Purpose: A proper warm-up method can be used as a strategy to improve performance of athletes in various sport fields. The aim of present study was to compare the effect of two traditional and post-activation potentiation warm-up methods on electromyographic variables of lower extremity muscles during squat jump. Methods: Fourteen trained male athletes were randomly performed three different p...

PURPOSE It is not clear how the knee extension torque is distributed quantitatively among the lateral and medial vasti in patellofemoral pain (PFP) patients with patellar malalignment, which was investigated in vivo and noninvasively in ten PFP patients and eleven controls. We hypothesized that the vastus medialis oblique (VMO) and vastus medialis longus (VML) of PFP patients contribute less to...

Patellofemoral pain syndrome (PFPS) is one of the most common knee disorders, with pain located primarily in the lateral aspect of the patellofemoral joint. Force imbalance in the knee extensor muscles has been associated with changes in patellofemoral tracking and is suspected to cause PFPS [1]. Specifically, weakness of the vastus medialis (VM) relative to the vastus lateralis (VL) is the usu...

This study aimed to determine and analyze the neuromuscular fatigue onset by median frequency (MDF) and the root mean square (RMS) behavior of an electromyographic signal (EMG). Eighteen healthy men with no prior knee problems initially performed three maximum voluntary isometric contractions (MVIC). After two days of MVIC test, participants performed a fatiguing protocol in which they performe...

BACKGROUND Patellar tendinopathy identified by imaging modalities has been reported in asymptomatic athletes and associated with tendon-related symptoms. However there is little data in community-based populations. The aim of this cohort study was to examine the prevalence of magnetic resonance imaging (MRI) defined patellar tendinopathy, the factors associated with this condition, and whether ...

Background: The determinant role of different movements to strengthen the quadriceps on rate of knee joint co-contraction, hamstring to quadriceps muscle activity ratio and vastus medialis to vastus lateralis muscle activity ratio provides useful information for therapists, coaches and athletes about the role of each movement in the rehabilitation of patients with anterior cruc...

Patellofemoral pain is a common knee disorder with a multi-factorial etiology related to abnormal patellar tracking. Our hypothesis was that the pattern of three-dimensional rotation and translation of the patella induced by selective activation of individual quadriceps components would differ between subjects with patellofemoral pain and healthy subjects. Nine female subjects with patellofemor...