Strains occur during or after a vigorous overstretching of a
muscle bundle that leads to an insidious development of pain
and tightness which is worse with use and better with rest.
Tears of the muscle belly tend to be partial, with sudden
onset of pain and partial loss of function. Often a tear
occurs with considerable bleeding which can lead to
remarkable hematomas, causing swelling at the site and
dissecting along tissue planes to create ecchymoses at
distant, uninvolved sites. Complete tears are more likely in
the tendinous part of the muscle, and produce immediate loss
of function, and retraction of the torn end, creating a
deformity and bulge.
What to do:
Obtain a history of the mechanism of injury, and test
individual muscle functions. A complete tear of a muscle
merits orthopedic consultation.
Even for a partial tear of a muscle belly, try to refine
the diagnosis to a specific muscle or muscle group, to help
exclude other possibilities.
For muscle strains, provide soft splinting, analgesics and
instruct the patient to apply warm moist compresses for
For muscle tears, construct a loose splint to immobilize
the injured part, and instruct the patient in rest,
elevation, and ice.
Warn the patient that partial tears can become complete,
and that blood will change color and percolate to the skin
at distan sites, where it does not imply additional injury.
Arrange for followup.
Some restrict the term "strain" for muscle injuries, and
"sprain" for ligament injuries. A complete tear of the
plantaris tendon in the leg is difficult to differentiate
from a partial tear of the gastrocmius muscle, but the
treatment for both is the same.