Efficacy of handrails in preventing stairway falls: a new experimental approach

In previous studies of stairway handrails, data were derived from static experiments which characterized the influence of the handrail design on ability to generate stabilizing force. This paper describes a novel and safe experimental approach developed to study the biomechanical efficacy of handrail use under dynamic conditions, wherein support-surface motion is used to perturb the balance of the subject who stands on a small (three step), heavily padded mock staircase. A primary objective of this initial study was to determine the influence of factors such as perturbation magnitude, stance leg (left or right), proximity to the handrail, initial hand position (on or off the rail), and ability to complete a step while grabbing the rail. The study was also intended to address a more basic issue: is it even possible to grab a handrail with sufficient speed and accuracy to prevent a fall after losing balance on a stairway? Testing of four healthy young adults demonstrated that sizeable stabilizing handrail force can be generated very quickly (up to 60% of body weight in less than 1 second) in response to loss of balance. Furthermore, these grabbing responses were clearly of functional significance, resulting in a marked reduction in the incidence of ‘falls’ (i.e. landing on the padded surface) compared to trials where the handrail was absent. The most consistent aspect of the force generation was the tendency to exert a forward axial force along the rail. An unexpected finding was that this force often appears to be exerted through a pulling, rather than pushing, action, because of the posterior location of the grip relative to the body. Although most of the force components tended to increase with perturbation magnitude, the lateral forces appeared to be most dependent on whether a step was taken. Stance leg had few effects, but variation in proximity to the rail was found to influence the angle at which the hand approached the rail. Gripping the rail prior to perturbation led to a greater tendency to pull upwards. Implications of these findings for safer handrail design are discussed.     

Disaster resilience and population ageing: the 1995 Kobe and 2004 Chuetsu earthquakes in Japan

This paper provides a framework for evaluating the effects of population ageing on disaster resilience. In so doing, it focuses on the 1995 Kobe and 2004 Chuetsu earthquakes, two major disasters that affected Japan before the 2011 Great East Japan earthquake. It analyses regional population recovery on the basis of pre‐disaster and post‐recovery demographic characteristics using defined transition patterns of population ageing. The evaluation framework demonstrates that various recovery measures make different contributions to disaster resilience for each transition pattern of population ageing. With reference to regional population ageing, the framework allows for a prediction of disaster resilience, facilitating place vulnerability assessments and potentially informing policy‐making strategies for Japan and other countries with ageing populations.     

Reducing fall risk by improving balance control: development, evaluation and knowledge-translation of new approaches

Problem

Falling is a leading cause of serious injury, loss of independence, and nursing-home admission in older adults. Impaired balance control is a major contributing factor.

Methods

Results from our balance-control studies have been applied in the development of new and improved interventions and assessment tools. Initiatives to facilitate knowledge-translation of this work include setting up a new network of balance clinics, a research-user network and a research-user advisory board.

Results

Our findings support the efficacy of the developed balance-training methods, balance-enhancing footwear, neuro-prosthesis, walker design, handrail-cueing system, and handrail-design recommendations in improving specific aspects of balance control.

Impact on Knowledge Users

A new balance-assessment tool has been implemented in the first new balance clinic, a new balance-enhancing insole is available through pharmacies and other commercial outlets, and handrail design recommendations have been incorporated into 10 Canadian and American building codes. Work in progress is expected to have further impact.     

Remediation of toxic metal contaminated soil by washing with biodegradable aminopolycarboxylate chelants

Ex situ soil washing with synthetic extractants such as, aminopolycarboxylate chelants (APCs) is a viable treatment alternative for metal-contaminated site remediation. EDTA and its homologs are widely used among the APCs in the ex situ soil washing processes. These APCs are merely biodegradable and highly persistent in the aquatic environments leading to the post-use toxic effects. Therefore, an increasing interest is focused on the development and use of the eco-friendly APCs having better biodegradability and less environmental toxicity. The paper deals with the results from the lab-scale washing treatments of a real sample of metal-contaminated soil for the removal of the ecotoxic metal ions (Cd, Cu, Ni, Pb, and Zn) using five biodegradable APCs, namely [S,S]-ethylenediaminedisuccinic acid, imminodisuccinic acid, methylglycinediacetic acid, DL-2-(2-carboxymethyl) nitrilotriacetic acid (GLDA), and 3-hydroxy-2,2′-iminodisuccinic acid. The performance of those biodegradable APCs was evaluated for their interaction with the soil mineral constituents in terms of the solution pH and metal-chelant stability constants, and compared with that of EDTA. Speciation calculations were performed to identify the optimal conditions for the washing process in terms of the metal-chelant interactions as well as to understand the selectivity in the separation ability of the biodegradable chelants towards the metal ions. A linear relationship between the metal extraction capacity of the individual chelants towards each of the metal ions from the soil matrix and metal-chelant conditional stability constants for a solution pH greater than 6 was observed. Additional considerations were derived from the behavior of the major potentially interfering cations (Al, Ca, Fe, Mg, and Mn), and it was hypothesized that use of an excess of chelant may minimize the possible competition effects during the single-step washing treatments. Sequential extraction procedure was used to determine the metal distribution in the soil before and after the extractive decontamination using biodegradable APCs, and the capability of the APCs in removing the metal ions even from the theoretically immobilized fraction of the contaminated soil was observed. GLDA appeared to possess the greatest potential to decontaminate the soil through ex situ washing treatment compared to the other biodegradable chelants used in the study.