Research on Capitol Hill

Presenter and Co-Presenter(s)

Natalie L. Ferguson, Utah State UniversityFollow

Expected Graduation Year



Emma Eccles Jones College of Education and Human Services


Health, Physical Education, and Recreation Department

Faculty Mentor

Dr. Breanna Studenka


The structure of variability in the human neuromotor system can be indicative of its health and function (Stergiou & Decker, 2011). More regular variation in gait is found in those with an ACL injury compared to those without (Decker, et al., 2011). Many things may influence postural control including where the mind is focused during a task. Focusing on something outside the body made performance on a balance task more automatic, whereas focusing on the body induced less automatic control (Wulf, et al., 2003). We tested the influence of attentional focus on non-linear aspects of postural sway post ACL injury. Participants stood on a force plate standing as still as possible, keeping the injured knee as still as possible, keeping the uninjured knee as still as possible, or keeping a laser beam as still as possible. Sample Entropy was measured for medial lateral sway, anterior posterior sway, and average displacement of the center of pressure from the mean. A 2 group (injured vs. non-injured) by 4 task (no focus, focus on injured knee, focus on uninjured knee, external focus) ANOVA was run to compare groups and tasks. Those in the ACL group had significantly more irregular sway than the non-injured group for anterior-posterior sway and average displacement. The ACL group, but not the no-injury group, had significantly more irregular average displacement during the external focus task compared to the internal focus tasks. These results lend support for the influence of attentional focus in rehabilitation settings.


Decker, L.M., Moraiti, C.O., Stergiou, N., & Georgoulis, A.D. (2011). New insights into anterior cruciate ligament deficiency and reconstruction through the assessment of the knee kinematic variability in terms of nonlinear dynamics. Journal Articles. Paper 89.

Stergiou, N., & Decker, L. M. (2011). Human movement variability, nonlinear dynamics, and pathology: Is there a connection?. Human Movement Science, 30(5), 869-888.

Wulf, G., Weigelt, M., Poulter, D., McNevin, N., (2003). Attentional focus on suprapostural tasks affects balance learning. The Quarterly Journal of Experimental Psychology Section A: Human Experimental Psychology. 56(7), 1191-1211.

First Co-Presenter's Department

Health, Physical Education, and Recreation Department

Document Type


Publication Date




To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.