Growing Healthier

It is widely accepted that physical activity is beneficial for the elder person to reduce the risk of coronary heart disease, hypertension, type 2 diabetes, osteoporosis, stroke, anxiety and depression but many forms of exercise are unsuitable for the elderly or they quit after a short period of time through lack of motivation or desire to attend a gym (American College of Sports Medicine, 2004; Hui and Rubenstein, 2006; Lee et al, 1991). However, gardening is an activity which many elderly people enjoy (Yusuf et al, 1996), rather than doing it for therapeutic reasons. The potential benefits of gardening as a form of age-appropriate exercise has particular emphasis on maintaining strength and flexibility to avoid fractures resulting from falls or osteoporosis. The gardening activities considered included digging, weeding, pruning, wheelbarrow operation, lifting of heavy objects, lawn mowing and raking. This project has measured the movement and loads placed on gardeners during a range of gardening activities and calculated the consequential forces occurring within the muscles, tendons, joints and bones of the gardener. The motion of gardeners was measured using a 12 camera 3-dimensional optical tracking system. The forces acting between the gardening equipment and the gardener was measured using force transducers, static weight plus inertia forces. The loads generated within the gardener were calculated using the Biomechanics of Bodies (BoB) software (Shippen & May 2010). The musculoskeletal model within BoB consists of 36 rigid segments connected with 33 joints whose actions represent their anatomical counterparts and 606 locomotor muscle units. The torques occurring at the joints were calculated using a Lagrangian inverse dynamics method. The force distribution within the muscles were calculated by minimising an objective function defined as the sum of the squares of the muscle activations constrained by the muscle torque equalling the inverse dynamics torque. This study suggests techniques and tool design to minimise the injury risk for the gardener.