Validity and Reliability of Autocad Software Assessment of JPS in PFPS

The participants will be prepared for image-capture data collection by putting four squared markers on leg and thigh.Each subject will extend his/her leg and make two angles from the resting position (90º) to the full extension, photos will be taken. The tested leg passively moved by the researcher through 20° to 60° of knee extension, the participant will be instructed to actively move that leg to the target angle and hold it in this position another photograph will be taken. The angles will be measured using the AutoCAD software. Knee JPS measurements will also be collected using an IKD by same steps