The characteristic symptoms of moderate Parkinson's disease can be remembered with the acronym TRAP:

T--Tremor: Involuntary trembling of the limbs
R--Rigidity: Stiffness of the muscles
A-- Akinesia:  Lack of movement or slowness in initiating and maintaining movement
P-- Postural instability:  Characteristic bending or flexion of the body, associated with difficulty in balance and disturbances in gait

http://www.umm.edu/parkinsons/signs.htm?gclid=CIC7_bHy660CFdCP7Qod2SDd3w