You SH; Department of Physical Therapy, Hampton University, Hampton, VA, Granata KP; Department of Orthopaedic Surgery & Biomedical Engineering, University of Virginia, Bunker LK; Department of Kinesiology, University of Virginia, Charlottesville, VA. Sung.you@hamptonu.edu.

PURPOSE: To determine the effect of circumferential ankle pressure (CAP) intervention on passive ankle stiffness (PAS) and active ankle stiffness (AAS) during bilateral stance in individuals with chronic ankle instability (CAI) and healthy individuals. DESIGN: Randomized control study with pre- and post-tests. SETTING: University research laboratory. SUBJECTS: 4 healthy subjects and 5 subjects with CAI. Based on the entering proprioceptive acuity (EPA) scores, the subjects were assigned to either the lower entering proprioceptive acuity (LEPA) group or the higher entering proprioceptive acuity (HEPA) group. METHODS AND MATERIALS: Blindfolded subjects were asked to maintain symmetrical weight bearing stance with the ankle in a neutral position. PAS and AAS were measured before and after application of CAP using a 60-mm Hg pressure cuff placed around the ankle without restricting ankle motion. PAS was computed from the ratio of applied static moments (zero, 6.13Nm, and 9.19Nm) and angular displacements in all the planes of ankle motion. The McNair method for computing transient-harmonic motion following medial-rotational perturbation induced by three separate levels of applied external inertia (zero, 0.07kgm², 0.14kgm²) was used to determine AAS. The frequency of oscillation following the perturbation was calculated: I_{Ext =} K_A/ω_n² – I_Ankle. ANALYSES: Repeated measures of analysis of variance (ANOVA) and Tukey test. RESULTS: Repeated measures of analysis of variance (ANOVA) revealed no significant differences in PAS, but significant differences in AAS between groups during application of CAP (p < .10). CONCLUSIONS: CAP effected increased AAS in individuals with LEPA. FUNDING SOURCE: None.

Reprint Information
Requests for reprints should be directed to the corresponding author of the article. Students and other academic customers may receive permission to reprint copyrighted material from Physical Therapy by contacting the Copyright Clearance Center Inc, 222 Rosewood Dr, Danvers, MA 01923. Similar inquiries by all others should be made to the APTA Editorial Office, Attn: Physical Therapy.