Which of the following is NOT a manifestation of hypokinesia in individuals with Parkinson's Disease?

The presence of progressive loss of olfactory function in individuals with Parkinson's Disease is not considered a manifestation of hypokinesia. Hypokinesia refers to a reduction in movement amplitude or speed, which directly affects motor functions and physical actions.

The other options listed are related to hypokinesia because they involve a decrease in physical amplitude or movement. Loss of loudness of speech, termed hypophonia, indicates a reduction in the amplitude of vocalization, which is clearly a manifestation of hypokinesia as it reflects diminished motor control over speech production. Similarly, loss of amplitude in handwriting, known as micrographia, showcases reduced movements in the hand and fingers while writing, also linking to hypokinesia. Lastly, shortening of stride length during walking is another physical manifestation of hypokinesia, highlighting decreased movement amplitude in the legs during gait.

In contrast, the progressive loss of olfactory function mainly relates to sensory processing and is not a movement-related symptom, making it distinct from manifestations that specifically involve hypokinesia.