Sensor-Based Assessment of Quadriceps EMG-Amplitude-to-Torque Ratios at Different Knee Angles: An Exploratory Cross-Sectional Study.

Zhaoxiang Zhang, Małgorzata Tomicka, Xiaodan Guo, Mingmao Li, Marcin Krawczynski, Piotr Aschenbrenner, Adam Kawczyński

Abstract read

In one paragraph

Article in Sensors (Basel, Switzerland), 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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5 · Who and what money

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7 authors.

Zhaoxiang ZhangDoctoral School, Gdansk University of Physical Education and Sport, Kazimierza Górskiego Street 1, 80-336 Gdansk, Poland.ORCID 0009-0000-1970-7901

Małgorzata TomickaDepartment of Biomechanics and Sport Engineering, Gdansk University of Physical Education and Sport, Kazimierza Górskiego Street 1, 80-336 Gdansk, Poland.ORCID 0009-0001-8054-2461

Xiaodan GuoDoctoral School, Gdansk University of Physical Education and Sport, Kazimierza Górskiego Street 1, 80-336 Gdansk, Poland.ORCID 0009-0006-7687-7329

Mingmao LiDoctoral School, Gdansk University of Physical Education and Sport, Kazimierza Górskiego Street 1, 80-336 Gdansk, Poland.ORCID 0009-0007-9060-3006

Marcin KrawczynskiDepartment of Biomechanics and Sport Engineering, Gdansk University of Physical Education and Sport, Kazimierza Górskiego Street 1, 80-336 Gdansk, Poland.ORCID 0000-0002-8515-234X

Piotr AschenbrennerDepartment of Biomechanics and Sport Engineering, Gdansk University of Physical Education and Sport, Kazimierza Górskiego Street 1, 80-336 Gdansk, Poland.ORCID 0000-0003-1307-6621

Adam KawczyńskiFaculty of Medicine, Wrocław University of Science and Technology, 50-370 Wrocław, Poland.ORCID 0000-0001-7840-3799

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Surface electromyography (sEMG) normalized to mechanical output can describe electrical activation amplitude relative to torque, but such ratios should not be interpreted automatically as neuromuscular efficiency. This exploratory cross-sectional study compared quadriceps activation-to-torque ratios at 45° and 75° knee flexion and examined hypothesis-generating associations with countermovement jump (CMJ) outcomes. Seventeen participants performed two brief unilateral maximal isometric knee-extension trials at each angle. Wireless sEMG from the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) and Biodex torque were acquired separately and manually matched by participant, knee angle, and test set. Ratios were calculated as Noraxon-exported mean EMG amplitude divided by Biodex average peak torque. Ratios were higher at 45° than at 75° for VL (mean difference = 0.74 μV/(N·m), BCa 95% CI: 0.34-1.34; Holm-adjusted

Indexed as

ElectromyographyKneeKnee JointQuadriceps MuscleAdultCross-Sectional StudiesFemaleHumansMaleTorqueYoung Adultactivation-to-torque ratioBiodexcountermovement jumpdynamometryknee extensionneuromuscular assessmentOptoJumpsensor-based assessmentsurface electromyographywireless EMG

Identifiers

PMID42515451

DOI10.3390/s26144568

PMCPMC13416507

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