Sprains and Strains

What are sprains and strains?

Is it a Sprain or Strain?
Pain, swelling, and bruising are common signs and symptoms of sprains and strains.

A sprain is abnormal stretching or tearing of a ligament that supports a joint. A strain, on the other hand, is abnormal stretching or tearing of a muscle or tendon. Both may be caused by repetitive activities or by a single overuse injury.

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.

Most sprains and strains resolve with time, but occasionally other treatments, including physical therapy and surgery, may be required. Anti-inflammatory medications may help decrease the pain and inflammation of the injury.

What is the difference between a sprain and a strain?

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 a 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 made up of many smaller bundles of muscle fibers called fascicles. These, in turn, are made up of individual muscle fibers that are cross-linked 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 its fibers to be pulled apart, losing the ability to adequately contract. The severity of the 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.

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 or 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 to 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. Four ligaments of the knee 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 airbag, the head is like a bobblehead 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 metacarpophalangeal 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.

Muscle strains may involve any body area that is required to perform work. Lower back pain and spasms are 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.

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What are symptoms of sprains?

The first symptom of a sprain or strain injury is usually pain, though there may be a delay in the 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 to 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 spasms 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 occur. 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 spasms or cramps. 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.

How do healthcare professionals diagnose sprains and strains?

The diagnosis of a muscle strain or joint sprain is usually made by history and physical examination. The healthcare professional may want to know the circumstances of the injury and whether the body sustained damage other than the sprain or strain that initially caused 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 sensations 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 scans or MRIs 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 help find an accompanying fracture. Usually, though, physical examination is enough to clinically assess the presence or absence of a bony injury.

What is the treatment for sprains and strains?

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 key elements in the treatment of both sprains and strains. More intense treatment may be required depending on the location and severity of the 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 the 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 in a sling to rest the muscle group may lead to stiffness in the shoulder joint and loss of range of motion. The healthcare professional and patient must appreciate that balance and minimize the loss of function while maximizing the rate of healing.

Muscles, tendons, 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 a 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 following:

  • The quadriceps (front of the thigh) muscle or its tendon, either the quadriceps or patellar, allows the knee to extend or straighten the tendon
  • The hamstring muscle located in the back of the thigh and flexes the knee
  • Achilles tendon which attaches the calf muscle to the calcaneus (heel) and allows the ankle to flex
  • The biceps muscle or tendon, which flexes the elbow

Physical therapists may be an important part of the treatment team to help with recovery. Their skills in teaching and monitoring range of motion and strengthening exercises allow recovery from their injury in a controlled way. It may be only one visit for an ankle sprain, or there may need to be multiple visits to help with post-operative care. Physical therapy can also involve other treatment options like ultrasound, electrical stimulation, and muscle massage.

Certified athletic trainers work with athletes, especially in organized sports, and are involved in the treatment of acute and chronic sprains and strains. They are skilled in taping and using compression bandages (ace wraps) to support and protect injured muscles and joints, as well as implementing treatment plans as part of the sports medicine team.

Surgery is a consideration for certain sprains and strains. The decision to offer surgical operations to repair muscles, tendons, or ligaments depends upon the patient's underlying function before the injury and their expectations for activity after recovery. Not all structures need repair, even if completely torn. For example, a professional athlete may continue to perform at a high level even with a torn posterior cruciate ligament in the knee but cannot easily return to the field of play with a torn anterior cruciate ligament.

Anti-inflammatory medications like ibuprofen (Advil, Motrin) and naproxen (Aleve) are often suggested to help decrease inflammation and relieve pain. Before taking any over-the-counter medication, it is important to appreciate that side effects and medication interactions exist and it is wise to ask a health care professional or pharmacist for advice and direction for their use.

New treatments are being developed to help with recovery For example, platelet-rich plasma (PRP) injections may help in speeding recovery and may be useful in some patient treatment plans.

For more significant pain, prescription pain medications, muscle relaxants, and/or anti-inflammatory medications may be prescribed for a short period.

What is the recovery time for sprains and strains?

The goal of treatment after a sprain or strain is to return the patient to their previous level of function before the injury. The duration of recovery depends upon the extent of the injury and what part of the body is damaged. The most important therapy for all injuries is allowing time to recover and heal.

Rehabilitating an injury may involve a home exercise program or it may be a formal physical therapy program. Regardless, it takes time and effort to repair the body and the patient should have a clear understanding of what is expected to rehabilitate the injury.

Some questions that may be helpful include the following:

  • Are there work or activity restrictions or limitations that need to be observed?
  • When can I expect to be able to return to normal daily activities?
  • When can I expect to be fully recovered?
  • Do I need to be reevaluated, and if so, when?

While it may take weeks for a sprain or strain to be completely healed, the time to return to activity may be much shorter. Many minor muscle strains resolve themselves in a few days. While the injured person can return to full activity relatively quickly, the muscle may not be completely healed and is less able to withstand excessive stress, and may still be more prone to future recurrent injury. Similarly, sprained joints may be functional in a couple of weeks but might take months to heal completely and return to full strength and stability.

Special situations

Some muscle strains take longer to heal than others due to their location and function.

Chest wall muscle strains

The muscles that help us to breathe operate much like bellows. The chest wall expands to suck air into the lungs. When injuries occur to the muscles of the chest wall, healing time may be measured in weeks, not days. The muscles are unable to rest since they are involved in taking in a breath every five to six seconds. When there is a chest wall injury, the pectoralis muscles that cover the front part of the chest and help the arms with lifting, the intercostal muscles that are located between the ribs, and the upper back muscles can all go into spasm.

Regardless of whether there is a broken or bruised rib or a strained muscle, attempts to take a deep breath may cause sharp pain as the chest wall moves and the damaged muscle is stretched. While an injured arm can be rested in a sling or crutches can be used to rest an injured leg, it is difficult to stop breathing. It means that 12-14 times a minute, the injured muscle is required to work and stretch. Each breath is painful and delays healing. Chest wall muscle strains may take weeks to heal.

While wrapping the chest with an ace bandage might help with the discomfort, that treatment option is not recommended. It is important to take deep breaths and expand the lung completely to prevent the most common complication of a chest wall injury, which is pneumonia, an infection of the lung.

Neck strains

Numerous muscles are required to keep the head optimally stable on the shoulders and to allow it to swivel in many directions. Injuries are common to the trapezius and sternomastoid muscles, the large muscles that do the major work of neck turning. Smaller muscles that attach to the bony prominences of the neck can also be strained.

Depending upon the injury, significant pain and spasms can occur that are long-lasting. Whiplash is a non-medical term that describes strains and sprains of the neck that occur with violent flexion-extension injuries. Many structures can be the source of pain, and treatment results depend upon which structure, from muscle to tendon to ligament to nerve, is involved.

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What is the prognosis of sprains and strains?

The goal of treating a strain or sprain is to return the patient to their normal level of physical activity. When that can be accomplished and the time frame for recovery depends upon the specific injury.

  • An arm muscle strain may resolve with rest, ice, compression, and elevation in one to two days, and a sprained ankle may take two to four weeks.
  • However, a torn knee ACL, which is a grade 3 sprain, may need surgery and months of physical therapy and rehabilitation.

It is important to discuss with a health care professional or therapist their expectations as to how long they think a specific injury will take to get better and what the goal is for recovery. An athlete being cared for in a sports medicine clinic may have different expectations for activities and return to play than a sedentary patient whose goal is to be able to perform basic functions of daily life.

Is it possible to prevent sprains and strains?

Putting the body to work requires that it be prepared for a specific activity.

  • Athletes routinely warm up before practice and competition, and that same philosophy of injury prevention can be applied to regular daily activities.
  • Stretching before work and gradually increasing the amount of effort and exertion may help prevent injured joints and muscles. Everybody is an athlete in their way, and it is just as important to warm up before shoveling snow, mowing the grass, or vacuuming, as it is before playing basketball or golf.
  • Moreover, exercises and stretches that strengthen the muscles that are used in routine activities can help maximize flexibility and minimize the risk of future injury.

A previous sprain or strain is a risk factor for another future injury to that particular area. Being certain that an injured body part is completely healed before stressing it again is essential to minimize that risk.

Where can people find more information about sprains and strains?

A healthcare professional can be an important resource for information regarding muscle and joint injuries. Physical therapists and chiropractors can help rehabilitate people with these injuries.

Local hospitals, county health departments, and health clubs will have literature and information about injury prevention and healthy lifestyles that may minimize the risk of a strain or sprain. They may also have exercise and stretching classes, including yoga and Pilates, to help with injury prevention.

References
American Academy of Orthopaedic Surgeons. "Sprains, Strains and Other Soft-Tissue Injuries." July 2015. <https://orthoinfo.aaos.org/en/diseases--conditions/sprains-strains-and-other-soft-tissue-injuries/>.

McPhee, S.J., M. Papdakis, and M.W. Rabow. Current Medical Diagnosis and Treatment, 50th ed. New York: McGraw Hill Medical, 2011.

Sherman, S.C. Simon's Emergency Orthopedics, 7th Ed. New York: McGraw Hill Education, 2014.