A perturbation-based balance training program for older adults: study protocol for a randomised controlled trial

<p>Abstract</p> <p>Background</p> <p>Previous research investigating exercise as a means of falls prevention in older adults has shown mixed results. Lack of specificity of the intervention may be an important factor contributing to negative results. Change-in-support (CIS) balance reactions, which involve very rapid stepping or grasping movements of the limbs, play a critical role in preventing falls; hence, a training program that improves ability to execute effective CIS reactions could potentially have a profound effect in reducing risk of falling. This paper describes: 1) the development of a perturbation-based balance training program that targets specific previously-reported age-related impairments in CIS reactions, and 2) a study protocol to evaluate the efficacy of this new training program.</p> <p>Methods/Design</p> <p>The training program involves use of unpredictable, multi-directional moving-platform perturbations to evoke stepping and grasping reactions. Perturbation magnitude is gradually increased over the course of the 6-week program, and concurrent cognitive and movement tasks are included during later sessions. The program was developed in accordance with well-established principles of motor learning, such as individualisation, specificity, overload, adaptation-progression and variability. Specific goals are to reduce the frequency of multiple-step responses, reduce the frequency of collisions between the stepping foot and stance leg, and increase the speed of grasping reactions. A randomised control trial will be performed to evaluate the efficacy of the training program. A total of 30 community-dwelling older adults (age 64–80) with a recent history of instability or falling will be assigned to either the perturbation-based training or a control group (flexibility/relaxation training), using a stratified randomisation that controls for gender, age and baseline stepping/grasping performance. CIS reactions will be tested immediately before and after the six weeks of training, using platform perturbations as well as a distinctly different method of perturbation (waist pulls) in order to evaluate the generalisability of the training effects.</p> <p>Discussion</p> <p>This study will determine whether perturbation-based balance training can help to reverse specific age-related impairments in balance-recovery reactions. These results will help to guide the development of more effective falls prevention programs, which may ultimately lead to reduced health-care costs and enhanced mobility, independence and quality of life.</p

TREADMILL WALKING IS PROBLEMATIC FOR THE STUDY OF GAIT SMOOTHNESS IN OLDER ADULTS

T.J. Kataras, M.M. Ruwitch, B.S. Row Lazzarini Willamette University, Salem, OR Gait smoothness, related to fall risk in older adults, can be quantified via the harmonic ratio (HR) of trunk accelerations. Relative to the base frequency of two steps within a stride, HR is a ratio of the in-phase (even) vs. out-of-phase (odd) harmonics for the vertical, anterior-posterior (AP) and Medio lateral (ML) acceleration during walking. Larger HR indicates smoother gait. Treadmills are appealing for studies of walking function, given the ability to capture long, straight, uninterrupted walking trials, but it is unknown whether treadmill walking affects HR. Both young and old participants self-select slower preferred walking speeds on the treadmill than for over ground walking. Some older adults cannot reach their usual over ground walking speeds on a treadmill, which may make treadmill walking inappropriate for studying HR with older adults because slower than preferred walking speed reduces HR (Lowry et al., 2012). PURPOSE: The purpose of this study was to examine the effects of speed and treadmill walking on the HR of older adults. Gait symmetry in older adults (n = 40, mean [SD] age: 79 [5.9]) was examined during over ground (OG) and treadmill (TM) walking by calculating the HR over 34 (4.0) steps from linear accelerations measured from a triaxial accelerometer taped to the lumbar spine. TM walking was performed at two speeds: a speed matching the natural OG walk speed (achieved by 30 participants), and a preferred TM speed (PTM) (38 participants). Statistical analysis included only participants who completed each trial (n = 30), and used a one-way Analysis of Variance (ANOVA) with Bonferroni corrected post hoc comparisons. RESULTS: Average OG speed (mean [SD]: 1.34 [0.18] m/s) was faster than PTM (1.17 [0.25] m/s, p \u3c 0.001). There was a trend (ANOVA p = 0.101) toward significance for vertical HR, at 3.71 (0.79) for OG, TM at OG speed was similar at 3.68 (1.08), and PTM reduced vertical HR compared to TM at OG speed (3.36 [1.1], p = 0.039). HR was significantly reduced during PTM compared to TM walking at OG speed for both AP HR (TM at OG speed: 3.81 [1.08], PTM: 3.25 [1.37], p = 0.002) and ML HR (TM at OG speed: 2.79 [0.81], PTM: 2.49 [0.65], p = 0.015). CONCLUSION: The use of TM for HR studies in older adults is problematic, since some will not achieve OG speed during TM walking, and walking at the slower PTM speed reduces gait smoothness in all three planes of motion. Supported by Willamette University Science Collaborative Research Program, Willamette University iHuman Science Gran

3-(2-Anilino-1,3-thiazol-4-yl)-2H-chromen-2-one

The crystal structure of the title compound,$C_{19}H_{13}BrN_{2}O_{2}S$,contains two molecules (A and B) in the asymmetric unit. The planar coumarin systems make dihedral angles of 5.47 (1) and $6.42 (1){^o}$ with the thiazole rings in the two unique molecules.The structure is stabilized by intermolecular N—H...N, N—H...O, C—H...O and C—H... hydrogen bonds andaromatic stacking interactions; intramolecular C—H...Ohydrogen bonds also influence the molecular conformation

Concomitant Polymorphism in 3-Acetylcoumarin: Role of Weak C-H \cdot\cdot\cdot O and C-H \cdot\cdot\cdot \pi Interactions

An analysis of structural features associated with polymorphism in 3-acetylcoumarin has been made in terms of morphology, infrared spectroscopy, crystal structure, powder X-ray diffraction, and differential scanning calorimetric measurements. The appearance of concomitant polymorphs is found to depend on the crystallization temperature in the 1:1 chloroform/hexane solvent system. C-H \cdot\cdot\cdot O and C-H\cdot\cdot\cdot \pi interactions stabilize one form in a head to head configuration, while only C-H\cdot\cdot\cdot O interactions stabilize the other in a head to tail configuration of the molecules in the crystal lattice

Effects of exercise on kidney function among non-diabetic patients with hypertension and renal disease: randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Chronic kidney disease is an important public health threat. Such patients present high morbidity and mortality due to cardiovascular disease, with low quality of life and survival, and also high expenditure resulting from the treatment. Arterial hypertension is both a cause and a complication of kidney disease; also, arterial hypertension is a risk factor for cardiovascular disease among patients with kidney diseases. There is some evidence that exercise interventions may be beneficial to chronic kidney disease patients, but previous studies included only end-stage patients, i.e. those undergoing dialysis. This study aims to evaluate the effect of exercise on kidney function, quality of life and other risk factors for cardiovascular disease among non-diabetic chronic hypertensive kidney disease patients who are not undergoing dialysis.</p> <p>Methods</p> <p>The participants will be located through screening hypertensive patients attended within the public healthcare network in Pelotas, a city in south of Brazil. Eligible individuals will be those with glomerular filtration rate between 15 and 59 ml/min x 1.73 m². The randomization will be done in fixed-size blocks of six individuals such that 75 participants will be allocated to each group. At baseline, information on demographic, socioeconomic, behavioral, anthropometric, blood pressure and quality-of-life variables will be collected, and laboratory tests will be performed. The intervention will consist of three weekly physical exercise sessions lasting 60–75 minutes each, with a total duration of 16 weeks. The outcomes will be the kidney function progression rate, quality of life, blood pressure, lipid profile, hemoglobin level, ultrasensitive C-reactive protein level, and ankle-arm index. The patients in both groups (intervention and control) will be reassessed and compared partway through the study (8^th week), at the end of the intervention (16^th week) and in the 8^th week after the end of the intervention.</p> <p>Discussion</p> <p>There is still a scarcity of data relating to the effect of physical exercise among the most numerous group of individuals with kidney disease, i.e. patients undergoing conservative treatment. In particular, there is a lack of randomized controlled studies. This study will help fill this gap.</p