Estimation of vastus intermedius electromyography: Comparison of three methods and their impact on the knee isometric extension moment predicted by an EMG-Driven model

Article type: Research Article

Authors: de Oliveira, Viviane B.^a | de Oliveira, Liliam F.^{a; b} | Menegaldo, Luciano L.^{a; *}

Affiliations: [a] Biomedical Engineering Program, COPPE, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil | [b] School of Physical Education and Sports, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil

Correspondence: [*] Corresponding author: Luciano L. Menegaldo, Biomedical Engineering Program, COPPE, Federal University of Rio de Janeiro, Av. Horácio Macedo 2030, Bloco H-338, 21941-914, Rio de Janeiro, RJ, Brazil. E-mail: lmeneg@peb.ufrj.br.

Abstract: BACKGROUND: Estimations of deep muscles electromyography (EMG) with surface electrodes can be usually performed only indirectly. OBJECTIVE: To investigate the impact of using different approaches for estimating vastus intermedius EMG on the moment sharing patterns among quadriceps femoris components (QF), obtained with an EMG-Driven model, as well as on the joint total moment estimation accuracy, by comparing the calculated knee moment with isometric dynamometer measurements. METHODS: Extensor knee moment and surface isometric EMGs from the four QF components were collected synchronously with knee moment from an isokinetic dynamometer, with the knee flexed at 80∘ and moment level at 40% of the maximum. Neuromuscular excitations u⁢(t) for each QF were derived from the EMGs. Three different estimates of vastus intermedius excitation uVI⁢(t) were tested: (1) surface electrodes on the exposed portion of vastus intermedius; (2) average between vastus lateralis and vastus medialis; and (3) a regression equation to estimate VI EMG from the other QF components. RESULTS: No statistical differences were found among the relative moments, excitation signals, and estimation accuracy by using the three methods. CONCLUSIONS: The average between vastus lateralis and vastus medialis is the recommended choice for being the simplest one.

Keywords: EMG-Driven muscle models, vastus intermedius, knee muscles, joint moment

DOI: 10.3233/IES-182167

Journal: Isokinetics and Exercise Science, vol. 26, no. 4, pp. 299-306, 2018