Table 1

Summary of study characteristics

First authorStudy design; surveillance periodNumber of participants, gender, age (mean±SD) yearsLevel of competition, sport(s)Index injury typeIndex injury context(s)Subsequent injury typeSubsequent injury context(s)Statistical analysis
Bourne47Prospective cohort;
one season		178 males (22.6±3.8)Elite (Super 15), subelite (QRU), and under-19 premier grade rugby unionACL injury, hamstring, quadriceps or calf strain injuries and chronic groin painAthlete self-report, clinical examinationAcute hamstring injurySports incapacity, clinical examinationUnivariate RR, multivariate logistic regression
Brooks52Retrospective cohort;
90 days following concussion		257 male and females (exposed group 19.8±1.3; unexposed group 19.9±1.3)NCAA Division I (variety of sports)ConcussionClinical examinationLower extremity musculoskeletal injuryClinical examinationConditional logistic regression
Hagglund53Prospective cohort;
nine full seasons (mean 2.3±1.7)		1401 males (25.8±4.5)Elite (UEFA) soccerAdductor, hamstring, quadriceps or calf muscle strainSports incapacityAdductor, hamstring, quadriceps or calf muscle strainSports incapacitySimple Cox regression, and multiple Cox regression
Koulouris32Prospective cohort;
one season		41 males (single hamstring injury 24.0±3.8; repeat hamstring injury 25.5±3.8)Elite (AFL) Australian footballACL injuryClinical examinationHamstring injury (single or recurrent)Sports incapacity, clinical examinationχ2 analysis and univariate logistic regression
Nilstad49Prospective cohort;
one season		173 females (21.5±4.1)Elite (Toppserien) soccerACL, knee, ankle, or hamstring injuriesAthlete self-report, sports incapacityLower extremity injuriesSports incapacityGEE, multivariate analysis including the bootstrap method
Opar50Prospective cohort;
one season		210 males (23.3±3.7)Elite (AFL) Australian footballACL injury, hamstring, quadriceps or calf strain injuries, or chronic groin painClinical examinationHamstring injurySports incapacity, clinical examinationUnivariate RR analysis, multivariate logistic regression
Orchard51Prospective cohort;
11 seasons		205 males (26.1±4.2)First class (Australia) fast bowlers in cricketLumbar stress fractureSports incapacityGroin, hamstring, quadriceps or calf strains, knee cartilage injuries, ankle sprains/joint injuriesSports incapacityUnivariate RR
Orchard29Prospective cohort;
eight seasons		1607 males (23.5)Elite (AFL) and subelite (second grade AFL) Australian footballHamstring, quadriceps or calf strainsSports incapacity, clinical examinationHamstring, quadriceps or calf strainsSports incapacity, clinical examinationForward stepwise logistic regression
Verrall30Prospective cohort;
one season		114 males (21.6±3.4)Elite (AFL) and subelite (SANFL) Australian footballSevere knee injury, groin injury, severe back injury or posterior thigh injurySports incapacity, clinical examinationHamstring injurySports incapacityFisher’s exact test, multivariable regression
Walden31Prospective cohort;
one season		310 males (25.8±4.5)Elite (Swedish professional league) soccerACL injuryAthlete self-report, clinical examinationNew knee injurySports incapacityCox proportional hazards regression
Kramer33Case–control; not stated66 females (case 21.0±2.1; control 19.6±1.3)Non-specified sport or level of competitionAnkle sprainAthlete self-reportACL reconstructionClinical examinationχ2 analysis
Lynall48Case–control;
2 years (±1 year of concussion)		102 male and females (case 20.0±1.2; control 20.5±1.3)NCAA Division I (variety of sports)ConcussionClinical examinationAcute lower extremity musculoskeletal injuryClinical examinationIRR

  • AFL, Australian Football League; GEE, general estimating equations; IRR, injury rate ratio; NCAA, National Collegiate Athletic Association; QRU, Queensland Rugby Union; RR, relative risk; SANFL, South Australian National Football League.