Corpus3D

Conditions

Muscle strain

Mechanism
Tearing of muscle fibres under an eccentric load stretching the fibre too fast or too far. Biarticular muscles with many fast fibres are most vulnerable: the hamstrings, rectus femoris and gastrocnemius.
Recognition
Sudden sharp pain at an identifiable moment, then pain on stretching and on resisted contraction. Palpation gives a local painful point and sometimes a palpable gap.
Course
The site of the tear predicts recovery better than its size: the closer to the tendon, the slower. On return to sport the measure is not pain but strength at long muscle length.

Structures

Sources