Transcript Meeting0611
The Influence of Vastus Muscle on Patella Alignment and Balance in Subjects With Patellofemoral Pain Syndrome Reporter: Chao-jung Hsieh Supervisor: Sai-wei Yang Date: 2007/6/11 1 Introduction • Patellofemoral pain syndrome (PFPS) Peripatellar or retropatellar pain results from physical and biomechanical changes in the patellofemoral joint Subjects with PFPS have more symptoms and pain during the last 30° of maximal sitting knee extension Thomee et al 1995 2 Pathomechanics Bony Alignment Soft Tissue Femoral Patella Increased anteversion malalignment Q angle Insufficient flexibility Strength deficit Abnormal biomechanics Abnormal patella tracking Excessive pressure on patellofemoral joint Patellofemoral pain syndrome 3 Literature review • The EMG activity of the vastus medialis oblique is pronounced at the end-range of extension which emphasizes the function of the structure in providing medial patella stability Fulkerson 1990 • Effective control of balance also relies on a timely response of strong muscles 4 Purpose • To investigate the influence of vastus muscle and patella alignment in subjects with PFPS • To evaluate the relationship of impairment of balance and muscle strength of the knee Hypothesis • Vastus medialis oblique and vastus lateralis muscle imbalance would be associated with Lateral patella tracking Poor balance 5 Methods • Subjects: 30 subjects diagnosed with PFPS • Preliminary examination: Postural alignment Leg length Femoral anteversion Tibial torsion Q angle Muscle flexibility test Estimating the pain intensity: visual-analog scale 6 Methods • Condition: during muscle isokinetic contraction • Variables: Patella alignment Lateral patella angle Lateral patella displacement Measured at 30°.45° and 60° of knee flexion Vastus medialis oblique and vastus lateralis Electrical activity (EA)-muscle activity 7 Methods Equipments Electromyography Isokinetic dynamometer Stewart platform 8 References • Christopher MP(2000) Patellar kinematics, part I: The influence of vastus muscle activity in subjects with and without patellofemoral pain. Physical therapy. 10:956-964 • Davies AP, Bayer J(2004) The optimum knee flexion angle for skyline radiography is thirty degrees. Clinical orthopaedics and related research. 423:166-171 • Goran MH, Alwin L, Matthias J(2000) Methodologies for evaluating electromyographic field data in ergonomics. Journal of electromyography and kinesiology. 10:301-312 9 Thanks for your listening 10