Patellar tendon moment arm length (PTma) changes at different knee flexion angles have not been determined in invivo studies. We aimed to determine PTma in four different knee angles using Magnetic Resonance Imaging (MRI) topredict in vivo changes in the moment arm length from different knee angles during running.PTma was measured as the perpendicular distance from muscle–tend...

 Background: A potential specific problem of patellar tendon graft in ACL reconstruction is the possibility of graft-tunnel mismatch which could be more problematic with anatomic ACL reconstruction where the femoral tunnel is placed low on the lateral wall of the lateral femoral condyle. The occasional occurrence of this mismatch raises the question that whether a correlation exists between pat...

background: a potential specific problem of patellar tendon graft in acl reconstruction is the possibility of graft-tunnel mismatch which could be more problematic with anatomic acl reconstruction where the femoral tunnel is placed low on the lateral wall of the lateral femoral condyle. the occasional occurrence of this mismatch raises the question that whether a correlation exists between pati...

We examined the hypothesis that structural features of the iliotibialis lateralis pars postacetabularis (ILPO) in guinea fowl allow this large muscle to maintain equivalent function along its anterior-posterior axis. The ILPO, the largest muscle in the hindlimb of the guinea fowl, is a hip and knee extensor. The fascicles of the ILPO originate across a broad region of the ilium and ischium post...

The purpose of this study was to compare the knee extensor mechanics in persons with and without patella alta. Thirteen subjects with patella alta and 14 subjects with normal patellar position participated in the study. Sagittal and axial MR images of the knee were acquired at 0 degrees , 20 degrees , 40 degrees , and 60 degrees of knee flexion. Measurements of actual moment arm, patellar ligam...

The moment arm (MA) of the knee extensor mechanism has been reported by a number of researchers, although it has been defined and measured differently in these studies. The aims of this study were: (1) to quantify the MA of the knee-extensor mechanism, which is represented by the MA of the patellar tendon at the knee; and (2) to show that the MA of the patellar tendon is related to the size of ...

PURPOSE Risk factors associated with a clinical presentation of patellar tendinopathy are patellar tendon ultrasonographic abnormality (PTA) and excessive loading. It remains unknown whether characteristics of an athlete's landing technique contribute to this excessive patellar tendon loading. This study investigated whether asymptomatic athletes with and without PTA had different landing strat...

Patella alta is common in cerebral palsy, especially in patients with crouch gait. Correction of patella alta has been advocated in the treatment of crouch, however the appropriate degree of correction and the implications for knee extensor function remain unclear. Therefore, the goal of this study was to assess the impact of patellar position on quadriceps and patellar tendon forces during nor...

Accurate assessment of muscle-tendon forces in vivo requires knowledge of the muscle-tendon moment arm. Dual-energy X-ray absorptiometry (DXA) can produce 2D images suitable for visualising both tendon and bone, thereby potentially allowing the moment arm to be measured but there is currently no validated DXA method for this purpose. The aims of this study were (i) to compare in vivo measuremen...

INTRODUCTION: Patellofemoral pain (PFP) is closely related to static patellar malalignment and patellar maltracking. The etiology of patellar maltracking is multifactorial; relating to femoral shape, passive soft-tissue restraints; and/or an imbalance of forces on the patella. A number of structures, both passive and active, contribute to the force balance on the patella. Previous studies have ...