Biomechanical and Sensory Constraints of Step and Stair Negotiation in Old Age
The majority of falls in the elderly occur during stair descent. Several functional parameters, including muscle strength, joint mobility and our sense of balance, may be involved, all of which deteriorate with age. The aim of this programme is to understand the role played in stepping performance by musculoskeletal and sensory functions and their deterioration with ageing and to find ways of improving the ability of older people to descend stairs.
The first approach will be to examine the design of stairs, specifically the combination of step-rise and step-going, since older people may lack the strength to cope with high steps or have difficulty landing safely on narrow steps. The results of this study could lead to alterations of the current building regulations relating to stair design. The second approach is to see to what extent “tailor-made” exercise training, for both strength and skill deficits identified in older people, can minimise the age-related deterioration of stepping ability. It is anticipated that this investigation will result in guidelines concerning the efficacy and cost effectiveness of training interventions.
Constantinos Maganaris, Manchester Metropolitan University
Vasilios Baltzopoulos, Manchester Metropolitan Universtiy
Mike Royce, British Research Establishment
The overall aim of this programme is to understand the role played in stepping performance by musculoskeletal and sensory functions and their deterioration with ageing and to find ways of improving the ability of older people to descend stairs. To achieve this, the specific objectives are:
To quantify the impact that factors such as deteriorating muscle strength, joint flexibility, balance and motor control have on the ability to safely descend stairs in old age.
To identify the optimum design of stairs for safe negotiation by elderly people.
To determine the extent to which the identified biomechanical and physiological constraints on stair descent can be minimised with “tailor-made” exercise interventions.
Three studies will address these points. Study 1 will identify the contribution that biomechanical factors such as muscle strength and range of motion make to safe stair descent. Study 2 will examine the design of stairs to see if changing the going and rise matches better the capabilities of elderly people and improves safety when they negotiate stairs. This study will also identify individuals who may have biomechanical limitations and those where motor control and coordination are the main problems. The final Study 3, will take subjects, identified in Study 2 as having either biomechanical limitations or problems with balance and coordination, and provide appropriate training to see how effective this is and to what extent it might be used on a larger scale.
Fifty older participants (>65 y), including individuals with a history of falls, and fifty younger participants ( < 40 y) will be tested on a staircase with adjustable step-going and step-rise, previously used by our consultant at the BRE.
For Study 1, the staircase will be implemented with force plates, and kinematic data will be recorded with an optoelectronic system. The measured joint angles and the calculated forces during the descent tasks will be compared with values of maximum force and maximum range of motion in isolated tests, so that indexes of muscle strength and joint mobility reserves can be quantified.
In Study 2, the optimum combination of step-rise and step-going will be identified from analysis of the kinematic data, quantifying stepping errors such as missteps, hesitations, use of handrail and glances at feet. Fear of falling will be assessed from questionnaire scores.
In Study 3, older individuals for whom an increased step-rise causes difficulties will be identified. They will be considered as having mainly musculoskeletal problems and they will undergo eight weeks of knee and ankle muscle strengthening and ankle joint flexibility. Older individuals with difficulties in reduced step-going values will be considered as having mainly motor control and balance problems and they will perform eight weeks of balance training and stair descents with corrective feedback and supervised practice. The two exercise groups will be re-tested on the BRE stairs after completion of their training using stair settings identified as “challenging” when first tested to see whether the “tailor-made” interventions were effective.
At the end of this project we will be able to recommend the optimum combination of going to rise for older people. Such recommendations could become part of the general building regulations and have a significant impact on the physical safety and the confidence of older people.
The outcome of Studies 1 and 2 will identify the relative importance of a range of biomechanical and physiological factors that adversely affect stepping performance. This information will inform the nature of the interventions outlined in Study 3.
Study 3 will indicate the extent to which training for strength, flexibility, balance or motor skills can improve performance. This information is essential for any cost/benefit analysis of possible future large-scale population-based interventions.
Falls, and fear of falling, are major factors affecting the mobility and quality of life for the elderly, and it is descending steps and stairs in the home, gardens, public spaces and on public transport, where problems occur most frequently. The aim of our project is to find ways of improving the competence and confidence of older people when descending steps and stairs. Our programme of work meets the primary NDA objective to “develop practical policy and implementation guidance along with novel scientific, technological and design responses to help older people enjoy better quality lives.” We are addressing a major problem for older people. Our approach to this question is novel and multidisciplinary in that it touches on the perceptions and fears of falling, and examines the involvement of biomechanical and motor control factors, as well as stair-design aspects. Our findings may lead to the implementation of policy in the shape of new building regulations through our connections with British Research Establishment (BRE) and recommendations about the efficacy of training programmes.
Beneficiaries. The present project will be of direct benefit to:
To achieve the above targets, the results of the project will be disseminated to the scientific community through publications in peer-review academic journals and presentations in scientific meetings. Dissemination will also involve publication of articles in magazines and local newspapers and leaflets for the non-academic community, local community, GR surgeries and physiotherapy clinics, the University of Third Age (U3A) and relevant charitable organisations working with older people (e.g., Age Concern).