CENTER OF MASS DYNAMICS AND PERFORMANCE OF VERTICAL HOPPING IN FEMALES WITH CHRONIC ANKLE INSTABILITY
Alyssa Parten1, Jeffrey Simpson2, Hunter Waldman1, Nicole Rendos3, Hoon Kim4, John Harry5. 1University of North Alabama, Florence, AL. 2University of West Florida, Pensacola, FL. 3Emory University, Atlanta, GA. 4University of North Carolina-Chapel Hill, Chapel Hill, NC. 5Texas Tech University, Lubbock, TX.
BACKGROUND: Chronic ankle instability (CAI) is a condition involving subjective feelings of the ankle ‘giving way’, pain, and decreased self-reported function. Single limb hopping tests are used to identify motor-behavioral impairments of the lower limb that are associated with CAI, but are often limited by rudimentary metrics. The current study aimed to evaluate center of mass (COM) dynamics to further understand performance of single limb vertical hopping in females with and without CAI. METHODS:Females with CAI (n=11; age: 25±4 y, height: 162.6±13.6 cm, mass: 69.6±15.6 kg) and controls (n=11; age: 25±5 y, height: 170.4±5.1 cm, mass: 65.8±4.1 kg) completed 3 trials of 5 consecutive single limb vertical hops on a force platform. Mathematical integration of vertical ground reaction force data was used to estimate vertical COM velocity and vertical COM position during the hopping trials. Time to completion, hop height, ground contact time, reactive strength index (RSI), vertical COM depth, and vertical stiffness were compared between groups with an unpaired t-test (p<0.05) and effect sizes (ES). RESULTS: Significantly less RSI (p=0.045; ES=0.76; CAI: 0.12±0.05 vs. Control: 0.16±0.06) and less vertical stiffness (p=0.014; ES=1.09; CAI: 99.32±17.83 vs. 132.91±43.56 N/kg/m) were observed in the CAI group. CONCLUSION: Lower RSI scores and reduced vertical stiffness suggests a more compliant lower limb and highlights a less efficient transfer of lower limb mechanical output during repetitive hopping in females with CAI.
Parten, A; Simpson, J; Waldman, H; Rendos, N; Kim, H; and Harry, J
"CENTER OF MASS DYNAMICS AND PERFORMANCE OF VERTICAL HOPPING IN FEMALES WITH CHRONIC ANKLE INSTABILITY,"
International Journal of Exercise Science: Conference Proceedings: Vol. 16:
1, Article 187.
Available at: https://digitalcommons.wku.edu/ijesab/vol16/iss1/187