3D Medical Animation Depicting Strain-Tendon

A strain is an acute or chronic

soft tissue injury A soft tissue injury is the damage of muscles, ligaments and tendons throughout the body. Common soft tissue injuries usually occur from a sprain, strain (injury), strain, a one-off blow resulting in a contusion or overuse of a particular part of ...

that occurs to a

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

tendon A tendon or sinew is a tough band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...

, or both. The equivalent injury to a

ligament A ligament is a type of fibrous connective tissue in the body that connects bones to other bones. It also connects flight feathers to bones, in dinosaurs and birds. All 30,000 species of amniotes (land animals with internal bones) have liga ...

is a

sprain A sprain is a soft tissue injury of the ligaments within a joint, often caused by a sudden movement abruptly forcing the joint to exceed its functional range of motion. Ligaments are tough, inelastic fibers made of collagen that connect two or ...

. Generally, the muscle or tendon overstretches and partially tears, under more physical stress than it can withstand, often from a sudden increase in duration, intensity, or frequency of an activity. Strains most commonly occur in the foot, leg, or back. Immediate treatment typically used to include four steps abbreviated as R.I.C.E. (rest, ice, compression, elevation) before the role of inflammation was found to be helpful.

Signs and symptoms

Typical signs and

symptom Signs and symptoms are diagnostic indications of an illness, injury, or condition. Signs are objective and externally observable; symptoms are a person's reported subjective experiences. A sign for example may be a higher or lower temperature ...

s of a strain include

pain Pain is a distressing feeling often caused by intense or damaging Stimulus (physiology), stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sense, sensory and emotional experience associated with, or res ...

, functional loss of the involved structure,

muscle weakness Muscle weakness is a lack of muscle strength. Its causes are many and can be divided into conditions that have either true or perceived muscle weakness. True muscle weakness is a primary symptom of a variety of skeletal muscle diseases, includ ...

contusion A bruise, also known as a contusion, is a type of hematoma of tissue, the most common cause being capillaries damaged by trauma, causing localized bleeding that extravasates into the surrounding interstitial tissues. Most bruises occur clo ...

, and localized

inflammation Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...

. A strain can range from mild overstretching to severe tears, depending on the extent of injury.

Cause

A strain can occur as a result of improper body mechanics with any activity (e.g.,

contact sport A contact sport is any sport where physical contact between competitors, or their environment, is an integral part of the game. For example, gridiron football. Contact may come about as the result of intentional or incidental actions by the playe ...

s, lifting heavy objects) that can induce mechanical trauma or injury. Generally, the muscle or tendon overstretches and is placed under more physical stress than it can withstand. Strains commonly result in a partial or complete tear of a tendon or muscle, or they can be severe in the form of a complete tendon rupture. Strains most commonly occur in the

foot The foot (: feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is an organ at the terminal part of the leg made up o ...

leg A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element cap ...

, or back. Acute strains are more closely associated with recent mechanical trauma or injury. Chronic strains typically result from repetitive movement of the muscles and tendons over a long period of time. Degrees of Injury (as classified by the

American College of Sports Medicine The American College of Sports Medicine (ACSM), headquartered in Indianapolis, Indiana, is a sports medicine and exercise science membership organization. Founded in 1954, ACSM holds conferences, publishes books and journals, and offers certif ...

): * First degree (mildest) – little tissue tearing; mild tenderness; pain with full range of motion. * Second degree – torn muscle or tendon tissues; painful, limited motion; possibly some swelling or depression at the spot of the injury. * Third degree (most severe) – limited or no movement; severe acute pain, though sometimes painless straight after the initial injury To establish a uniform definition amongst healthcare providers, in 2012 a Consensus Statement on suggested new terminology and classification of muscle injuries was published. The classifications suggested were: : The major difference suggested was the use of "indirect" muscle injury verse "grade 1" to provide subclassifications when advanced images were negative. Indirect Muscle Injury FUNCTIONAL (Negative MSK US & MRI) * Type 1: Overexertion-related Muscle Disorder ** Type 1a: Fatigue induced ** Type 1b: DOMS • Type 2: Neuromuscular muscle disorder ** Type 2a: Spine-Related ** Type 2b: Muscle-Related STRUCTURAL MUSCLE INJURY (Positive MSK US & MRI) • Type 3: Partial Muscle Tear • Type 4: (Sub) total tear DIRECT MUSCLE INJURY • Bump or Cut: Contact-related

Risk factors

Although strains are not restricted to athletes and can happen while doing everyday tasks, people who play sports are more at risk for developing a strain. It is common for an

injury Injury is physiological damage to the living tissue of any organism, whether in humans, in other animals, or in plants. Injuries can be caused in many ways, including mechanically with penetration by sharp objects such as teeth or with ...

to develop when there is a sudden increase in duration, intensity, or frequency of an activity.

Treatment

The first-line treatment for a muscular strain in the

acute phase Acute may refer to: Language * Acute accent, a diacritic used in many modern written languages * Acute (phonetic), a perceptual classification Science and mathematics * Acute angle ** Acute triangle ** Acute, a leaf shape in the glossary of leaf m ...

include five steps commonly known as P.R.I.C.E. * Protection: Apply soft padding to minimize impact with objects. * Rest: Rest is necessary to accelerate healing and reduce the potential for re-injury. * Ice: Apply ice to induce

vasoconstriction Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, in particular the large arteries and small arterioles. The process is the opposite of vasodilation, the widening of blood vesse ...

, which will reduce blood flow to the site of injury. Never ice for more than 20 minutes at a time. * Compression: Wrap the strained area with a soft-wrapped bandage to reduce further

diapedesis In immunology, leukocyte extravasation (also commonly known as leukocyte adhesion cascade or diapedesis – the passage of cells through the intact vessel wall) is the movement of leukocytes (white blood cells) out of the circulatory system ( ex ...

and promote lymphatic drainage. * Elevation: Keep the strained area as close to the level of the heart as is possible in order to promote venous blood return to the systemic circulation. Immediate treatment is usually an adjunctive therapy of

NSAID Non-steroidal anti-inflammatory drugs (NSAID) are members of a therapeutic drug class which reduces pain, decreases inflammation, decreases fever, and prevents blood clots. Side effects depend on the specific drug, its dose and duration of ...

s and

Cold compression therapy Cold compression therapy, also known as hilotherapy, combines two of the principles of rest, ice, compression, elevation to reduce pain and swelling from a sports or activity injury to soft tissues and is recommended by orthopedic surgeons foll ...

. Cold compression therapy acts to reduce swelling and pain by reducing

leukocyte extravasation In immunology, leukocyte extravasation (also commonly known as leukocyte adhesion cascade or diapedesis – the passage of cells through the intact vessel wall) is the movement of leukocytes (white blood cells) out of the circulatory system (ext ...

into the injured area. NSAIDs such as

Ibuprofen/paracetamol Ibuprofen/paracetamol, sold under the brand name Combogesic among others, is a fixed-dose combination of two medications, ibuprofen, a non-steroidal anti-inflammatory drug (NSAID); and paracetamol (acetaminophen), an analgesic and antipyretic. ...

work to reduce the immediate inflammation by inhibiting

Cox-1 Cyclooxygenase 1 (COX-1), also known as prostaglandin-endoperoxide synthase 1 ( HUGO PTGS1), is an enzyme that in humans is encoded by the ''PTGS1'' gene. In humans it is one of three cyclooxygenases. History Cyclooxygenase (COX) is the centr ...

and

Cox-2 Cyclooxygenase-2 (COX-2), also known as prostaglandin-endoperoxide synthase 2 ( HUGO PTGS2), is an enzyme that in humans is encoded by the ''PTGS2'' gene. In humans it is one of three cyclooxygenases. It is involved in the conversion of arachid ...

enzymes, which are the enzymes responsible for converting

arachidonic acid Arachidonic acid (AA, sometimes ARA) is a polyunsaturated omega−6 fatty acid 20:4(ω−6), or 20:4(5,8,11,14). It is a precursor in the formation of leukotrienes, prostaglandins, and thromboxanes. Together with omega−3 fatty acids an ...

into

prostaglandin Prostaglandins (PG) are a group of physiology, physiologically active lipid compounds called eicosanoids that have diverse hormone-like effects in animals. Prostaglandins have been found in almost every Tissue (biology), tissue in humans and ot ...

. However, NSAIDs, including

aspirin Aspirin () is the genericized trademark for acetylsalicylic acid (ASA), a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and inflammation, and as an antithrombotic. Specific inflammatory conditions that aspirin is ...

and ibuprofen, affect platelet function (this is why they are known as "blood thinners") and should not be taken during the period when tissue is bleeding because they will tend to increase blood flow, inhibit clotting, and thereby increase bleeding and swelling. After the bleeding has stopped, NSAIDs can be used with some effectiveness to reduce inflammation and pain. A new treatment for acute strains is the use of platelet rich plasma (PRP) injections which have been shown to accelerate recovery from non-surgical muscular injuries. It is recommended that the person injured should consult a medical provider if the injury is accompanied by severe pain, if the limb cannot be used, or if there is noticeable tenderness over an isolated spot. These can be signs of a broken or

fractured bone A bone fracture (abbreviated FRX or Fx, Fx, or #) is a medical condition in which there is a partial or complete break in the continuity of any bone in the body. In more severe cases, the bone may be broken into several fragments, known as a ''c ...

, a

, or a complete muscle tear.Neustaedter, Randy
"Natural Treatment for Injuries"
Retrieved 5 December 2020.

References

External links