Protective stepping is crucial for balance control and recovery. A step made to restore balance must have the right timing, direction and size for it to succeed. Initial studies have shown that inappropriate step responses are significantly more prevalent in older compared to younger people. Impaired stepping is even more common in older people at risk of falls and those with balance impairments, suggesting that appropriate stepping responses are crucial for falls prevention. However, no studies have comprehensively examined stepping performance as a risk factor for falls in a prospective study.
We propose to systematically investigate sensory, motor, neural, mechanical and psychological determinants of appropriate and impaired responses to postural perturbations and determine the role that impaired stepping plays in falls. Much of this work will be addressed in a large prospective cohort study, with two targeted experimental studies undertaken to identify the effects of fatigue and divided attention on stepping performance and balance control. The final study will comprise an RCT to evaluate the effects of a training intervention to improve balance and stepping performance in older adults. This body of work will provide the framework from which to conduct a subsequent RCT with falls or fall injuries as the primary outcome measure.
Stepping will be assessed using a novel multi-directional wait-pull perturbation protocol that initiates a step response in an unexpected direction and time. This research comprises four distinct studies.
It is hypothesised that impaired stepping will be an important risk factor for falls in older adults. A systematic and comprehensive approach to quantification of risk will reveal complex non-linear associations and interactions between the stepping measures and a range of measured physiological, pathological, psychological and sociological factors. Our proposed project will develop an explanatory model of impaired stepping and falls. We will develop a low tech test suitable for use in clinical practice to enhance falls risk assessment, and lay a solid foundation from which exercise programs can be enhanced to provide safe, appropriate and effective interventions.
