What causes a sprain or strain?
Sprains and strains occur when the body is put under physical stress. In these situations, muscles and joints are forced to perform movements for which they are not prepared or designed. An injury can occur from a single stressful incident, contact sports, or it may gradually arise after many repetitions of a motion. Usually, the mechanism of injury involves placing the muscle tendon unit or the ligament under excessive stretching, causing damage to the muscle, tendon, or ligament fibers.
Where do sprains and strains usually occur?
An ankle sprain is one of the most common injuries of a joint. Usually, the mechanism of injury is a rapid “rolling” or “twisting” of the ankle and turning it inward (inversion) so that the sole of the foot starts to point upward (supination). This causes stretching and damage to the ligaments on the outside or lateral part of the ankle that hold the joint stable. While common and many are mild sprains, some ankle sprains can be severe.
Knee sprains are common sports injuries and often make headlines because of their potential for ending professional athletes’ playing careers. There are four ligaments of the knee that allow it to act as a hinge joint, flexing (bending) or extending (straightening). The medial and lateral collateral ligaments and the anterior and posterior cruciate ligaments keep the knee in alignment and are assisted by the quadriceps and hamstring muscles. When a player completely tears the anterior cruciate ligament (ACL) in the knee, it is described as a grade 3 injury of that cruciate ligament.
Neck injuries are common, for example, after a car accident. While whiplash is a nonmedical term, it accurately describes the head and neck movement when violently flexed forward and backward as the car abruptly stops. While the rest of the body is held in place with a seat belt and/or air bag, the head is like a bobble head and can continue moving. Both muscles and ligaments hold the neck bones (cervical vertebrae) in place, and the stresses placed on those structures can cause severe pain and damage. Sometimes, the vertebrae are not damaged, but the ligaments that support and stabilize the bones are torn, causing significant pain and swelling. On occasion, these injuries can cause the neck to become unstable and put the spinal cord at risk for injury.
Wrist injuries are common because we use our hands to perform many tasks. Usually, the wrist is damaged because of a fall, but repetitive tasks and a single aggressive move may also cause pain. Some sports are more prone to wrist injuries than others because of the forces that are placed on the joint. Sports injuries from throwing motions can occur in baseball, football, bowling, and tennis. Sports injuries from falling on an outstretched hand may happen with skateboarding, snowboarding, and skiing.
The thumb and fingers can also be injured. Skier’s or gamekeeper’s thumb is a sprain at the base of the thumb where the ulnar collateral ligament spans the metacarpophalageal joint, where the thumb attaches to the hand. This ligament holds the thumb stable during grasping and pinching motions. It is most often injured in a fall where the thumb is forced away from the palm of the hand, like when a skier falls and the ski pole pushes the thumb in an awkward direction.
Muscles strains may involve any body area that is required to perform work. Lower back pain and spasm is a common result of repetitive lifting injuries, but it only takes one twist or turn at the wrong time or in the wrong position to cause muscle fibers in the back to stretch and develop spasms. Low back strain is the most common work-related injury.
Muscles need to be well-balanced around the joints they move. For example, muscles can be damaged from overuse or imbalance. The quadriceps muscle in the front of the thigh extends the knee and is balanced by the hamstring muscles of the back of the thigh, which flex the knee. Excess bending or straightening can cause the muscle fibers to tear. Muscles that move and stabilize the hip are prone to injury. Groin injuries or groin pulls are strains of the hip muscles that normally move the thigh inward to the middle of the body. When the leg is pulled away from the body like doing the splits, the adductors are stretched and potentially damaged.
We use our arms and hands for a variety of activities, and the arm muscles (biceps and triceps muscles) and the forearm muscles may be strained by aggressive lifting, pushing, pulling grabbing, twisting, or any other activity that you can imagine the arm and hand trying to accomplish.
Chest wall muscles can be pulled or strained because of activities as aggressive as lifting or as seemingly harmless as sneezing or coughing. Acute strains of the large muscles on the outside of the chest (pectoralis muscles) or the muscles between the ribs (intercostal muscles) can cause severe pain and can mimic the pain of a broken rib.
The core muscles of the torso of the body, including the abdominal wall muscles and those of the back, lend stability to the trunk and are often the source of power for the arms and legs to lift and push. These muscles can be strained from many different activities that require the torso to bend, stretch, or twist.