title: Individuals with chronic ankle instability exhibit decreased postural sway while kicking in a single-leg stance.
abstract: Individuals with chronic ankle instability (CAI) usually experience deficits in balance control, which increase displacement in the body's center of pressure (COP) when they balance on a single leg. Little is known, however, about whether or not these individuals use the strategies of postural adjustment properly, especially during functional tasks that may predispose them to ankle sprain. The aim of this study was to investigate anticipatory (APA) and compensatory (CPA) postural adjustments in individuals with and without CAI as they kick a ball while standing in a single-leg stance with their ankle in neutral and supinated positions. COP displacements were calculated and their magnitudes (range) analyzed during APA and CPA intervals and over the duration of the whole task, represented by the COP area of sway and mean velocity. The CAI group exhibited a significant decrease in CPA and area of sway over the whole task, relative to controls. These results suggest that the decreased balance sway could be caused by the need for further stabilization of the ankle in more unstable postures to prevent recurrent sprain. Our findings could help clinicians to better understand the strategies of postural adjustments in individuals with CAI, and may assist and motivate new investigations into balance control interventions in such individuals, as well as proactively address recurrent ankle sprain conditions.
authors.affiliation: Department of Physical Therapy, Center of Health Sciences and Sport, Santa Catarina State University, Rua Pascoal Simoni 358, Florianopolis, SC 88080-350, Brazil; Department of Physical Therapy and Rehabilitation Sciences, School of Health Professions, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA. Electronic address: msantos@kumc.edu.
authors.forename: Marcio José
authors.initials: MJ
authors.lastname: dos Santos
authors.affiliation: Department of Physical Therapy, Center of Health Sciences and Sport, Santa Catarina State University, Rua Pascoal Simoni 358, Florianopolis, SC 88080-350, Brazil.
authors.forename: Ana Luiza
authors.initials: AL
authors.lastname: Gorges
authors.affiliation: Department of Physical Therapy, Center of Health Sciences and Sport, Santa Catarina State University, Rua Pascoal Simoni 358, Florianopolis, SC 88080-350, Brazil.
authors.forename: Jaqueline Lourdes
authors.initials: JL
authors.lastname: Rios
mesh_terms: D061725:Accelerometry; D000222:Adaptation, Physiological; D000328:Adult; D000465:Algorithms; D000704:Analysis of Variance; D000842:Ankle / Q000503:physiopathology*; D016512:Ankle Injuries / Q000150:complications / Q000503:physiopathology; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000209:etiology / Q000503:physiopathology*; D007866:Leg / Q000503:physiopathology; D008297:Male; D009068:Movement / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D012008:Recurrence; D055815:Young Adult
keywords: Ankle sprain; Anticipatory adjustment; Balance control; Functional ankle instability; Recurrent ankle sprain