According to a website presented by Jacob L. Driesen, Ph.D (2003), Parkinson’s disease is a neurodegenerative disease of the substantia Nigra that results in the following characteristics:
-Resting tremors also known as an action tremor. These tremors are most commonly involved with the hands and fingers. This type of tremor is often called a pill-rolling tremor because of the pattern of movement of the fingers, as if rolling a small pill between the thumb and the fingers (Love & Webb, 2001). However, they can also involve the limbs and face. However, this resting tremor is absent during sleep.
-Slow and reduced range of motion (ROM) as a result of dysfunction of the Basal Ganglia, which is not a result of muscle weakness. Bradykinesia can cause shuffling walk, lack of facial expression, difficulty with speech, writing, and other voluntary movements. There usually difficulty initiating movement with excessively rapid performance of the movement when it finally is initiated (Love et al., 2001)
-Result of increased muscle tone (muscles are in a greater than normal state of contraction). This rigidity affects the neck, trunk and limbs. The individual may present with a constant resistance to movement or an intermittent change in resistance, also known as “cogwheel resistance.” In addition, rigidity can exacerbate the already slowed and restricted movements of bradykinesia.