Gait Analysis and Prism Assessments
A gait analysis with prism assessment is an essential step in deciding if a particular type of prism is appropriate for an individual’s neuro-visual rehabilitation as a means to modify their visual spatial processing to improve balance, posture, and reduce risk of fall.
Research has shown that following a neurological event such as a traumatic brain injury, stroke, and neurological conditions including cerebral palsy, Parkinson’s disease, and multiple sclerosis that a shift in visual midline can directly affect spatial orientation, posture, and balance.1 This has been termed visual midline shift syndrome (VMSS) or alternatively has been referred to as altered egocentric localization.2 Visual midline shift syndrome alters a pre-conscious (i.e., ambient) visual process which organizes with touch (i.e., proprioception), movement of muscles and joints (i.e., kinesthesia) and balance to create an understanding of what it is like to be upright against gravity and move through space efficiently.3 This often results an individual feeling dizzy, disoriented, or being pulled/drifting to one side while walking and ultimately can increase an individual’s risk of fall.
The use of lenses, prisms, and vision therapy have been shown to modify one’s ambient visual process to more appropriately organize their visual world which can improve posture, balance and reduce risk of fall as well as alleviate dizziness.1. By modifying the information being provided to the brain for spatial information, an individual will be able to more appropriately utilize their conscious visual processing (i.e., the where and what am I looking at) without experiencing symptoms of dizziness, disorientation, etc.4 In particular, a certain form of prism prescription (yoked prisms), have been shown to reduce drift and equalize weight transfer to both sides of the body through ambulation.5 Even small amounts of yoked prism can have dramatic changes in an individual’s gait and weight transfer with dynamic movement and is an important consideration for any patient experiencing dizziness, disorientation with ambulation or a patient who finds themselves drifting to one side while walking.6
To accurately prescribe yoked prism as a part of one’s visual treatment plan, a gait analysis is required. There a variety of ways in which an individual’s gait may be analyzed which include both observational and objective measuring techniques utilizing various technologies including but not limited to walking mats and pressure sensing socks.1,5 At Excel Neuro-Optometric Institute, we utilize videographic documentation to assess the changes in gait patterns with the use of differing prism powers and orientations. This allows our clinician’s to precisely identify the power and orientation of yoked prisms that is most appropriate for the individual.
1. Padula, W. V., Subramanian, P., Spurling, A., & Jenness, J. (2015). Risk of fall (RoF) intervention by affecting visual egocenter through gait analysis and yoked prisms. NeuroRehabilitation, 37(2), 305–314.
2. Ciuffreda, K. J., Tannen, B., Ludlam, D., & Yadav, N. K. (2018). Basic neuro-optometric diagnostic tests for mild traumatic brain injury/concussion: A narrative review, perspective, proposed techniques and protocols. Vision Development & Rehabilitation, 4(4), 157–169.
3. Padula, W. V., Munitz, R., & Magrun, W. M. (2012). Chapter 7: Visual Midline Shift Syndrome. In Neuro-Visual Processing Rehabilitation: An interdisciplinary approach (pp. 78–89). essay, Optometric Extension Program Foundation.
4. Padula, W. V., Capo-Aponte, J. E., Padula, W. V., Singman, E. L., & Jenness, J. (2017). The consequence of spatial visual processing dysfunction caused by traumatic brain injury (TBI). Brain injury, 31(5), 589–600.
5. Padula, W. V., Nelson, C. A., Padula, W. V., Benabib, R., Yilmaz, T., & Krevisky, S. (2009). Modifying postural adaptation following a CVA through prismatic shift of visuo-spatial egocenter. Brain injury, 23(6), 566–576.