Ankle sprains and strains are two common injuries that can cause a significant amount of pain.
The ankle joint involves a series of interconnected ligaments, muscles, and tendons, all of which can be subject to acute or chronic sprain or strain.
This complex ankle design makes it a relatively stable joint compared to other joints in the body, and this stability is essential to its function. The ankle sustains 1.5 times the body's weight in impact with every walking step, and up to 8 times the body's weight with each step when running or jumping.
In high-impact activities, the normally stable ankle is subject to increased injury risk, especially when it turns or twists too far out of its normal range of motion.
Ankle injuries commonly occur due to:
- Acute injury that forces the ankle joint beyond its normal range of motion, such as in a sports injury or falling off a curb.
- Overuse injury caused by repetitive forces, such as repeated hard landings involved in sports such as long distance running and basketball.
Description of ankle sprains and strains
While many of the symptoms and treatments are similar for sprains and strains, they actually involve two different body tissues, and typically have different causes.
An ankle sprain is a common acute injury, with over 25,000 people in the United States experiencing it each day.1 It can affect adults and children, athletes and non-athletes, and can occur as a result of playing vigorous sports or simply taking a bad step off a curb.
Ankle sprains are caused by direct or indirect trauma to the ankle ligaments.2
In a sprain, the ankle ligaments that normally support the ankle are either stretched beyond their normal limits or torn outright as a result of this trauma. The sprain can occur when the ankle is forced beyond its normal range of motion, such as when people twist their ankle when making a sudden stop on an athletic field or track, walking or running on an uneven surface, or when tripping over an obstacle.
If not treated, or with repeated sprains of the same tissues, pain and dysfunction from acute ankle sprains can become chronic.1
An ankle strain is an injury that occurs when ankle muscles and/or their connecting tendons are either stretched beyond their normal limits or torn outright. Strains may be acute or chronic. The muscular injury often occurs at the point where the muscle connects to a tendon,3 and may be a side effect of or coexist with ankle tendonitis, which is the acute inflammation of one or more tendons in the ankle.
Less common than ankle sprains, ankle strains often occur due to chronic overuse of the ankle. This type of injury can occur due to activities such as running long distances, repeated hard landings from jumping (such as in basketball layups or volleyball sets), or repeated hard articulations of the ankle, such as going up on tiptoe in ballet or gymnastics.
Ankle strains can also occur due to an acute injury, such as a direct blow onto the lower body, or being tripped or tackled on the legs during contact sports. Strains can also occur due to overstretching of the ankle, or by excessive contracting of the muscles, which can occur when lifting heavy leg weights or kicking a ball forcefully.2
Understanding these two distinct conditions can help injured people seek the right treatment and avoid possible re-injury.