Which term refers to decreased amplitude and velocity of voluntary movement?

Bradykinesia refers to a clinical condition characterized by a significant reduction in the speed and amplitude of voluntary movements. This term is often associated with neurological disorders such as Parkinson's disease, where patients may experience slow and small movements, affecting their ability to initiate and perform everyday activities.

In bradykinesia, the decreased amplitude signifies that even when movements are made, they are smaller than typical, while reduced velocity indicates that these movements take longer to complete. This combination leads to challenges in motion and can impact the overall quality of life, as individuals may find it harder to engage in tasks that require coordinated and timely movements.

The other terms have distinct meanings that do not align with this particular description. Asthenia refers to a general muscle weakness or lack of energy, akinesia describes a complete loss of voluntary movement, and spasticity is characterized by abnormal muscle tightness or stiffness, which is different from the effects of bradykinesia. Understanding these terms helps clarify the specific ways in which movement can be affected in various neurological and muscular disorders.