Validity and reliability of three methods of stiffness assessment

Abstract

BackgroundStiffness is commonly assessed in relation to injury and athletic performance. The purpose of this research was to compare the validity and reliability of 3 in vivo methods of stiffness assessment using 1 cohort of participants.MethodsTo determine inter-day reliability, 15 female netballers were assessed for stiffness twice within 1 week using unilateral hopping (vertical stiffness), free oscillations of the calf, and myometry of various muscles of the triceps surae. To establish convergent construct validity, stiffness was compared to static and dynamic strength measurements.ResultsTest–retest stiffness results revealed that vertical stiffness produced moderate to high reliability results and myometry presented moderate to very high reliability. In contrast, the free oscillation technique displayed low to moderate reliability. Vertical stiffness demonstrated a significant correlation with rate of force development during a squat jump, whilst myometer stiffness measurements from 3 sites in the lower limb revealed significant correlations with isometric rate of force development. Further, significant negative correlations were evident between the eccentric utilisation ratio and various myometer stiffness results. No relationships were established between the free oscillation technique and any of the performance measurements.ConclusionThese results suggest that vertical stiffness and myometry are valid and reliable methods for assessing stiffness.

Myotonometry as a tool for determination of fatigue in the upper extremities of garment industry workers

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“…The values of stiffness are in the range of 150 N/m to 300 N/m, depending on the type of the muscle. The results of "myotonometric" measurement of workers in different occupations can be found in [6][7][8]. The aim of the study is to determine the fatigue of muscles during the work process in the garment industry.…”

Early structural and functional signature of 3‐day human skeletal muscle disuse using the dry immersion model

“…; Pruyn et al . ) reported an excellent interrater reliability with an interclass correlation of 0.81–0.98 on rectus femoris. From the oscillation acceleration signal, we investigated three parameters computed in real time by MyotonPRO software: dynamic stiffness, oscillation frequency and logarithmic decrement.…”

Effects of Sympathetic Conversation on Electroencephalogram, Stress, Anxiety-Depression, and Muscle Tone in Chronic Stroke Patients*

“…stiffness (N/m: Dynamic Stiffness), and the mean values were analyzed(Park et al, 2017). This device showed high to very high ICC values (.85-.94)(Pruyn et al, 2016). The measurement procedure involved pressing the device against the skin, after which the skin surface oscillation induced by the MyotonPRO was measured to verify the value of the mechanical variability(Bailey et al, 2013;Park et al, 2017).…”