OK, this might show that they are in fact the same, albeit slower? or that they might be different but due to the speed as in walking whereby contralateral arm swing is dependent on gait speed.

Perhaps you could look at the differences as you have described without any time frame but analyse the angular velocities and time between each component (as well as range/excursion of movement). Then if different you would have to consider 1. Is this due to speed of standing? or 2. Is it to do with the disease process as it relates to factors such as muscle weakness?

You could then ask the normals and patient population to rise from sitting to a count (or counts and vary the timing of the counts from slow to "normal"). You could vary the count to see if the normals and parkinson's patients became more similar as their speeds of rising became the same. This might conclude that speed is the factor and therefore teaching to rise with a certain speed might be more beneficial than anything else. This could later be looked at (PHD) in relation to medication to facilitate the freedom of movement to permit the more idea speed of rising.

Does this make sense?