Recent studies have demonstrated that the relationship between cognitive and sensori-motor functioning is becoming stronger during aging, suggesting that common mechanisms could be responsible for age-related decline in cognitive and sensori-motor performance. Quantitative variations in aging, such as decreased information processing speed have been proposed as a common cause to explain cognitive and sensori-motor slowing. However, we do not know how these quantitative variations can influence the qualitative changes during aging. The main objective of this thesis was to describe age-related strategic changes in the sensori-motor domain and furthermore to determine whether these strategic changes in the sensori-motor domain share similar strategic variations with cognitive domain. To achieve this objective, a total of five studies were conducted where both young and older adults performed the Fitts' task. Our data replicated previous findings relative to those observed in the cognitive domain. On the one hand, age-related differences in strategy repertoire, strategy distribution and strategy execution were found. On the other hand, phenomenon associated with these variations, such as strategy sequential difficulty effects were also observed, suggesting involvement of common resources (i.e., executive functions). Additionally, we showed an amplification of these strategic variations in pathological aging and an improvement in strategic execution after training. These results provide a better understanding of the underlying cognitive mechanisms in young and older adults’ sensori-motor behavior during the Fitts’ task.