“Theoretically each person could use different muscle activation patterns for a task, yet we all seem to use similar strategies as we age.”
Our bodies already start to age around our mid-twenties. Initially we won’t notice much of this healthy decline, due to our physical and functional redundancy. We call the physiological abilities of the neuromusculoskeletal system capacity. The difference between the task demand and the capacity is what we call reserve, which is the physical redundancy. When our capacity declines, functional redundancy allows us to compensate (or adopt) so that we can still perform the task at hand. With the use of existing theories from different fields, we produce frameworks and hypotheses on how ageing affects our movements and behaviour.
The treatment of age-related mobility impairments is increasingly relevant in our ageing societies. Age-related progression of neuromuscular decline often lead to incorrect or insufficient compensation strategies. Moreover, compensation strategies can be a valuable detection mechanism. Predictive neuromuscular simulations can become an effective tool for discovering those strategies, enabling clinicians to design treatments that are both more effective and efficient for prolonging the mobility of the patient. We develop predictive neuromuscular models that can simulate realistic daily life activities to test how a reduction in capacity results in compensation strategies.
The question is how within our redundancy humans select their movement strategies. Since humans and animals all select comparable activation patterns for the same task, there seems to be some sort of optimization for which a movement is selected (optimal control theory). We know from gait studies that human walk at a speed that requires least energy per distance. However, we think that there are other movement objectives in play for elderly people and patients, like pain avoidance, or a fear of falling. With experiments we aim to reveal these strategies and objectives in daily life activities
- van der Kruk, E., Silverman, A. K., Koizia, L., Reilly, P., Fertleman, M., & Bull, A. M. (2021). Age-related compensation: Neuromusculoskeletal capacity, reserve & movement objectives Journal of Biomechanics
- Poster: van der Kruk, E., & Geijtenbeek, T. (2021) Predictive Neuromuscular Simulation of the Sit-to-Walk movement, Dynamic Walking Conference.
- Van der Kruk, E., Anne K. Silverman, Peter Reilly, Anthony M.J. Bull (2021). Compensation due to age-related decline in sit-to-stand and sit-to-walk Journal of Biomechanics
- Poster: van der Kruk, E. & Bull, A.M.J., (2021) Movement Objectives in the Sit-to-Walk task, Dynamic Walking Conference