Background Proprioception (joint position sense (JPS), kinaesthesia, force sense (FS)) is of interest in knee injury prevention. Recent work reports existing knee proprioception tests are inadequate relative to gaining better understanding of knee functional joint stability and injury aetiology.
Objective To determine critical psychometric properties of a new knee extension FS test in uninjured, adult, male football players. Hypotheses: 1. the test would demonstrate good reliability; 2. there would be no between-limb significant differences.
Design Between-day (D1/D2) repeated measures.
Setting University sensorimotor control laboratory.
Participants Twelve university team players (age (mean±SD) 21.1±1.5 years; height 177.5±9.3 cm; mass 77.1±15.4 kg) participated.
Interventions Players were seated on an isokinetic dynamometer set to isometric mode, the knee flexed 45°. A knee extension target trial-reproduction trial sequence was repeated five times, FS measured in Newtons (N), between-trial differences designated absolute error (AE), average AE used for analyses. Limb order was randomized for D1 and repeated D2.
Main Outcome Measures Systematic error (paired t-test; Cohen's d (d)); relative reliability (ICC 2,k); absolute reliability (standard error of measurement (SEM)); measurement change needed to detect true physiological differences (minimal detectable difference (MDD)); between-limb differences (D2 values; paired t-test).
Results There were no significant differences between D1 and D2 values for either limb (P>0.90; d<0.03). The ICC (2,k), SEM and MDD were: right=0.81, 3.3N, 9.1N; left=0.78, 3.8N and 10.4N. There were no significant between-limb differences (P=0.75).
Conclusions There was no systematic error. The FS test demonstrated good reliability. The measurement error and change needed to detect true physiological change were established. There were no between-limb differences. The knee extension FS test offers a new knee proprioception test that can be used in studies of knee functional joint stability and injury aetiology in adult male football players.