Reproducibility and reliability of two kinds of soft tissue stiffness meter

In this study we assessed two models of soft tissue stiffness meter (TRY-ALL Corporation NEUTONE TDM-N1 and TDM-NA1; STSM-with alarm, and without alarm) for inter/intra-rater reproducibility and reliability. In Experiment 1, subjects comprising 21 physical therapists (PT) or occupational therapists (OT) measured the surface stiffness of a polyurethane test piece with known physical properties using the STSM with no alarm (NI). They each took 7 consecutive readings at the same site. In Experiment 2, 22 PT or OT used the same model of STSM with an alarm (NA1) to measure the stiffness of the same test piece at the same site. The intra-subject reproducibility was high: NI coefficient of variation % (CV) = 2.9 ± 1.3%; NA1, CV= 1.5 ± 0.4%. In addition, the inter-subject reliability was high; N1, Intraclass correlation coefficients: ICC (2.1) (2.7) =0.56, 0.9; NA1, ICC (2.1) (2.7) = 0.42, 0.83. Thus, it seems reasonable to conclude that STSM is a reliable and useful device for objective quantitative evaluation of soft tissue stiffness.