Library · Disease
Muscle strain
Make it clearer
A muscle strain is what people commonly call a pulled muscle. It is a twist, a pull, or a tear that can involve three sites: the muscle, the tendon, which is the cord that anchors the muscle to the bone, or the musculotendinous junction, the exact point where one becomes the other.
It most often results from a specific combination: the muscle is shortening to generate force, which is called a concentric contraction, and at the same time something forcibly stretches it in the opposite direction. The muscle pulls while something stretches it, and it gives way at the junction with the tendon, which is the site injured most often.
Severity varies widely. It can remain a mild overstretch, or it can progress to a partial or complete tear. In grade 3 the musculotendinous unit ruptures completely, with severe pain and swelling and loss of function, meaning that part stops working.
In brief
A muscle strain is a twist, a pull, or a tear of the muscle, the musculotendinous junction, or the tendon.
Most often the muscle is forcibly stretched while it contracts concentrically; the site injured most often is the musculotendinous junction.
The muscle pulls while something stretches it, and it gives way at the junction.
It ranges from mild overstretching to a partial or complete tear; in grade 3 the musculotendinous unit ruptures, with severe pain and swelling and loss of function.
Sources (3)
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of HealthSports Injuries: Sprains and Strains, NIAMSPublished
- National Center for Biotechnology Information, StatPearls PublishingAdductor Strain, StatPearlsPublished
- National Center for Biotechnology Information, StatPearls PublishingHamstring Injury, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated