A 5-year profile of the incidence of total joint replacement in South Africa (1985 - 1989)

This survey was conducted to determine the number of total joint replacements (TJRs) carried out annually in South Africa from 1985 to 1989 and the nwnber of surgeons performing these procedures. During this period there was a 28% increase in the number of TJRs performed annually with an average increase of 20% in total hip replacements and 40% in total knee replacements. The number of surgeons involved in joint replacement during the survey period decreased by 7% in state-subsidised institutions but increased by 57% in the private sector. This is reflected in the number of TJRs performed each year, which has remained static in the state institutions but exhibits a threefold increase in the private sector. This probably reflects a shift in emphasis in state health care policy

Changing Behaviour towards Aerobic and Strength Exercise (BASE): Design of a randomised, phase I study determining the safety, feasibility and consumer-evaluation of a remotely-delivered exercise programme in persons with multiple sclerosis

Background Multiple sclerosis is a chronic progressive neurological disease. Evidence attests to the benefits of exercise, guidelines for exercise in multiple sclerosis are available. Remote-delivery of exercise adherence programmes based on the exercise guidelines require urgent testing. Aims The design, and outcomes of Behaviour towards Aerobic and Strength Exercise in MS (BASE-MS), a remotely-delivered exercise training study based principles of behaviour change, will further evaluate the remote-delivery of the current exercise guidelines. Methods BASE is a 4-month clinically relevant randomised controlled trial to explore the delivery of a remotely supervised, guidelines-based exercise programme for persons with multiple sclerosis, underpinned by principles of health behaviour change. Initially, 72 persons with mild to moderate multiple sclerosis will be randomised in a 1:1:1 allocation to receive the BASE programme, or act as controls continuing usual care. On programme completion, exercise participants will be further randomised to an optimised adherence treatment or usual adherence. Our online survey assesses the primary outcome of exercise participation, and secondary outcomes of symptoms, and correlates of behaviour change at baseline, month four, month five and month eleven. Online surveys will capture coach and participant feedback to identify the contexts, mechanisms and outcomes of BASE implementation. Conclusions The research and clinical landscape for MS management must remain in-step with public health and health communication. BASE tests the remote-delivery of the current exercise guidelines for exercise in persons with MS. Safety, feasibility and evaluative outcomes will provide rich data for future remote-delivery of exercise in neurological conditions

Mobile EEG reveals functionally dissociable dynamic processes supporting real-world ambulatory obstacle avoidance : evidence for early proactive control

This work is supported by a scholarship from the University of Stirling and a reseach grant from SINAPSE (Scottish Imaging Network: A Platform for Scientific excellence). GL is supported by the Wellcome Trust [209209/Z/17/Z].The ability to safely negotiate the world on foot takes humans years to develop, reflecting the huge cognitive demands associated with real‐time planning and control of walking. Despite the importance of walking, methodological limitations mean that surprisingly little is known about the neural and cognitive processes that support ambulatory motor control. Here, we report mobile EEG data recorded from thirty‐two healthy young adults during real‐world ambulatory obstacle avoidance. Participants walked along a path while stepping over expected and unexpected obstacles projected on the floor, allowing us to capture the dynamic oscillatory response to changes in environmental demands. Compared to obstacle‐free walking, time‐frequency analysis of the EEG data revealed clear frontal theta and centro‐parietal beta power neural markers of proactive and reactive forms of movement control (occurring before and after crossing an obstacle). Critically, the temporal profile of changes in frontal theta allowed us to arbitrate between early selection and late adaptation mechanisms of proactive control. Our data show that motor plans are updated as soon as an upcoming obstacle appears, rather than when the obstacle is reached. In addition, regardless of whether motor plans required updating, a clear beta rebound was present after obstacles were crossed, reflecting the resetting of the motor system. Overall, mobile EEG recorded during real‐world walking provides novel insight into the cognitive and neural basis of dynamic motor control in humans, suggesting new routes to the monitoring and rehabilitation of motor disorders such as dyspraxia and Parkinson’s disease.Publisher PDFPeer reviewe

Implementing changing behaviour towards aerobic and strength exercise: results of a randomised, phase I study determining the safety, feasibility, and consumer-evaluation of an online exercise program in persons with multiple sclerosis

Background: Many people with MS do not meet the recommended exercise regime to elicit health benefits. This study aimed to determine the feasibility, safety, acceptability, and appropriateness of an exercise intervention delivered online to persons with MS that meets current exercise recommendations and behaviour change principles. Methods: Seventy-two participants (age: 43.3 ± 13.3 years) with mild to moderate MS were stratified according to previous exercise behaviour and block-randomised into one of three groups: Control (CON; n = 24), General Exercise (GE; n = 24) who at screening did not meet current exercise recommendations, and Advanced Exercise, (AE; n = 24) who at screening met the current exercise recommendations. GE and AE groups received a four-month online-supervised, behaviour change theory-based exercise program and were assessed at baseline, four-months, five-months, and eleven-months for physical activity participation. The feasibility of process, resources, management, and scientific outcomes was assessed. Results: Of 198 potential participants, 143 met the eligibility criteria (72 %), and 72 were randomised. Fifty-three participants completed the intervention (74 % immediate retention), and 44 were retained at the six-month follow-up (61 %). Personnel time was 369 h, and total per-participant cost was Au$1036.20. Adherence rate to ≥70 % of exercise sessions was 73 % (GE) and 38 % (AE). The GE group observed a small magnitude of improvement in physical activity (d = −0.23). Conclusions: An online exercise program embedded with behaviour interventions for either GE or AE appears feasible, acceptable, appropriate and safe and may show long-term efficacy in increased exercise behaviours for persons with mild to moderate MS. Trial registration: ANZCRT number ACTRN12619000228189p.</p

A Comparative Study of Some Pseudorandom Number Generators

We present results of an extensive test program of a group of pseudorandom number generators which are commonly used in the applications of physics, in particular in Monte Carlo simulations. The generators include public domain programs, manufacturer installed routines and a random number sequence produced from physical noise. We start by traditional statistical tests, followed by detailed bit level and visual tests. The computational speed of various algorithms is also scrutinized. Our results allow direct comparisons between the properties of different generators, as well as an assessment of the efficiency of the various test methods. This information provides the best available criterion to choose the best possible generator for a given problem. However, in light of recent problems reported with some of these generators, we also discuss the importance of developing more refined physical tests to find possible correlations not revealed by the present test methods.Comment: University of Helsinki preprint HU-TFT-93-22 (minor changes in Tables 2 and 7, and in the text, correspondingly

The development of path integration: combining estimations of distance and heading

Efficient daily navigation is underpinned by path integration, the mechanism by which we use self-movement information to update our position in space. This process is well-understood in adulthood, but there has been relatively little study of path integration in childhood, leading to an underrepresentation in accounts of navigational development. Previous research has shown that calculation of distance and heading both tend to be less accurate in children as they are in adults, although there have been no studies of the combined calculation of distance and heading that typifies naturalistic path integration. In the present study 5-year-olds and 7-year-olds took part in a triangle-completion task, where they were required to return to the startpoint of a multi-element path using only idiothetic information. Performance was compared to a sample of adult participants, who were found to be more accurate than children on measures of landing error, heading error, and distance error. 7-year-olds were significantly more accurate than 5-year-olds on measures of landing error and heading error, although the difference between groups was much smaller for distance error. All measures were reliably correlated with age, demonstrating a clear development of path integration abilities within the age range tested. Taken together, these data make a strong case for the inclusion of path integration within developmental models of spatial navigational processing

Total hip arthroplasty: what information do we offer patients on websites of hospitals?

Contains fulltext : 97468.pdf (publisher's version ) (Open Access)BACKGROUND: Physicians face a new challenge; the self-educated patient. The internet is an important source that patients use to become self-educated. However, the individual choice for best treatment is difficult. The aim of this study was to investigate what kind of information is offered to total hip arthroplasty patients by internet and what information is appreciated by them. METHODS: Websites of orthopedic departments of all hospitals in the Netherlands were evaluated. In addition, a cohort of 102 patients, diagnosed with arthritic joint disorders, filled in an online survey and gave their opinion concerning the importance of this information. RESULTS: Eighty different orthopedic websites of hospitals were identified. Websites presented information regarding the orthopedic staff surgeon (76%) and the postoperative rehabilitation process (66%). They also offered referral to other orthopedic websites (61%), the opportunity to make an outpatient appointment (21%), and the opportunity to submit an online question (15%). Patients rated the presence of information regarding prosthesis survival as very important (>70%). However, the information on the type of prosthesis used by the hospital, and survival data of the prosthesis, were only present in ~9% and 5% respectively, of the websites. CONCLUSIONS: The content of health information on websites of hospitals is highly variable for total hip arthroplasty. Information regarding the hip implant and prosthesis survival is highly appreciated by patients, however, mostly absent on orthopedic websites in the Netherlands. The internet provides an enormous potential for orthopedic surgeons to inform the self-educated patient