Purpose: Q-angle measurement procedure have not been well standardised. There is a lack\nof consensus about subject position and knee flexion angle while measuring the Q-angle.\nMorover Q-angle value which obtained in a single position is a static value and gives an\ninformation about the subject’s current position. The aim of this study is to obtain a more\nsignificant parameter which includes different postures (supine, standing, sitting) and\ndifferent knee flexion angles instead of a single Q-angle in a fixed position. At the same time\nthis parameter must be functional and dynamic,not a static value like Q-angle. We named this\nparameter as ΔQ.\nMethods: Our study was applied on case and control groups. All subjects in both groups\nwere male. Case group was consisted of 14 subjects who had patellofemoral pain. Control\ngroup was consisted of 14 subjects who had normal knees and normal lower extremities with\nno reported knee problems. We obtained 3 different Q-angle values and 3 different ΔQ values\nfor each subject in both groups. Pearson correlation analysis was used for investigation of\ncontinuous variables in normal distribution, Spearman correlation analysis was used in\nabnormal distribution. t test was used in the comparison of values. Logistic regression\nanalysis(forward conditional mod) was used for detecting of determinants of pain.\nResults: ΔQ1s of both groups were found as the only statistical significant predictive value\nfor patellofemoral pain.\nConclusion: There is not an agreement about a standardised q-angle measurement\nprocedure in the literature. Moreover,present procedures provide information about a single\nand fixed position. In this situation Q-angles which obtained in these fixed positions are static\nvalues. We think that we can overcome these problems with this new value. ΔQ contains\nmultiple q-angles and gives information about all. Also it is a dynamic value for being\noriented to position change. ΔQ is an useful indicator for evaluating patellofemoral pain.