Particulate air pollution, systemic oxidative stress, inflammation, and atherosclerosis

Air pollution has been associated with significant adverse health effects leading to increased overall morbidity and mortality of worldwide significance. Epidemiological studies have shown that the largest portion of air pollution-related mortality is due to cardiovascular diseases, predominantly those of ischemic nature. Human studies suggest an association with atherosclerosis and increasing experimental animal data support that this association is likely to be causal. While both gasses and particles have been linked to detrimental health effects, more evidence implicates the particulate matter (PM) components as major responsible for a large portion of the proatherogenic effects. Multiple experimental approaches have revealed the ability of PM components to trigger and/or enhance free radical reactions in cells and tissues, both ex vivo as well as in vivo. It appears that exposure to PM leads to the development of systemic prooxidant and proinflammatory effects that may be of great importance in the development of atherosclerotic lesions. This article reviews the epidemiological studies, experimental animal, and cellular data that support the association of air pollutants, especially the particulate components, with systemic oxidative stress, inflammation, and atherosclerosis. It also reviews the use of transcriptomic studies to elucidate molecular pathways of importance in those systemic effects

Biomechanical differences between experienced and inexperienced wheelchair users during sport

Background: During functional wheelchair movement there are several types of stroke pattern that a manual wheelchair user (MWCU) can utilize in order to propel. Objectives: To examine the biomechanical differences between disabled (WCU) and able-bodied (NWCU) children whilst taking part in functional activities at the Cheetahs Wheelchair Sports Club. Study Design: A multiple measures cohort study. Methods: Eleven participants were divided into two groups; WCU (n = 7) and NWCU (n = 4). All subjects were asked to perform three functional tasks; 30-second agility test, 1-minute distance test and a 10-metre sprint test. Upper body kinematics were recoded using a XSens MVN BIOMECH motion capture suit. Results: NWCU outperformed the WCU in all of the tasks, however, no significant differences between the group’s results were found. Nevertheless, significant differences were found in the maximum shoulder flexion angle for both right and left with NWCU utilizing more flexion and near significant differences in the NWCU overall shoulder range for right and left. Conclusions: In order to increase function in young MWCU then more specific-based sessions should be implemented targeting the exploitation of large shoulder ranges during propulsion, consequently resulting in more efficient movement. Clinical relevance Employing a propulsion technique which uses larger ranges of shoulder motion and decreased pushrim frequency results in an optimal cost-effect balance without predisposing MWCU to overuse injuries

Clinical applications of musculoskeletal modelling for the shoulder and upper limb

Musculoskeletal models have been developed to estimate internal loading on the human skeleton, which cannot directly be measured in vivo, from external measurements like kinematics and external forces. Such models of the shoulder and upper extremity have been used for a variety of purposes, ranging from understanding basic shoulder biomechanics to assisting in preoperative planning. In this review, we provide an overview of the most commonly used large-scale shoulder and upper extremity models and categorise the applications of these models according to the type of questions their users aimed to answer. We found that the most explored feature of a model is the possibility to predict the effect of a structural adaptation on functional outcome, for instance, to simulate a tendon transfer preoperatively. Recent studies have focused on minimising the mismatch in morphology between the model, often derived from cadaver studies, and the subject that is analysed. However, only a subset of the parameters that describe the model's geometry and, perhaps most importantly, the musculotendon properties can be obtained in vivo. Because most parameters are somehow interrelated, the others should be scaled to prevent inconsistencies in the model's structure, but it is not known exactly how. Although considerable effort is put into adding complexity to models, for example, by making them subject-specific, we have found little evidence of their superiority over current models. The current trend in development towards individualised, more complex models needs to be justified by demonstrating their ability to answer questions that cannot already be answered by existing models.</p