Patellofemoral stress in runners

Abstract

The aim of this study is to quantify the interrelationship among structural factors, biomechanical factors, and elevated patellofemoral joint stress in recreational runners with patellofemoral pain (PFP). Specific objectives: Determine the influence of movements in frontal and transverse plane of the femur and tibia in the stress of the patellofemoral joint; determine whether recreational runners with patellofemoral pain displays high stress in cartilage during the running; determine structural predictors and/or biomechanical of patellofemoral pain and stress in cartilage in recreational runners. Method: Twenty four recreational runners will be evaluated aged between 18 and 39 years of both sexes. Which will be divided into two groups: group 1) with PFP (n = 12) and group 2) without PFP (n = 12). Evaluations will be performed in Musculoskeletal Biomechanics Research Laboratory of Division of Biokinesiology and Physical Therapy. Three-dimensional kinematic images will be collected on the front and transverse plane of the femur and tibia using 11 cameras (motion capture system) (Qualisys AB, Gotenborg, Sweden) at a sampling rate of 250 Hz, to determine the influence of stress these volunteers. Before the tests the reflective markers will be placed on the bone 21 points (14-reflective mm diameter): end of second toes, first and fifth metatarsal heads, medial and lateral malleoli, medial and lateral epicondyles of femurs, greater trochanters, iliac crests, L5-S1 junction, and acromioclavicular joints. The ground reaction forces will be obtained using a force plate (1500Hz) (Advanced Mechanical Technology, Inc., Watertown, MA). Signs of electromyography (EMG) will be collected of the muscles of the limbs below with EMG equipment system at a sampling rate of 1500 Hz (DTS Telemyo; Noraxon USA Inc, Scottsdale, AZ). The electromyographic signals are collected from the knee flexor muscles (medial and lateral hamstrings and gastrocnemius) and the data will be used to explain muscle co-contraction in biomechanical model, already studied in the laboratory. Analysis: Statistical analysis will be performed each variables, first comparing subjects with and without patellofemoral pain and then analyzing the interrelation between structural factors, biomechanical, and PFJ stress in recreational runners. Statistical analysis will be used SPSS 12.0j software (SPSS Inc., Chicago, IL). Statistical tests will be defined after the data collection. Will be adopted the significance level of p <0.05. (AU)