Patellar kinematics, part I: the influence of vastus muscle activity in subjects with and without patellofemoral pain.
BACKGROUND AND PURPOSE: Reduced motor unit activity of the vastus medialis muscle relative to the vastus lateralis muscle has been implicated as a cause of lateral patellar subluxation. The purpose of this study was to assess the influence of vastus muscle motor unit activity on patellar kinematics....
| Publicado en: | Physical Therapy Vol. 80; no. 10; pp. 956 - 965 |
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| Autor principal: | |
| Formato: | research tables/charts Journal Article |
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Oxford University Press / USA
Oct2000
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=106991323&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 106991323 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 00319023 PTH jtl: Physical Therapy issn: 00319023 maglogo: N pubinfo: dt: Oct2000 vid: 80 iid: 10 pid: 10398 pub: Oxford University Press / USA artinfo: ui: 106991323 106991323 2001003689 10.1093/ptj/80.10.956 NLM11002431 106991323 ppf: 956 ppct: 9 formats: fmt: – @attributes: type: T – @attributes: type: P tig: atl: Patellar kinematics, part I: the influence of vastus muscle activity in subjects with and without patellofemoral pain. aug: au: Powers CM affil: Assistant Professor, Dept of Biokinesiology and Physical Therapy, University of Southern California, 1540 E Alcazar St, CHP-155, Los Angeles, CA 90033; powers@hsc.usc.edu sug: subj: Patellofemoral Pain Syndrome Etiology Knee Joint Physiology Kinematics Patella Physiology Knee Joint Pathology Quadriceps Muscles Physiology Extension Electromyography Magnetic Resonance Imaging Comparative Studies Data Analysis Software One-Way Analysis of Variance Intraclass Correlation Coefficient Repeated Measures Regression Correlation Coefficient Adult Female Funding Source Human Adult: 19-44 years Female ab: BACKGROUND AND PURPOSE: Reduced motor unit activity of the vastus medialis muscle relative to the vastus lateralis muscle has been implicated as a cause of lateral patellar subluxation. The purpose of this study was to assess the influence of vastus muscle motor unit activity on patellar kinematics. SUBJECTS: Twenty-three women (mean age=26.8 years, SD=8.5, range=14-46) with a diagnosis of patellofemoral pain and 12 women (mean age=29.1 years, SD=5.0, range=24-38) without patellofemoral pain participated. Only female subjects were studied because of potential biomechanical differences between sexes. METHODS: Patellar kinematics (kinematic magnetic resonance imaging) and vastus muscle electromyographic (EMG) activity using indwelling electrodes were measured during resisted knee extension. Measurements of medial and lateral patellar displacement and tilt obtained from magnetic resonance images were correlated with normalized vastus lateralis:vastus medialis oblique muscle and vastus lateralis:vastus medialis longus muscle EMG ratios at 45, 36, 27, 18, 9, and 0 degrees of knee flexion using a stepwise regression procedure. RESULTS: The vastus lateralis:vastus medialis longus muscle EMG ratio contributed to the prediction of lateral patellar glide at 27 degrees of knee flexion (r=-.48), with increased vastus medialis longus muscle activity being associated with greater lateral patellar displacement. A similar inverse relationship was evident with lateral patellar tilt at 36, 27, 18, and 9 degrees of knee flexion. CONCLUSION AND DISCUSSION: These results suggest that increased motor unit activity of the vastus medialis muscle appears to be associated with abnormal patellar kinematics in women, but it is not necessarily a cause of abnormal patellar kinematics. pubtype: Academic Journal doctype: research tables/charts Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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