Timothy C. Hain, MD • Page last modified: July 30, 2022
Bouncing on Swiss balls or mini-tramps may be advocated to build up the otolith-ocular reflex as well as otolith-postural reflexes. Again, this might be a good idea, but we are presently lacking any reasonable way to measure the otolith-ocular reflex and also we have little idea as to it's significance in daily life. There are essentially no situations in which otolith function is selectively eliminated in humans. Thus, there are no "experiments of nature" with which one might decide whether this protocol is useful. It would be interesting to see if this procedure is associated with improved outcome, as compared to another activity (such as perhaps weight-lifting).
Patients may be urged to track objects that are moving in counterphase to their heads, generally moved by themselves. This procedure might encourage patients to use both visual tracking and vestibular stabilization in tandem. There is no natural situation that this exercise might help them with. Similarly, patients may be asked to track objects that are moving with their heads. This procedure might encourage patients to turn off their vestibular system. This might, in theory, be useful for persons with vestibular imbalance such as those with Meniere's disease. It would be unlikely to be helpful in persons who already have their vestibular system turned off (i.e. persons with bilateral vestibular loss).
Axial weight loading has been tried in cerebellar ataxia, but effects on gait are inconsistent (Clapton et al, 2003). The rationale was that axial loading increases proprioceptive feedback, or that changes the moment of inertia. An increase in the moment of inertia might slow a movement, allowing more time for control. Many therapists continue to use weights on the limbs or axially. Little data is available about limb weighting.
Following the same train of thought as the visual dependency exercises, perhaps it might be of benefit for someone to practice maintaining their balance in situations where somatosensory (ankle and pressure) input is either unreliable or just not there. Some authors have suggested that a particular type of motion sickness syndrome, Mal de Debarquement, is due to overreliance on somatosensory input. We are dubious about this, but it provides a place to start.
Somatosensory input can be distorted using tilt-boards, rails, slabs of foam, or just by walking on the beach. Forcing someone to do this might encourage them to recalibrate and rely to a greater extent on their vestibular or visual sensory inputs. Is this a good idea ? Based on experience, it probably is -- more studies are needed though.
If one exposes oneself to something over and over, one may get "used to it". In physiology, this is called habituation, and it works for dizziness too. Examples of this approach are the "Norre" exercises, and the "Kitchen sink" approach to dizziness.
The main problem with this approach is that it takes a long time and it is difficult to tolerate the repetitive motion needed to make an impact.
A recent attempt to use habituation for motion intolerance is the "Puma method". This is an arduous series of exercises that may habitutate the vestibular system. So far, nobody has proven that it works, but it looks promising. Persons who have tried it in my practice have indicated that it is very difficult to tolerate.