Table 5

Characteristics of included studies

StudyStudy designRisk factors examinedOutcome measuresSignificant risk factor identifiedStatistical figuresNon-significant potential risk factorsSport and sample size (with n injured)
Arnason et al3Prospective cohort studyAnthropometrics* flexibility, leg extension power, jump height, peak O2 uptake, joint stability and history of previous injuryQuestionnaire, peak O2 uptake, body composition, power testing, jump, flexibility, and ankle and knee stability tests and injury reports
  1. Previous groin injury

  2. Decreased hip Abd ROM

  3. Age (older players)

  1. OR=7.3, p=0.001

  2. OR=0.9, p=0.05

  3. OR=0.9, p=0.05

Body fat,
Peak O2 uptake
306 professional soccer players tested, 201 (82%) attained lower limb injuries, 13% were groin injuries
Engebretsen et al21Prospective cohort studyAnthropometrics*history of groin injury, function scores, clinical examination, and isometric groin strengthCounter-movement jumps, 40 m sprint tests, an isometric adductor strength test, a clinical examination and a questionnaire
  1. Previous groin injury

  2. Weak hip adductors

  1. OR=2.6, 95% CI 1.1 to 6.11

  2. OR=4.28, 95% CI 1.31–14.0

Countermovement jump test
40 m sprint test
Anthropometrics* Clinical examination†
Player experience
GrOS total score
508 amateur soccer players, 61 groin injuries were registered
Gabbe et al5Retrospective cohort studyAnthropometrics*demographic information and previous history of hip/groin injuryThe number of hip/groin injuries resulting in ≥1 missed ARF game, over 7 seasonsPrevious groin/hip injuryIRR=6.24
95% CI 4.43 to 8.77
500 ARF players, 159 (32%) sustained groin/hip injuries
Hagglund et al22Prospective cohort studyAnthropometrics* and injury dataInjury report sheet (injury location, severity, loss of match and training time, previous injuries) per playerPrevious groin/hip injuryHR=2.4
95% CI 1.2 to 4.6
Anthropometrics*525 elite soccer players tested over 2 seasons, 206 groin/hip injuries recorded
Le Gall et al23Prospective, observational cohort studyInvestigate injury according to biological maturity and chronological ageSkeletal maturity was measured using the Greulich-Pyle method (1959) with players injury (type, incidence, severity and distribution)Early maturing playersPost hoc=early (0.9) vs normal (0.44) vs late (0.08) maturing
Age233 players over 10 seasons, no figure of groin/hip injuries was available
O'Connor 12Prospective cohort studyAnthropometric data‡, Kinanthropometric data (sum of skinfolds and femur bone diameter), peak torque, work, power, endurance ratios and peak torque ratios of the hip abductors and adductors and knee flexors and extensors, hip abduction, adduction, internal and external hip rotation ROM, hamstring and groin flexibilityUse of a questionnaire for Anthropometric data, Kinanthropometric measures, A Cybex 340 isokinetic dynamometer, ROM measures, FABER test and Splits
  1. Abd and adduction with rotation peak torque

  2. Angle of adduction and abd with rotation peak torque

  3. Strength ratio of hip muscle groups

  4. Bilateral difference in extension peak torque

  5. Smaller femur diameter

  6. Higher BM

  7. Older age

  1. WL=0.94, p=0.02

  2. WL=0.76, p<0.001

  3. Not available

  4. Not available

  5. WL=0.89, p=0.001

  6. WL=0.96, p<0.05

  7. p<0.05

Body composition
Player experience
Peak torque, work, power, endurance ratios and peak torque ratios of the hip abductors and adductors in other positions
Hip abduction, adduction, internal and external hip rotation ROM
Groin flexibility
100 professional rugby league players, 23% sustained groin injuries
Verrall et al24Prospective cohort studyAnthropometrics*, hip joint internal and external ROM and incidence of groin painPlayer questionnaire, goniometer and team doctor record sheets
  1. Lower body weight

  2. Decreased total hip ROM

  1. IRR=0.92, p=0.004 95% CI 0.87 to 0.97

  2. IRR=0.9, p=0.03 95% CI 0.83 to 0.99

Dominant and non-dominant leg internal and external rotation
29 ARF players, 4 developed chronic groin injury
  • *Anthropometrics includes: height, weight, age and BMI.

  • †Clinical examination includes: external rotation in the hip joint (painful or not), functional testing of rectal abdominal muscles (painful or not) and strength of iliopsoas muscles (weak or not weak).

  • ‡Anthropometric data includes: height, weight, age, body composition, playing position, experience, ability level, weight training experience and emphasis on leg and hip muscles.

  • ARF, Australian Rules Football; BMI, body mass index; IRR, incident rate ratio; ROM, range of motion; WL, Wilks’ λ.