Relative and Absolute Interrater Reliabilities of a Hand-Held Myotonometer to Quantify Mechanical Muscle Properties in Patients with Acute Stroke in an Inpatient Ward.

Jiang Li Zhao,Wai Leung Ambrose Lo,Le Li,Dong Feng Huang,Yu Rong Mao

doi:10.1155/2017/4294028

Abstract

Introduction The reliability of using MyotonPRO to quantify muscles mechanical properties in a ward setting for the acute stroke population remains unknown. Aims To investigate the within-session relative and absolute interrater reliability of MyotonPRO. Methods Mechanical properties of biceps brachii, brachioradialis, rectus femoris, and tibialis anterior were recorded at bedside. Participants were within 1 month of the first occurrence of stroke. Relative reliability was assessed by intraclass correlation coefficient (ICC). Absolute reliability was assessed by standard error of measurement (SEM), SEM%, smallest real difference (SRD), SRD%, and the Bland-Altman 95% limits of agreement. Results ICCs of all studied muscles ranged between 0.63 and 0.97. The SEM of all muscles ranged within 0.30–0.88 Hz for tone, 0.07–0.19 for decrement, 6.42–20.20 N/m for stiffness, and 0.04–0.07 for creep. The SRD of all muscles ranged within 0.70–2.05 Hz for tone, 0.16–0.45 for decrement, 14.98–47.15 N/m for stiffness, and 0.09–0.17 for creep. Conclusions MyotonPRO demonstrated acceptable relative and absolute reliability in a ward setting for patients with acute stroke. However, results must be interpreted with caution, due to the varying level of consistency between different muscles, as well as between different parameters within a muscle.

Highlights

The reliability of using MyotonPRO to quantify muscles mechanical properties in a ward setting for the acute stroke population remains unknown
Rectus femoris on the affected side has high consistency and agreement between the two measurements for tone, stiffness, and creep whereas moderate consistency was observed for decrement
Tibialis anterior has intraclass correlation coefficient (ICC) range within 0.65–0.91 which indicates moderate to very high consistency

Summary

Introduction

The reliability of using MyotonPRO to quantify muscles mechanical properties in a ward setting for the acute stroke population remains unknown. Since abnormal mechanical properties of these muscles might contribute to functional limitations and reduced mobility, changes in mechanical properties are routinely monitored as part of rehabilitation programs [6] Muscle mechanical properties such as tone and stiffness are clinically assessed subjectively by scoring resistance to passive motion on scales such as the modified Ashworth scale (MAS) or by manual palpation [7]. Other published studies have reported statistically significant differences in mechanical muscle properties between different age groups of women [15] and in mixed populations [16] between people with Parkinson’s disease and healthy individuals [17] and between people with chronic stroke and healthy individuals [18] when measured using a myotonometer. Existing evidence suggests that myotonometry is a valid technology to record the mechanical properties of muscles

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