BACKGROUND AND PURPOSE Reduced motor unit activity of the vastus medialis muscle relative to the vastus lateralis muscle has been implicated as a cause of lateral patellar subluxation. The purpose of this study was to assess the influence of vastus muscle motor unit activity on patellar kinematics. SUBJECTS Twenty-three women (mean age=26.8 years, SD=8.5, range=14-46) with a diagnosis of pate...

STUDY DESIGN Single-group, repeated-measures design. OBJECTIVE To compare patellofemoral joint kinematics during weight-bearing and non-weight-bearing knee extension in persons with lateral subluxation of the patella. BACKGROUND The only previous study to quantify differences in patellofemoral joint kinematics during weight-bearing and non-weight-bearing tasks was limited in that static loa...

Background: There are a number of different factors that are thought to play a role in patellar instability, including injuries to the medial patellofemoral ligament (MPFL), trochlear dysplasia, patella alta, and an increased tibial tuberosity-trochlear groove (TT-TG) distance. Objective: To use MRI to assess injury patterns to the MPFL, trochlear dysplasia, patellar height, and TT-TG distance ...

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OBJECTIVE To make a comparative analysis on three femoropatellar radiographic parameters, between knees with chronic failure of the anterior cruciate ligament (ACL) and normal knees. METHODS Thirty volunteer patients with a diagnosis of unilateral isolated chronic ACL injury for more than one year and a normal contralateral knee were selected. Digital radiographs were produced for all the pat...

OBJECTIVE: To evaluate the usefulness of combining static and kinematic magnetic resonance imaging in the evaluation of the femoropatellar joint. MATERIALS AND METHODS: Twenty healthy volunteers (40 knees) and 23 patients (43 knees) were submitted to both static and kinematic magnetic resonance imaging on a 1.5 tesla whole-body magnetic resonance scanner. The knees were positioned at 30o flexio...

Abnormal patellofemoral joint motion is a possible cause of patellofemoral pain, and patellar braces are thought to alleviate pain by restoring normal joint kinematics. We evaluated whether females with patellofemoral pain exhibit abnormal patellofemoral joint kinematics during dynamic, weight-bearing knee extension and assessed the effects of knee braces on patellofemoral motion. Real-time mag...

Patellofemoral cartilage degeneration is a potential complication of anterior cruciate ligament reconstruction (ACLR) surgery. Hypomobility of the patella in the coronal plane is often observed after ACLR. Few studies, however, have examined the relationship between cartilage degeneration in the patellofemoral joint and mobility after ACLR. The present study investigated 1) the coronal mobility...

medialis obliquus, is the main passive stabilizer of the patellofemoral joint. Recently, it has been shown that the medial patellofemoral complex is the main pathoanatomy after patellar dislocation [1-3] . In addition, biomechanical studies have demonstrated that the MPFL is the main restraint against lateral patellar displacement and that repair or reconstruction of the MPFL restores normal pa...