Recent epidemiological studies report that obesity is positively related to fracture incidence. In the present experiment, a model of postural control was used to examine the impact of an abnormal distribution of body fat in the abdominal area upon postural stability. Obese and lightweight humanoids were destabilized by imposing a small initial angular speed from a neutral standing position. To avoid a loss of stability yielding a stepping reaction or a fall, an ankle torque is necessary to counteract the perturbation. Three torque parameters-ankle torque onset, time to peak torque, and muscular ankle torque-were entered in a program to simulate the intrinsic variability of the human postural control system. A loss of stability was detected when the center of pressure exceeded stability margins. The most striking observation is the nonlinear increase of torque needed to stabilize the humanoid when the motor response was chararterized by delayed temporal parameters. The effect was more pronounced when an anterior position of the center of mass was included in the simulations. This suggests that, when submitted to daily postural stresses and perturbations, obese persons (particularly those with an abnormal distribution of body fat in the abdominal area) may be at higher risk of falling than lightweight individuals.

"Change-in-support" (CIS) balance-recovery reactions that involve rapid stepping or reaching movements play a critical role in preventing falls; however, age-related deficits in the neuro-musculoskeletal systems may impede ability to execute these reactions effectively. This review describes four new interventions aimed at reducing fall risk in older adults by promoting more effective CIS reactions: (1) balance training, (2) balance-enhancing footwear, (3) safer mobility aids, and (4) handrail cueing systems. The training program uses unpredictable support-surface perturbations to counter specific CIS control problems associated with aging and fall risk. Pilot testing has demonstrated that the program is well-tolerated by balance-impaired older adults, and a randomized controlled trial is now in progress. The balance-enhancing footwear insole improves control of stepping reactions by compensating for age-related loss of plantar cutaneous sensation. In a clinical trial, subjects wore the insole for 12 weeks with no serious problems and no habituation of the balance-enhancing benefits. The mobility-aid intervention involves changes to the design of pickup walkers so as to reduce impediments to lateral stepping. Finally, work is underway to investigate the effectiveness of handrail cueing in attracting attention to the rail and ensuring that the brain registers its location, thereby facilitating more rapid and accurate grasping.

Recent studies suggest that walking on a treadmill improves gait, mobility, and quality of life of patients with Parkinson's disease (PD). Still, there is a need for larger-scale randomized controlled studies that demonstrate the advantages of treadmill training (TT) with control groups that receive similar amounts of attention. Moreover, to date, no study has combined speed and incline as parameters of progression. The aim of the study was to evaluate the effects of 24 wk of TT, with and without the use of incline, on gait, mobility and quality of life in patients with PD. The sample comprised 34 patients with PD, at the Hoehn and Yahr stage 1.5 or 2. Participants were randomized to speed TT, mixed TT, and control groups. The intervention consisted of 72 one-hour exercise sessions for 24 wk. The main outcome measures are the Movement Disorder Society-Unified Parkinson's Disease Rating Scale, the 39-item Parkinson's Disease Questionnaire, spatiotemporal parameters of gait and 6-min walking distance. The measures were taken at baseline, mid-term and after 6 months. Both TT groups improved in terms of speed, cadence, and stride length during self-selected walking conditions at the study end point. Both groups also showed improvements in distance traveled. Only the Mixed TT group improved their quality of life. The Control group showed no progress. Participants in this study showed significant improvements in walking speed and walking endurance after 6 months of TT. Improvements were observed after 3 months of intensive TT and persisted at 6 months. It appears that individuals with poorer baseline performance may benefit most from TT.

Purpose: The impacts of emergency work on firefighters have been well documented and summarised, but this is not the case for paramedics. This paper explores the literature regarding the impact of work stress on paramedics. Objective: To identify the literature available on the effect of paramedics’ jobs on their health status. Methods: Electronic database used: MEDLINE (Ovid, PubMed, National Library of Medicine) between 2000 and 2011. Key words used for the computer searches were: paramedics, emergency responders, emergency workers, shift workers, post-traumatic symptoms, obesity, stress, heart rate variability, physiological response, blood pressure, cardiovascular and cortisol. Exclusion criteria were: studies in which participants were not paramedics, participants without occupational exposure, physical fitness assessment in paramedics and epidemiological reports regarding death at work. Results: The electronic databases cited 42 articles, of which we excluded 17; thus, 25 articles are included in this review. It seems clear that paramedics accumulate a set of risk factors, including acute and chronic stress, which may lead to development of cardiovascular diseases. Post-traumatic disorders, sleeping disorders and obesity are prevalent among emergency workers. Moreover, their employers use no inquiry or control methods to monitor their health status and cardiorespiratory fitness. Conclusions: More studies are needed to characterise paramedics’ behaviour at work. These studies could allow the development of targeted strategies to prevent health problems reported in paramedics.