British Athletics muscle injury classification
The British Athletics muscle injury classification (BAMIC/BAC) is a five-point MRI-based system that is based on extent and site. It has been primarily based on hamstring injuries but is used in other muscle injuries. The classification system has been shown to have moderate inter- and intra-rater agreeability . There is ongoing research on the usefulness of this classification system about prognostication for "return to play".
Classification
- grade 0
- grade 0a: focal neuromuscular injury with normal MRI
- grade 0b: generalized muscle soreness with normal MRI or MRI findings typical of delayed onset muscle soreness (DOMS)
- grade 1 (mild): high STIR signal that is <10% cross-section or longitudinal length <5 cm with <1 cm fiber disruption
- grade 2 (moderate): high STIR signal that is 10-50% cross-section; longitudinal length 5-15 cm with <5 cm fiber disruption
- grade 3 (extensive): high STIR signal that is >50% cross-section or longitudinal length >15 cm with >5 cm fiber disruption
- grade 4: complete tear
Grades 1-3 are subclassified depending on site:
- a: myofascial (peripheral)
- b: myotendinous junction / muscular
- c: tendinous
For grade 4 (complete tears), the distinction is only made between tears involving muscle versus those solely involving the tendon, as follows:
- grade 4: myofascial, muscular, or myotendinous
- grade 4c: tendinous
