Quadriceps neuromuscular function in women with patellofemoral pain: Influences of the type of the task and the level of pain
journal contributionposted on 05.10.2021, 23:26 authored by Ronaldo Valdir Briani, Danilo De-Oliveira-SilvaDanilo De-Oliveira-Silva, CS Flóride, FA Aragão, CE De Albuquerque, FH Magalhães, FM De Azevedo
The present study aimed at investigating whether the neuromuscular system behaves differently (in terms of force and muscle activity generation) as a function of the task being performed (i.e. maximal voluntary efforts vs stair negotiation) and the presence of patellofemoral pain (PFP) and possible influences of pain intensity. Thirty-eight women with (n = 19) and without PFP (n = 19) had their knee strength (extension joint torque) measured during maximal voluntary isometric contractions (MVIC) and electromyography (EMG) data recorded during both MVIC and stair ascent tasks, which were performed before and after a loading protocol designed to exacerbate pain symptoms. Women with PFP displayed lower levels of vastus medialis (p = 0.002) and vastus lateralis (p = 0.032) EMG activation during MVIC assessments. Conversely, the PFP group showed higher levels of vastus medialis muscle activity during stair climbing (p = 0.007), which happened exclusively after the loading protocol. Similarly, women with PFP displayed lower knee extensor torque only during the MVIC tests performed after the loading protocol, which was moderately correlated with the increase in self-reported pain (p = 0.041, r = 0.37), whereas the changes in EMG activity during stair ascent were not correlated with changes in pain intensity (p = 0.215, r = 0.12). These results suggest that, in comparison to pain-free controls, women with PFP display lower levels of quadriceps EMG activation during maximal contractions, but higher activation during dynamic tasks (stair ascent). In addition, the moderate association between the decrease in knee extensor torque and increase in self-reported pain indicates that care should be taken by clinicians during quadriceps strength evaluation in women with PFP, as misleading outcomes may emerge if the intensity of knee pain is not considered during screening. Additionally, rehabilitation strategies should focus on both restoring neuromuscular control and increasing muscle strength.
The Sao Paulo Research Foundation is acknowledged for the funding. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Article NumberARTN e0205553
Pagination16p. (p. 1-16)
PublisherPublic Library of Science
Rights StatementThe Author reserves all moral rights over the deposited text and must be credited if any re-use occurs. Documents deposited in OPAL are the Open Access versions of outputs published elsewhere. Changes resulting from the publishing process may therefore not be reflected in this document. The final published version may be obtained via the publisher’s DOI. Please note that additional copyright and access restrictions may apply to the published version.
Science & TechnologyMultidisciplinary SciencesScience & Technology - Other TopicsANTERIOR KNEE PAINISOMETRIC CONTRACTIONSSURFACE ELECTROMYOGRAPHYPHYSICAL-ACTIVITYOUTCOME MEASURESHOFFMANN REFLEXMUSCLE PAINKINEMATICSEMGACTIVATIONKnee JointHumansPatellofemoral Pain SyndromePain MeasurementElectromyographyVolitionIsometric ContractionTorqueFemaleQuadriceps MuscleMuscle StrengthYoung AdultBiomechanical PhenomenaStair ClimbingGeneral Science & Technology