Base Rates, Better Reasons to Screen and the Nordic Hamstring Exercise

Using the WHO bacon and colorectal cancer example, the speaker explains base rate neglect. In this cohort the pre-test chance of a hamstring injury is about 11%, and an odds ratio of 1.37 for eccentric strength moves it to about 14.6%. Strength differences were at most about 7 Nm, with effect sizes under 0.3. Strength tests measure continuous performance rather than giving a yes or no answer like a pivot shift test, which is why they work poorly for prediction. Screening still has value for finding current musculoskeletal problems and setting a performance baseline: about one in three screened players needed some follow-up. The part closes on the Nordic hamstring exercise, from early studies in 1994 and 2011 to work suggesting reductions of up to 67.5% in hamstring injuries, and on how load, match frequency, coaching and staff continuity shape injury risk in a team.