Diminished postural stability in older adults and individuals with Parkinson’s disease might stem not from insufficient, but rather from excessive brain and muscle activity, as reported on March 25th in the journal Science Daily.
The study indicates that when attempting to regain balance, the brain and muscles in the elderly exhibit an overactive response even to minimal perturbations in stability. Paradoxically, this hyper-reactivity does not enhance, but instead impairs the ability to maintain equilibrium.
Researchers led by Lena Ting investigated alterations in the body’s response to sudden loss of balance. In prior experiments involving young subjects, the scientists simulated abrupt instability, such as the sudden removal of a supporting surface. This elicited a rapid, reflexive action involving the brainstem and musculature, with an additional surge of activity occurring under greater external force.
The current research focused specifically on older individuals and Parkinson’s patients. It was discovered that even minor postural disturbances trigger heightened activity in their brains and muscles. According to Ting, the more cerebral resources demanded to maintain balance, the poorer a person’s capacity to restore stability becomes.
Furthermore, the investigators observed a change in muscular coordination: when one muscle group activated, its opposing counterpart frequently tensed simultaneously. This “conflicting” muscle engagement results in excessive movement rigidity and reduces efficiency, which is directly linked to deteriorated balance.
The authors suggest that this newly identified mechanism could form the basis for novel methods to assess fall risk. In the future, measuring muscular response to sudden stability challenges might allow for indirect assessment of an individual’s level of brain activity. This could enable the proactive identification of at-risk individuals and the prescription of targeted exercises to improve their stability.
Medical Xpress reported on March 19th regarding sustained physical activity leading to enhanced functional capacity. According to that research, maintaining a high level of mobility throughout one’s lifespan directly correlates with the ability to perform efficiently in later years.
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