Marsden ball is a very versatile activity. It may be used for a range of purposes. The most common purpose for Marsden ball is to train localization.
Localization is pinpointed with this activity through ball taps. This is done by hanging the ball at the patient's belly button height. The patient and the therapist will hit the ball back and forth in a few different ways. The patient will start by tapping the ball back and forth using the palm of their hand. This requires the patient to make contact with the moving target, which requires them to know where the moving ball is in space.
The next level would be for the patient to tap the ball with three fingers. This makes the activity slightly harder as it lowers the surface area of the point of contact with the ball. The patient is forced to be more precise about their movements.
Lastly, the patient can make it even more difficult by tapping the ball with only their index finger. This significantly lowers the point of contact's size, and it is, therefore, a higher difficulty.
Like any other activity, Marsden ball taps can be patched and/or unpatched, depending on whether you are focusing on strengthening the localization of one eye at a time or both.
Another option is loading this activity. While performing the ball taps, the therapist may ask the patient to name a color every time they tap it or say their ABCs, for example. This can make the activity more challenging due to the multitasking component.