Sprains and Strains

• Facts
  • Sprains and strains facts
• What Is the Difference?
  • What is the difference between a sprain and a strain?
  • Where can people find more information about sprains and strains?
• Causes
  • What causes a sprain or strain?
  • Where do sprains and strains usually occur?
• Signs/Symptoms
  • What are sprain symptoms and signs?
• Diagnosis
  • How do health care professionals diagnose sprains and strains?
• Treatment
  • What is the treatment for sprains and strains?
• Recovery Time
  • What is the recovery time for sprains and strains?
• How to Prevent
  • Is it possible to prevent sprains and strains?
• Prognosis
  • What is the prognosis of sprains and strains?

• A sprain is abnormal stretching or tearing of a ligament that supports a joint.
• A strain is abnormal stretching or tearing of a muscle or tendon.
• Sprains and strains may be caused by repetitive activities or by a single overuse injury.
• Pain, swelling, and bruising are common signs and symptoms of sprains and strains.
• The diagnosis of a sprain or strain usually can be made after the health care professional takes a history of the injury and performs a physical examination. Depending upon the situation, X-rays, a CT scan, or an MRI may be needed to help make or confirm the diagnosis.
• Physicians grade sprain and strains based on how much damage has occurred to the muscle, tendon, or ligament. A grade three injury, where the muscle or ligament is completely torn, is considered the most severe strain or severe sprain.
• RICE (rest, ice, compression, and elevation) are the first aid keys to initial treatment.
• Most sprains and strains resolve with time, but occasionally other treatments, including physical therapy and surgery, may be required.
• Anti-inflammatory medications may be helpful in decreasing the pain and inflammation of the injury.

The soft tissues of the body include the muscles, tendons, and ligaments that help the body move but are not part of the bony skeleton. Sprains and strains are considered soft tissue injuries.

• A sprain is an injury to a ligament.
• A strain is an injury to muscle or tendon tissue.

How muscles work

The purpose of the musculoskeletal system is to allow the body to move. A muscle attaches to bone on each side of a joint, either directly or by way of a tendon. When the muscle contracts, the joint moves through its range of motion. The muscle that you can feel moving underneath your skin is really made up of many smaller bundles of muscle fibers called fascicles. These, in turn, are made up of individual muscle fibers that are crosslinked to allow them to slide back and forth within the fascicle. Sliding together causes the muscle fibers to shorten and the muscle to contract and move the joint. When the muscle relaxes, the muscle fibers return to their resting position and as the fibers elongate, the joint may return to its previous position.

The transition of muscle to tendon happens gradually as muscle fibers give way to tendon fibers before the bony attachment occurs. The anatomy of each tendon is different and depending upon their location in the body, the tendon portion may be very short or very long. A strain is damage caused by an overstretched muscle or tendon, causing their fibers to be pulled apart, losing the ability to adequately contract. The severity of injury depends upon the amount of tissue that is damaged. The muscle fiber may be just stretched, partially torn, or completely torn apart.

The most common cause of a muscle or tendon strain is overuse, which weakens the tissue fibers. Muscles and joints may also be forced to perform movements for which they are not prepared or designed, stretching and potentially damaging the surrounding muscle or tendon. An injury can occur from a single stressful incident, or it may gradually arise after many repetitions of a motion (overuse). The damage can occur in three areas: the muscle itself, the muscle tendon intersection where the muscle fibers transition to tendon fibers, or the tendon itself.

Strains are described by the severity of damage in three grades:

• Grade 1 strain usually causes stretching of a few of the muscle fibers.
• Grade 2 strain has more significant damage, and some muscle fibers are damaged or torn.
• Grade 3 strain is a complete rupture of the muscle.

How joints work

Joints are stabilized by thick bands of tissue called ligaments that allow the joint to move only in specific directions. Some joints move in multiple planes. Therefore, they need more than one group of ligaments to hold the joint in proper alignment. The ligaments are anchored to bone on each side of the joint. If a ligament is stretched or torn, the injury is called a sprain.

The grading system for sprain injury is similar to that of strains.

• Grade 1 sprains occur when fibers of the ligament are stretched but not torn.
• Grade 2 sprains are injuries where the ligament is partially torn.
• Grade 3 sprains occur when the ligament is completely torn or ruptured.

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.

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.

The first symptom of a sprain or strain injury is usually pain, though there may be a delay in onset of the symptom until there is some onset of muscle spasm. The person who is injured may not recall the specific event that caused the injury of the affected area. For example, a person who paints a room may develop shoulder pain the day after the repetitive effort of brushing overhead. This is because inflammation, swelling, and spasm can take time (from minutes to hours) to develop.

Pain is always a symptom that indicates that there is something wrong with the body. It is the message to the brain that warns that a muscle or joint should be protected from further harm. In work, exercise, or sport, the pain may develop after a specific incident, or it may gradually progress after many repetitions of a motion.

Swelling almost always occurs with injury, but it may take from minutes to hours to be noticed. Anytime fibers of a ligament, muscle, or tendon are damaged, some inflammation and bleeding occurs. The bleeding (such as bruising on the surface of the skin) may take time to be noticed.

Because of pain and swelling, the body starts to favor the injured part. This may cause the muscles that surround the injured area to go into spasm or cramp. Hard knots of muscle might be felt near the site of the injury.

The combination of pain, swelling, and spasm causes the body to further protect the injured part, which results in difficulty with use. Limping is an example of the body trying to protect an injured leg from weight-bearing.

The diagnosis of a muscle strain or joint sprain is usually made by history and physical examination. The health care professional may want to know the circumstances of the injury and whether the body sustained damage other than the sprain or strain that initially causes the patient to seek care. For example, if a person was involved in a significant fall or car accident, the strain or sprain may not be a priority in caring for the patient with potential internal bleeding or head injury.

Physical examination may focus on the part of the body that is injured: the tender muscle or the swollen joint. It is important to know whether or not there may be broken bones (fractures) or other associated injuries with the sprain or strain. The health care professional may evaluate the pulses and sensation beyond the injury site to be certain that there is no associated artery or nerve damage.

X-ray tests may be used to detect broken bones. CT scan or MRI are used to evaluate bone and can also help detect damage to muscles, tendons, ligaments, cartilage, and other structures. Usually, physical examination is adequate to make the diagnosis, but if surgery is suggested, imaging might be considered to help plan the operation. Most often CT and MRI tests are performed electively and scheduled to be done at a future time.

Sometimes X-rays are not recommended. For example, patients with low back pain who have not had a significant fall, car accident, or injuries (and there is little concern that a broken bone exists) do not particularly require X-rays since fracture is unlikely. The health care professional may wish to minimize the exposure to radiation by avoiding these. For ankle and knee sprains, guidelines (like the Ottawa ankle and knee rules) exist to help decide when X-rays of those joints might be helpful in finding an accompanying fracture. Usually, though, physical examination is enough to clinically assess the presence or absence of a bony injury.

When muscle, tendon, or ligament fibers are damaged, the body will heal that area by producing scar tissue. The area that is injured needs to be kept relatively rested while healing.

First aid continues afterward with rest, ice, compression, and elevation (RICE). These are the keys elements in the treatment of both sprains and strains. More intense treatment may be required depending upon the location and severity of injury and the patient's level of function. For example, an athlete who sprains the ACL of their knee may need to have surgery to reconstruct the ligament, but an elderly patient who is less active may not need such an aggressive approach and physical therapy may be all that is needed to return to their previous level of activity.

Depending upon the extent and location of the injury, it may take many weeks to return to normal function. That does not mean that all activity must stop; instead there needs to be a gradual return to function that is guided by the body's response to activity. Most often, the patient can "listen" to their body's response to activity and increase or decrease the amount and intensity of activity. There is a balance between resting a part of the body enough to help with healing and resting it too much so that strength and range of motion are lost. For example, when the rotator cuff is strained, it may take a significant amount of time for the shoulder to return to full function. Resting the arm for a prolonged period of time in a sling to rest the muscle group may lead to stiffness in the shoulder joint and loss of range of motion. The health care professional and patient must appreciate that balance and minimize the loss of function while maximizing the rate of healing.

Muscle, tendon, and ligaments heal themselves naturally by repairing the fibers or filling in the damaged area with scar tissue. Full muscle and joint mobility may take time to return, and gradual stretching may be required to return the injured area to normal. Additionally, depending upon the area of the body that is injured, the damage sustained, and the amount of loss of function, physical therapy may be suggested. A variety of treatment modalities may be considered, including ultrasound and massage, to encourage healing and preserve range of motion and function.

If the muscle or tendon is ruptured or severely torn (grade 3 strain), surgery may be required to repair the damage. Some common sites of this injury include the

• quadriceps (front of the thigh) muscle or its tendon, either the quadriceps or patellar, that allows the knee to extend or straighten tendon;
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