The Role of Anticipatory Postural Adjustments in Balance Control: Effects of Age and Training

The objective of this thesis was to understand the role of anticipatory postural adjustments (APAs) in compensatory control of posture in healthy young and older adults and the effect of training on the generation and utilization of APAs. Five experiments involving 21 healthy young and 10 healthy older adults were conducted. External predictable and unpredictable perturbations of identical magnitude were applied at the shoulder level. Electrical activity of trunk and leg muscles, ground reaction forces, and kinematic data were recorded and analyzed for the anticipatory and compensatory phases of postural control. The first study investigated the role of APAs in subsequent control of posture in healthy young adults. The second study examined the differences in APAs between young and older adults as well as the effect of aging on the ability to use APAs in subsequent control of posture. The fourth and fifth studies investigated the immediate effects of training in improving the generation of anticipatory postural adjustments and their utilization in subsequent balance control of healthy young and older adults. The outcomes of these studies, while highlighting the role of anticipatory postural adjustments in balance control, also provide a background for rehabilitation interventions focused on long-term training of balance control in the elderly and people with neurological impairments.