Alessander Danna-Dos-Santos1, Maria M Ribeiro Dos Santos2, Alessandra T Magalhães3, Vinicius S Cardoso3, Patricia Driusso4, Luis Mochizuki5, Adriana M Degani6. 1. Laboratory for Advances in Rehabilitation Sciences, Department of Physical Therapy, Western Michigan University, 1903 W Michigan Av., Office # 3454, Kalamazoo, MI, 49008-5383, USA. alessander.santos@wmich.edu. 2. Brunel University, West London, UK. 3. BioSignal Laboratory, School of Physical Therapy, Federal University of Piauí, Parnaíba, PI, Brazil. 4. Physical Therapy Department, Federal University of São Carlos, São Carlos, SP, Brazil. 5. School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, SP, Brazil. 6. Laboratory for Advances in Rehabilitation Sciences, Department of Physical Therapy, Western Michigan University, 1903 W Michigan Av., Office # 3454, Kalamazoo, MI, 49008-5383, USA.
Abstract
BACKGROUND: Computerized stabilometry has been utilized to investigate the effect of vision on the neuromechanisms of human postural control. However, this approach lacks operational methods to quantify visual dependency during upright stance. This study had three goals: (1) To introduce the concept of visuo-postural dependency indices (VPDI) representing balance sway characteristics in multiple analytical domains (spatial, temporal, frequency, and structural), (2) To investigate the age and gender effects on VPDIs, and (3) To investigate the degree of relationships between VPDI and both subjective visual vertical and horizontal perception (SVV and SVH, respectively). METHODS: 102 participants (16 to 80 years old) performed bipedal stances on a force platform with eyes open and closed. Response variables included the VPDIs computed for each postural index. In addition, 29 participants also performed SVV and SVH assessments. RESULTS: Fifteen VPDIs showed to be robust indicators of visual input modulation, and the variation across their magnitudes of modulation revealed a non-homogeneous response to changes in visual stimuli. Gender and age were not found to be a significant factor to VPDI modulation. CONCLUSIONS: VPDIs revealed to be potential measures capable to quantitatively assess visuo-postural dependency and aid the assessment of fall risks and balance impairments.
BACKGROUND: Computerized stabilometry has been utilized to investigate the effect of vision on the neuromechanisms of human postural control. However, this approach lacks operational methods to quantify visual dependency during upright stance. This study had three goals: (1) To introduce the concept of visuo-postural dependency indices (VPDI) representing balance sway characteristics in multiple analytical domains (spatial, temporal, frequency, and structural), (2) To investigate the age and gender effects on VPDIs, and (3) To investigate the degree of relationships between VPDI and both subjective visual vertical and horizontal perception (SVV and SVH, respectively). METHODS: 102 participants (16 to 80 years old) performed bipedal stances on a force platform with eyes open and closed. Response variables included the VPDIs computed for each postural index. In addition, 29 participants also performed SVV and SVH assessments. RESULTS: Fifteen VPDIs showed to be robust indicators of visual input modulation, and the variation across their magnitudes of modulation revealed a non-homogeneous response to changes in visual stimuli. Gender and age were not found to be a significant factor to VPDI modulation. CONCLUSIONS: VPDIs revealed to be potential measures capable to quantitatively assess visuo-postural dependency and aid the assessment of fall risks and balance impairments.
Authors: Peter C Fino; Ahmad R Mojdehi; Khaled Adjerid; Mohammad Habibi; Thurmon E Lockhart; Shane D Ross Journal: Ann Biomed Eng Date: 2015-10-13 Impact factor: 3.934