Dynamic control of posture across locomotor tasks

Abstract

Successful locomotion depends on postural control to establish and maintain appropriate postural orientation of body segments relative to one another and to the environment, and to ensure dynamic stability of the moving body. This paper provides a framework for considering dynamic postural control, highlighting the importance of coordination, consistency, and challenges to postural control posed by various locomotor tasks such as turning and backward walking. The impacts of aging and various movement disorders on postural control are discussed broadly in an effort to provide a general overview of the field and recommendations for assessment of dynamic postural control across different populations in both clinical and research settings. Suggestions for future research on dynamic postural control during locomotion are also provided and include discussion of opportunities afforded by new and developing technologies, the need for long-term monitoring of locomotor performance in everyday activities, gaps in our knowledge of how targeted intervention approaches modify dynamic postural control, and the relative paucity of literature regarding dynamic postural control in movement disorder populations other than Parkinson disease.

The clinical significance of freezing while turning in Parkinson’s disease

“…Turning is often impaired in PD even in the early, untreated phase of the disease (Zampieri et al, 2010). In fact, subjects with PD often show longer turn durations and a greater number of steps to complete a turn, even when straight ahead walking speed is normal (review (Earhart, 2013)). These turning impairments might be associated with a compromised ability to change motor patterns from straight walking to turning (Earhart, 2013).…”

“…In fact, subjects with PD often show longer turn durations and a greater number of steps to complete a turn, even when straight ahead walking speed is normal (review (Earhart, 2013)). These turning impairments might be associated with a compromised ability to change motor patterns from straight walking to turning (Earhart, 2013). Interestingly, we only observed a slight increase in the Freezing Ratio and clinical ratings in FoG+ compared to FoG− during the ITUG test, indicating that 180-degree turns in the ITUG are not sufficient to elicit FoG.…”

Cognitive Enhancement

“…Despite the motor impairments suffered by PD patients, many retain the ability to participate in exercise activity (Earhart 2013), in some cases resulting in demonstrable cognitive benefit. In a community-dwelling group of PD patients, regular walking resulted in improved motor function, cognition and general quality of life (Uc et al 2014), while exercise improved cued reaction time, indicative of cognitive improvement, in another group of PD patients (Ebersbach et al 2014).…”

Locomotor corollary activation of trigeminal motoneurons: coupling of discrete motor behaviors

“…In vertebrates, such coupling is observed for respiration (Bramble and Carrier, 1983), eye movements (Lambert et al, 2012), tail motion (Wada et al, 1993) or phase-locked arm and trunk motor adjustments (Earhart, 2013). While some coupled motor behaviors such as tail motion, e.g.…”