In order to design effective interventions to prevent age-related mobility loss, it is important to identify influencing factors. The concept of "motility" by Kaufmann et al. subdivides such factors into three categories: "access", "skills", and "appropriation". The aim of this study was to assemble appropriate quantitative assessment tools for the assessment of these factors in frail older adults and to get first insights into their relative contribution for life-space and physical activity-related mobility. This is an exploratory cross-sectional study conducted with twenty-eight at least prefrail, retired participants aged 61-94. Life-space mobility was assessed using the "University of Alabama at Birmingham Life-space Assessment" (LSA) and physical activity using the "German Physical Activity Questionnaire" (PAQ50+). Factors from the category "appropriation", followed by factors from the category "skills" showed the strongest associations with the LSA. Factors from the category "access" best explained the variance for PAQ50+. This study's findings indicate the importance of accounting for and examining comprehensive models of mobility. The proposed assessment tools need to be explored in more depth in longitudinal studies with larger sample sizes in order to yield more conclusive results about the appropriateness of the motility concept for such purposes.
Keywords: aging; frailty; life-space assessment; mobility determinants.