Hamstring Strain Grade on MRI and Return to Play in Elite Australian Cricket Players
Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine · 2026
Higher-grade and tendon-involving hamstring strains took longer to return in elite cricketers, but imaging likely influenced the very management it's being used to predict.
The paper
Retrospective cohort study, n=843 contracted elite Australian cricketers (478 male, 365 female), 141 MRI-confirmed hamstring strains over 13.5 seasons.
What they found
Across the 13.5-season study, 141 MRI-confirmed hamstring strains were recorded (3.2 per 100 players per season overall, but male incidence was roughly 4x female: 4.5 vs 1.2 per 100 players per season). Biceps femoris was the muscle most often injured (63%), and grade 2c (BAMIC grade 2, intramuscular tendon subtype) was the single most frequent injury category (27%). Across all grades, players were unavailable a median 22 days (IQR 15-38) and missed 3 matches (1-6); numeric grade 2-3 injuries ran significantly longer than grade 1 (P=0.004 and P=0.007), and tendon-involving injuries (BAMIC subtype b/c) ran longer than non-tendon (subtype a) injuries (P=0.002). Among pace bowlers specifically, those with a tendon-involving (subtype b/c) strain were unavailable longer than other players with the same subtype grouping (P=0.046).
Study design
Retrospective cohort study using prospectively collected injury surveillance and MRI data from elite Australian cricket, n=843 contracted players (141 injuries analysed), spanning 13.5 seasons. This sits as cohort/observational evidence, useful for prognosis but not causal inference.
Methodology
This relies on routinely collected surveillance data and clinician-coded MRI grading (BAMIC system), so detection and classification depend on consistent scan timing and reader agreement which aren't detailed here. The authors themselves flag the key circularity: MRI findings may have influenced return-to-play decisions, so the association between grade and time out could partly reflect clinician caution rather than true biological healing time. No confounder adjustment (age, prior injury, rehab protocol, match importance) is reported, and with only 141 injuries split across multiple grade and position subgroups, several comparisons (especially the pace bowler P=0.046) are likely underpowered and vulnerable to multiple-comparison inflation.
The appraisal
The grade-outcome and tendon-involvement associations are statistically significant, clinically plausible, and consistent with prior BAMIC literature from other sports, and the sample (141 MRI-confirmed strains across 13.5 elite seasons) is large for this injury type, so this is genuinely useful descriptive and prognostic signal rather than a preliminary curiosity. The caveat is real but shouldn't be overweighted: effect sizes (actual day differences between grades) aren't reported in the abstract, only p-values, so clinicians can't judge magnitude from this alone, and the retrospective design can't fully separate true biological prognosis from management bias, since clinicians likely held higher-grade or tendon-involved injuries out longer partly because of the imaging itself, a limitation the authors themselves flag.
The gap
The abstract gives no actual median day or match differences between grades or tendon-involved vs not, only p-values; without those numbers and without adjustment for confounders or blinding of return-to-play decisions to MRI grade, it's hard to know how much of this is prognosis versus self-fulfilling management.
Landmark context
This extends the body of work using the British Athletics Muscle Injury Classification (BAMIC), originally validated by Pollock et al. in athletics populations, into a cricket-specific context, and aligns with prior findings that intramuscular tendon involvement predicts longer recovery across sports.
What to do Monday
Clinicians working with cricketers can use MRI grade and tendon involvement as a rough prognostic flag for a longer, more variable return to play, particularly in pace bowlers, but should not treat this as a precise day-count predictor given the acknowledged circularity between imaging and management decisions.
In practice
This applies to any cricketer, but especially pace bowlers, with an MRI-confirmed hamstring strain, particularly grade 2-3 or tendon-involving (BAMIC subtype b/c) injuries. Monday-practical change: stop quoting a single expected day-count and instead use this paper's spread (median 22 days, IQR 15-38, longer and more variable once the tendon or higher numeric grade is involved) as the honest range to set expectations with the athlete, then gate the actual RTP decision on serial functional testing rather than the MRI grade alone, since the grade likely already influenced how long the player was held out (the circularity the authors flag). In the clinic, baseline a Single leg hamstring bridge at diagnosis and re-test through rehab so progression is criterion-based; on the S&C floor, treat pace bowlers with tendon-involving or grade 2-3 strains as needing an individualised, extended bowling workload build-back rather than a standard template, with volume and intensity progressed against test results and pain-free eccentric tolerance, not the calendar. Caveat: these are median figures from a mixed elite cricket cohort, not a validated prediction rule, so don't present them to an athlete as a guarantee of their own timeline.
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