Final answer:
The increased risk of falling for a Parkinson's disease patient is due to an unsteady, shuffling gait caused by the loss of dopamine neurons affecting the regulation of movement, leading to postural instability and slowness of movement.
Step-by-step explanation:
Patients diagnosed with Parkinson's disease face an increased risk of falling due to their unsteady, shuffling gait. This characteristic symptom is part of the motor signs that define the disease, which includes muscle tremor, rigidity, slowness of movement, and postural instability.
The loss of dopamine neurons in the substantia nigra, a part of the brain that regulates movement, leads to a slow, hunched, shuffling walk and balance and posture problems, which can greatly increase the likelihood of falls. While other symptoms such as psychological changes like dementia and emotional problems are associated with Parkinson's disease, it is the physical symptoms that primarily contribute to being prone to falls.