Lower extremity functional performance tests and their measurement properties in athletes: a systematic review and narrative synthesis

Objective To identify functional performance tests (FPTs) with potential to identify athletes at risk of lower extremity injury (LEI) and assess their measurement properties. Design Systematic review conducted in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses and PRISMA in Exercise, Rehabilitation, Sports Medicine and Sports Science guidance. Data sources Two-stage systematic search of Medline, Embase, Cumulative Index to Nursing and Allied Health Literature and SPORTDiscus databases from inception to 24 November 2023, supplemented by hand searching of reference lists, key journals and grey literature. Eligibility criteria Search 1 identified FPT predicting LEI in athletes aged >16 years competing at elite, pre-elite or collegiate levels and feasible in the field. Search 2 assessed measurement properties of identified FPT. COnsensus-based Standards for the selection of health Measurement INstruments risk of bias checklist and criteria for good measurement properties were applied, and evidence summarised using modified Grading of Recommendations, Assessment, Development and Evaluations guidelines. Results Fifty-nine studies evaluating 15 FPTs were included. Reliability (n=14), measurement error (n=11), structural validity/internal consistency (n=2), criterion validity (n=11), construct validity (n=5) and responsiveness (n=1) were assessed. No FPT demonstrated high certainty for measurement properties. Y-balance test (YBT) demonstrated moderate certainty for three properties (intrarater reliability, criterion validity and responsiveness). Knee to wall (KTW), single-leg squat (SLS), drop vertical jump (DVJ) and single hop for distance (SHFD) showed moderate certainty for two properties (reliability, intra/inter test-retest; criterion validity). Side hop, functional movement screen and landing error scoring system showed moderate certainty for one measurement property. Practicability assessment revealed poor reporting of time requirements and results production. Conclusion Moderate-certainty evidence supported reliability and validity of five FPTs (YBT, KTW, SLS, DVJ, SHFD) used to identify athletes at LEI risk. Studies with low bias and comprehensive practicability evaluations are lacking. PROSPERO registration number CRD42020188932.