Park E1
1University of North Georgia, Department of Physical Therapy, Dahlonega, United States
Background: A recent investigation of postural control during quiet standing suggested that the stability upright stance results from movement coordination of multiple joints along the body axis rather than being the result of a simple ankle joint or ankle-hip control strategy, combining with the stiffening of other joints. However, more information will be needed to understand the upright standing posture control in the framework of the multi-joint coordination.
Purpose: The current work provides additional information for this hypothesis by showing that dominant and non-dominant side control will have not have the same profile for the covariation of multiple joints.
Methods: 16 college students (8 right-handed, 8 left-handed) were volunteered to participate in this study. Subjects either stood quietly for 2-minute trials each in three conditions: (1) Normal quiet standing, (2) standing with eyes closed, (3) standing on a narrow base of support. Movements of their body segments will be captured with a 12 camera Qualysis motion measurement system, and two force-platforms measure ground reaction force (GRF) and a center of pressure (COP). The Uncontrolled Manifold (UCM) Analysis will be applied to partition joint variance into 'good' variance(VUCM), which reflects the use of motor equivalent joint combinations consistent with a stable value of the GRF and COP position of both right and left sides across time, and 'bad' variance (VORT), which leads to variability of the GRF or COP position for both sides. The relative difference between the two variance components (DVAR= VUCM-VORT/VUCM+VORT) will reflect the use of motor abundance (i.e. many equivalent elemental variable combinations) to stabilize the performance variable.
Results: Results based on the original joint angles are consistent with previous studies, revealing that “good” variance was substantially larger than “bad” variance during quiet standing for both dominance and non-dominance side. From the relative differences between the two variance components results, a dominance side has higher use of motor abundance compare to the non-dominance side.
Conclusion(s): We conclude that the dominance side has more flexible solutions to stabilize the COP and GRF during upright standing.
Implications: This study helps to understand the roll of dominance and non-dominance side for upright standing posture. A better understanding of the mechanisms of upright standing posture will provide an important information to prevent fall, potentially could lead to improve evaluation and training program.
Keywords: Standing posture, Uncontrolled Manifold analysis
Funding acknowledgements: Internal Funding from the University of North Georgia
Purpose: The current work provides additional information for this hypothesis by showing that dominant and non-dominant side control will have not have the same profile for the covariation of multiple joints.
Methods: 16 college students (8 right-handed, 8 left-handed) were volunteered to participate in this study. Subjects either stood quietly for 2-minute trials each in three conditions: (1) Normal quiet standing, (2) standing with eyes closed, (3) standing on a narrow base of support. Movements of their body segments will be captured with a 12 camera Qualysis motion measurement system, and two force-platforms measure ground reaction force (GRF) and a center of pressure (COP). The Uncontrolled Manifold (UCM) Analysis will be applied to partition joint variance into 'good' variance(VUCM), which reflects the use of motor equivalent joint combinations consistent with a stable value of the GRF and COP position of both right and left sides across time, and 'bad' variance (VORT), which leads to variability of the GRF or COP position for both sides. The relative difference between the two variance components (DVAR= VUCM-VORT/VUCM+VORT) will reflect the use of motor abundance (i.e. many equivalent elemental variable combinations) to stabilize the performance variable.
Results: Results based on the original joint angles are consistent with previous studies, revealing that “good” variance was substantially larger than “bad” variance during quiet standing for both dominance and non-dominance side. From the relative differences between the two variance components results, a dominance side has higher use of motor abundance compare to the non-dominance side.
Conclusion(s): We conclude that the dominance side has more flexible solutions to stabilize the COP and GRF during upright standing.
Implications: This study helps to understand the roll of dominance and non-dominance side for upright standing posture. A better understanding of the mechanisms of upright standing posture will provide an important information to prevent fall, potentially could lead to improve evaluation and training program.
Keywords: Standing posture, Uncontrolled Manifold analysis
Funding acknowledgements: Internal Funding from the University of North Georgia
Topic: Human movement analysis
Ethics approval required: Yes
Institution: University of North Georgia
Ethics committee: Troy Smith
Ethics number: 2017-48-C&U
All authors, affiliations and abstracts have been published as submitted.
