Relationship between three single-leg functional performance tests for netball noncontact knee injury prevention screening in uninjured female adult players

Context: Single-leg versus double-leg landing events occur the majority of the time in a netball match. Landings are involved in large proportions of netball noncontact knee injury events. Of all landing-induced anterior cruciate ligament injuries, most occur during single-leg landings. Knowledge of whether different single-leg functional performance tests (FPT) capture the same or different aspects of lower-limb motor performance will, therefore, inform clinicians’ reasoning processes and assist in netball noncontact knee injury prevention screening. Objective: To determine the correlation between the triple-hop-for-distance (THD), single-hop-for-distance (SHD), and vertical-hop (VH) for the right and left lower-limbs in adult female netball players. Design: Cross-sectional. Setting: Local community netball club. Participants: Twenty-three players (age 28.7±6.2 yr; height 171.6±7.0 cm; mass 68.2±9.8 kg). Interventions: Three measured trials (right and left) for, in order, THD, SHD, VH. Main Outcome Measures: Mean hop distance (percentage of leg-length (%LL)), Pearson’s inter-test correlation (r), coefficient of determination (r2). Results: Values (right, left, (mean±SD)) were: THD, 508.5±71.8%LL, 510.9±56.7 %LL; SHD, 183.4±24.6 %LL, 183.0±21.5 %LL; VH, 21.3±5.2 %LL, 20.6±5.0 %LL. All correlations were significant (P ≤ 0.05), r/r2 values (right, left) were: THD-SHD 0.91/0.83, 0.87/0.76; THD-VH, 0.59/0.35, 0.51/0.26; SHD-VH, 0.50/0.25, 0.37/0.17. A very large proportion of variance (76-83%) was shared between the THD and SHD. A small proportion of variance was shared between the THD and VH (25-35%) and SHD and VH (17-25%). Conclusion: The THD and SHD capture highly similar aspects of lower-limb motor performance. In contrast, the VH captures aspects of lower-limb motor performance different to the THD or SHD. Either the THD or SHD can be chosen for use within netball knee injury prevention screening protocols according to which is reasoned as most appropriate at a specific point-in-time. The VH, however, should be employed consistently alongside rather than in place of the THD or SHD.