The Interday Reliability of Leg and Ankle Musculotendinous Stiffness Measures

Abstract

Two popular methods of assessing lower body musculotendinous stiffness include the hopping and oscillation tests. The disparity and paucity of reliability data prompted this investigation into leg musculotendinous stiffness (Kleg) and ankle musculotendinous stiffness (Kank) measures. Klegand Kankwere assessed on three separate occasions in 20 female subjects. Klegwas determined using bilateral hopping procedures conducted at 2.2 Hz and 3.2 Hz frequencies. Kankwas assessed by perturbation of the subject's ankle musculotendinous unit on an instrumented calf raise apparatus at 70% of maximum isometric force (MIF). Excellent reliability was produced for all Klegmeasures between all days, whereas Kankexhibited acceptable reliability after one session of familiarization. No relationship was evident between Klegand Kank. It was concluded that no familiarization session was required for Klegat the test frequencies and conditions tested, whereas at least one familiarization session was needed to ensure the reliable assessment of Kank.