While the terms sprain and strain are commonly used interchangeably, they actually mean two different things. A sprain is an injury to a ligament whereas a strain is an injury to a tendon.
A ligament is a fibrous, tough structure that connects one bone to another bone. A ligament sprain occurs when that structure is overstretched or partially torn. These are commonly seen in the knee, the ankle and the wrist. Falling on an outstretched wrist for example may result in a ligament sprain. In addition, twisting your knee or rolling your ankle may have the same result. Ligament strains can vary in severity and are graded on a scale from 1-3.
Tendons are flexible but inelastic cords of strong fibrous collagen tissue which connects muscle to bone. Strains can also very in degree and can range from a minor over stretching to a partial or complete tear. Common strains are Achilles tendon, patella tendon, hamstring, lower back and cervical strains commonly referred to as whiplash. Strains are graded on a scale of 1-4.
Signs and Symptoms
Sprains typically occurs when people fall and land on an outstretched arm, misstep and land on the side of their foot, or twist their knee while the foot planted firmly on the ground. This results in an overstretch or tear of the ligaments supporting that joint. Sprains are an acute injury and the patient almost always can recount the injury which caused the sprain.
Strains are caused by twisting or pulling a muscle or tendon more than it is capable of or in a direction that it does not naturally stretch. Sometimes, when the strain is acute, people feel a pop or tear when the injury happens. A chronic strain is generally the result of overuse which is prolonged or repetitive use of the muscles and tendons.
The typical signs and symptoms of a tendon and ligament injuries are similar and include pain, swelling, bruising, and possible loss of functional ability. These signs and symptoms can vary in presentation and intensity, depending on the severity of the injury.
When to seek medical attention
Most low-grade sprains and strains will resolve on their own with rest, ice and time. If you are unsure how serious your injury is or if you are in significant pain. In addition, you should seek medical care if you are: