OBJECTIVE The purpose of this article is to show the important radiographic criteria that indicate the two types of femoroacetabular impingement: pincer and cam impingement. In addition, potential pitfalls in pelvic imaging concerning femoroacetabular impingement are shown. CONCLUSION Femoroacetabular impingement is a major cause for early "primary" osteoarthritis of the hip. It can easily be...

BACKGROUND External impingement tests are considered as being particularly reliable for identifying subacromial and coracoid shoulder impingement mechanisms. The purpose of the present study was to evaluate if these tests are likely to provoke an internal shoulder impingement mechanism which, in cases of a pathologic condition, can lead to a positive test result. METHOD In 37 subjects, the me...

The purpose of the study was to determine whether wheelchair-based circuit resistance training (CRT) exercises place the shoulder at risk for mechanical impingement. Using a novel approach, we created a mechanical impingement risk score for each exercise by combining scapular and glenohumeral kinematic and exposure data. In a case series design, 18 individuals (25-76 yr old) with paraplegia and...

Mathematical models and associated numerical techniques have been developed to investigate the complicated transport phenomena in spot hybrid laser-MIG keyhole welding. A continuum formulation is used to handle solid phase, liquid phase, and the mushy zone during the melting and solidification processes. The volume of fluid (VOF) method is employed to handle free surfaces, and the enthalpy meth...

BACKGROUND Femoroacetabular impingement is a frequent cause of hip pain and may lead to secondary osteoarthritis, yet little is known about the molecular events linking mechanical hip impingement and articular cartilage degeneration. The first goal of this study was to quantify the expression of inflammatory cytokine and chemokine, matrix-degrading, and extracellular matrix genes in articular c...

BACKGROUND Archery related injuries, such as shoulder impingement syndrome are caused by repeated motion of the shoulder. The aim of this study was to analyze differences in the shoulder kinematics and the associated muscle activity between archers with shoulder impingement and uninjured archery players. METHODS Thirty male archers, who were divided into an impingement group and an uninjured ...

BACKGROUND Previous studies have indicated that hip and pelvis kinematics may be altered during functional tasks in persons with femoroacetabular impingement. The purpose of this study was to compare hip and pelvis kinematics and kinetics during a deep squat task between persons with cam femoroacetabular impingement and pain-free controls. METHODS Fifteen persons with cam femoroacetabular imp...

BACKGROUND Little is known about the incidence and characteristics of primary, or external, shoulder impingement in an occupationally and physically active population. A longitudinal, prospective epidemiologic database was used to determine the incidence and risk factors for shoulder subacromial impingement in the United States (U.S.) military. Our hypothesis was that shoulder impingement is in...

Methods Fifty-five patients who underwent arthroscopic subacromial decompression were analyzed. Pre-operatively patients completed an assessment form consisting of visual analogue pain score, and shoulder satisfaction. The degree of clinical impingement was also recorded. At arthroscopy impingement was classified according to the Copeland-Levy classification. Post-operatively the shoulder asses...

Impinging jets have received considerable attention during the last decade. The reason is mainly due to their inherent characteristics of high rates of heat transfer besides having simple geometry. Thus most practical applications of jet impingement occur in industries where the heat transfer requirements have exceeded capacity of ordinary heating and cooling techniques. This work presents and ...