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, a one-off blow resulting in a contusion or overuse of a particular part of the body. Soft ti ...
that occurs to a
muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...
,
tendon
A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...
, or both. The equivalent injury to a
ligament is a
sprain.
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 includes five steps abbreviated as
P.R.I.C.E.: protection, rest, ice, compression, elevation.
Signs and symptoms
Typical
signs and
symptoms of a strain include
pain, functional loss of the involved structure,
muscle weakness,
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 clos ...
, and localized
inflammation
Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...
. 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
Contact sports are sports that emphasize or require physical contact between players. Some sports, such as mixed martial arts, are scored on impacting an opponent, while others, including rugby football, gridiron football and Australian rules fo ...
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,
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 ca ...
, 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):
* 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 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-phase proteins (APPs) are a class of proteins whose concentrations in blood plasma either increase (positive acute-phase proteins) or decrease (negative acute-phase proteins) in response to inflammation. This response is called the ''acute-p ...
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 vess ...
, 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
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 out of the circulatory system and towards the site of tissue damage o ...
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 follo ...
. Cold compression therapy acts to reduce swelling and pain by reducing
leukocyte extravasation
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 out of the circulatory system and towards the site of tissue damage or ...
into the injured area. NSAIDs such as
Ibuprofen/paracetamol
Ibuprofen/paracetamol, sold under the brand name Combiflam among others, is a fixed-dose combination
A combination drug or a fixed-dose combination (FDC) is a medicine that includes two or more active ingredients combined in a single dosag ...
work to reduce the immediate inflammation by inhibiting
Cox-1
Cyclooxygenase 1 (COX-1), also known as prostaglandin G/H synthase 1, prostaglandin-endoperoxide synthase 1 or prostaglandin H2 synthase 1, is an enzyme that in humans is encoded by the ''PTGS1'' gene. In humans it is one of two cyclooxygenases.
...
and
Cox-2
Prostaglandin-endoperoxide synthase 2 (prostaglandin G/H synthase and cyclooxygenase) (The HUGO official symbol is PTGS2; HGNC ID, HGNC:9605), also known as cyclooxygenase-2 or COX-2, is an enzyme that in humans is encoded by the ''PTGS2'' gene ...
enzymes, which are the enzymes responsible for converting
arachidonic acid into
prostaglandin. However, NSAIDs, including
aspirin
Aspirin, also known as acetylsalicylic acid (ASA), is a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and/or inflammation, and as an antithrombotic. Specific inflammatory conditions which aspirin is used to treat inc ...
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
sprain, or a complete muscle tear.
[Neustaedter, Randy]
"Natural Treatment for Injuries"
Retrieved 5 December 2020.
See also
*
Achilles tendon rupture
Achilles tendon rupture is when the Achilles tendon, at the back of the ankle, breaks. Symptoms include the sudden onset of sharp pain in the heel. A snapping sound may be heard as the tendon breaks and walking becomes difficult.
Rupture typica ...
*
Pulled hamstring
Straining of the hamstring, also known as a pulled hamstring, is defined as an excessive stretch or tear of muscle fibers and related tissues. Hamstring injuries are common in athletes participating in many sports. Track and field athletes are ...
*
Repetitive strain injury
A repetitive strain injury (RSI) is an injury to part of the musculoskeletal or nervous system caused by repetitive use, vibrations, compression or long periods in a fixed position. Other common names include repetitive stress disorders, cumula ...
References
External links
{{DEFAULTSORT:Strain (Injury)
Dislocations, sprains and strains
Muscular disorders