as well as proprioception (sense of awareness of position and balance) and biomechanical analysis is imperative to prevent re-injury and return to sport.