Are you a smooth mover?
To move your body smoothly, you have to move your muscles in the right order, and stop one movement before starting another. Scientists think that an area of your brain called the basal ganglia is crucial for the overall control of sequences of movements. Damage to different parts of this area, as occurs in Parkinson’s and Huntington’s diseases, causes difficulties in planning and performing movements.
How does Huntington’s disease affect movement?
People with Huntington’s disease suffer from jerky, random movements, and spasms of their limbs, neck and body. Other symptoms include changes in mood, personality and memory. An area of the brain gradually wastes away as the disease progresses, including part of the basal ganglia. This seems to cause a loss of control of movements: muscles normally held in check start contracting randomly.
How does Parkinson’s disease affect movement?
People with Parkinson’s disease can have a combination of symptoms: slow movements, constant tremor, stiff muscles and limbs, and an expressionless face. As the disease progresses, an area of the brain's basal ganglia gradually wastes away. This causes difficulty in preparing for, and starting, movements. However, once they have overcome the initial resistance, they can move more smoothly.