Screening Hamstring Injury Risk Factors Multiple Times in a Season Does Not Improve the Identification of Future Injury Risk

David A. Opar, Joshua D. Ruddy, Morgan D Williams, Nirav Maniar, Jack T. Hickey, Matthew N. Bourne, Tania Pizzari, Ryan G Timmins

Research output: Contribution to journalArticlepeer-review

20 Downloads (Pure)


PURPOSE: To determine if eccentric knee flexor strength and biceps femoris long head (BFlh) fascicle length were associated with prospective HSI in professional Australian Football players, and if more frequent assessments of these variables altered the association with injury risk.

METHODS: Across two competitive seasons, 311 Australian Football players (455 player seasons) had their eccentric knee flexor strength during the Nordic hamstring exercise and BFlh architecture assessed at the start and end of preseason and in the middle of the competitive season. Player age and injury history were also collected in preseason. Prospective HSIs were recorded by team medical staff.

RESULTS: Seventy-four player seasons (16%) sustained an index HSI. Shorter BFlh fascicles (<10.42 cm) increased HSI risk when assessed at multiple time points only (RR = 1.9; 95%CI = 1.2 to 3.0). Neither absolute (N) or relative ( eccentric knee flexor strength were associated with HSI risk, regardless of measurement frequency (RR range = 1.0 to 1.1), however between-limb imbalance (>9%) when measured at multiple time points was (RR = 1.8, 95%CI = 1.1 to 3.1). Prior HSI had the strongest univariable association with prospective HSI (RR = 2.9; 95%CI = 1.9 to 4.3). Multivariable logistic regression models identified a combination of prior HSI, BFlh architectural variables and between-limb imbalance in eccentric knee flexor strength as optimal input variables, however, their predictive performance did not improve with increased measurement frequency (Area under the curve = 0.681 to 0.726).

CONCLUSIONS: More frequent measures of eccentric knee flexor strength and BFlh architecture across a season did not improve the ability to identify which players would sustain a HSI.

Original languageEnglish
JournalMedicine and Science in Sports and Exercise
Issue number00
Early online date20 Sept 2021
Publication statusPublished - 20 Sept 2021


  • Australian Football
  • Hamstring Muscles
  • Wounds and Injuries
  • Risk factors
  • Prospective Study


Dive into the research topics of 'Screening Hamstring Injury Risk Factors Multiple Times in a Season Does Not Improve the Identification of Future Injury Risk'. Together they form a unique fingerprint.

Cite this