High Density Surface Electromyography Activity of the Lumbar Erector Spinae Muscles and Comfort/Discomfort Assessment in Piano Players: Comparison of Two Chairs

Alejandra Aranceta-Garza; Alessandro Russo; Samuel D'Emanuele; Francesca Serafino; Roberto Merletti

doi:10.3389/fphys.2021.743730

High Density Surface Electromyography Activity of the Lumbar Erector Spinae Muscles and Comfort/Discomfort Assessment in Piano Players: Comparison of Two Chairs

Front Physiol. 2021 Dec 1:12:743730. doi: 10.3389/fphys.2021.743730. eCollection 2021.

Authors

Alejandra Aranceta-Garza¹, Alessandro Russo², Samuel D'Emanuele^{3

4}, Francesca Serafino^{2

5}, Roberto Merletti²

Affiliations

¹ Biomedical Engineering, School of Science and Engineering, University of Dundee, Dundee, United Kingdom.
² Laboratory for Engineering of the Neuromuscular System (LISiN), Department of Electronics and Telecommunications, Politecnico di Torino, Turin, Italy.
³ Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
⁴ School of Exercise and Sport Sciences, University of Turin, Turin, Italy.
⁵ Montecatone Rehabilitation Institute S.p.A., Imola, Italy.

Abstract

Introduction: At a professional level, pianists have a high prevalence of playing-related musculoskeletal disorders. This exploratory crossover study was carried out to assess and compare quantitatively [using high density surface electromyography (HDsEMG)], and qualitatively (using musculoskeletal questionnaires) the activity of the lumbar erector spinae muscles (ESM) and the comfort/discomfort in 16 pianists sitting on a standard piano stool (SS) and on an alternative chair (A-chair) with lumbar support and a trunk-thigh angle between 105° and 135°. Materials and Methods: The subjects played for 55 min and HDsEMG was recorded for 20 s every 5 min. For the quantitative assessment of the muscle activity, the spatial mean of the root mean square (RMS _ROA ) and the centroid of the region of activity (ROA) of the ESM were compared between the two chairs. For the qualitative assessment, musculoskeletal questionnaire-based scales were used: General Comfort Rating (GCR); Helander and Zhang's comfort (HZc) and discomfort (HZd); and Body Part Discomfort (BPD). Results: When using the A-chair, 14 out of 16 pianists (87.5%) showed a significantly lower RMS _ROA on the left and right side (p < 0.05). The mixed effects model revealed that both chairs (F = 28.21, p < 0.001) and sides (F = 204.01, p < 0.001) contributed to the mean RMS _ROA variation by subject (Z = 2.64, p = 0.004). GCR comfort indicated that participants found the A-Chair to be "quite comfortable," and the SS to be "uncomfortable." GCR discomfort indicated that the SS caused more numbness than the A-Chair (p = 0.05) and indicated the A-Chair to cause more feeling of cramps (p = 0.034). No difference was found on HZc (p = 0.091) or HZd (p = 0.31) between chairs. Female participants (n = 9) reported greater comfort when using the A-Chair than the SS (F = 7.09, p = 0.01) with respect to males. No differences between chairs were indicated by the BPD assessment. Conclusion: It is concluded that using a chair with lumbar support, such as the A-chair, will provide greater comfort, less exertion of the ESM and less discomfort than the standard piano stool.

Keywords: back muscles; high-density sEMG; musculoskeletal questionnaire; piano players; surface electromyography.