TY - JOUR T1 - The test-retest reliability of the onset of core and vasti electromyographic activity while ascending and descending stairs in healthy controls and patellofemoral pain patients TT - JF - MJIRI JO - MJIRI VL - 24 IS - 4 UR - http://mjiri.iums.ac.ir/article-1-221-en.html Y1 - 2011 SP - 221 EP - 231 KW - Reliability KW - patellofemoral pain KW - core KW - EMG. N2 - AbstractBackgroundentity. It is hypothesized to result from abnormal patellar tracking caused by altered motorcontrol. Deficit in neuromotor control of the core may be a remote contributing factor to thedevelopment of PFP. Application of reliable EMG measures would be helpful to handle thistheory. Therefore, the purpose of this study was to determine the test-retest reliability of thecore and vasti EMG onsets, while ascending/descending stairs.: Patellofemoral pain (PFP) is a common affliction and complex clinicalMethodsand Core EMG onsets during stair stepping were assessed two times a day. Intraclass correlationcoefficients (ICCs) and standard errors of measurement (SEMs) were calculated.: Ten males with PFP and ten healthy controls participated in this study. VastiResultsonsets of control cases (ICC 3,1 ≥ 0.70) except Quadratus Lumborum (QL) which showeda moderate reliability (ICC for ascending=0.59 and for descending = 0.61). In controls,Vasti in both tasks showed the highest absolute reliability. During ascending, highreliability (ICC ≥ 0.70) in PFP group was demonstrated for all EMG onsets except Gluteusmaximus (GMAX) and QL which showed a moderate reliability (ICC = 0.69 and 0.63 respectively).In this group while descending stairs, all EMG onsets showed high relativereliability (ICC ≥ 0.70). Moderate to high absolute reliability was obtained for onset timeswhile ascending/descending stairs in PFP group.: During both ascending/descending, high reliability was found for all EMGConclusionreliability.: Most EMG onsets during stair ascending/descending had moderate to high M3 ER -