March 2021

Validity and reliability of myotonometry for assessing muscle viscoelastic properties in patients with stroke: a systematic review and meta‑analysis

Authors: Maria‑Isabel Garcia‑Bernal, Alberto Marcos Heredia‑Rizo, Paula Gonzalez‑Garcia*, Maria‑Dolores Cortes‑Vega & Maria Jesus Casuso‑Holgado

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Department of Physical Therapy, Faculty of Nursing, Physiotherapy and Podiatry, University of Sevilla, Sevilla, Spain

Journal: Nature - Scientific Reports - March 2021, Volume 11, Article no. 5062 (DOI: 10.1038/s41598-021-84656-1)

There is a lack of consensus about the measurement of the muscle viscoelastic features in stroke patients. Additionally, the psychometric properties of the most commonly used clinical tools remain controversial.

Our objective is to investigate the validity and reliability of myotonometry to assess viscoelastic muscle features in stroke survivors. Pubmed, PEDro, Scopus and Cinahl were systematically searched to include studies reporting the psychometric properties of myotonometric devices used in people after stroke. The QUADAS-2 and the COSMIN checklists were used to assess the methodological quality of the studies and the psychometric properties of myotonometry.

Nine studies were included in the qualitative synthesis and data from five of these were pooled in a meta-analysis. Overall, low to moderate risk of bias and applicability concerns were observed. Pooled data from intra-rater reliability for muscle tone showed a mean coefficient of correlation of 0.915 (95% CI: 0.880– 0.940, I 2 = 69.2%) for upper limbs, and a mean coefficient of 0.785 (95%CI: 0.708–0.844, I 2 = 4.02%) for lower limbs.

Myotonometry seems to be a valid and reliable complementary tool to assess muscle viscoelastic properties in stroke survivors, although definite conclusions about concurrent validity need further research.

Myotometry seems to be a valid and reliable complementary tool when assessing muscle viscoelastic properties in stroke survivors. It is relatively easy and quick to administer, highly objective, and the devices are portable. The clinical interpretation of the different muscle parameters could help to quantify the spastic post-stroke condition.

Future research should focus on the validation of myotonometric devices using biomechanical and neurophysiological measurements as reference standards and analyse the inter-rater absolute and relative reliability for upper and lower limbs assessment. It would also be advisable to compare the psychometric properties of the different myotonometric devices between acute, subacute and chronic stroke patients. Finally, these studies need to provide reports on clear and reproducible protocols.