The effect of immersion cryotherapy on medial-lateral postural sway variability in individuals with a lateral ankle sprain

Background and Purpose. Postural stability has been shown to be impaired after a lateral ankle sprain (LAS) and after immersion cryotherapy in healthy ankles. This study was performed to determine the effects of cryotherapy on postural stability after LAS. Method. A single-session, repeated measures design was used. Fifteen 18-to 29year- old males (mean age 21.33 +/- 3.54, height 71.23 +/- 2.50 cm, mass 170.33 +/- 19.77 kg) with relatively recent grade I LAS volunteered. Medial-lateral postural sway variability was assessed during single-leg barefoot stance using a Bertec force platform. Sway was tested before cryotherapy ('Pre'), immediately after 20 minutes of lower-leg immersion cryotherapy ('Post0'), and 10 and 20 minutes after cryotherapy ('Post10' and 'Post20'). Both legs were tested (individually) before cryotherapy; the involved leg was tested alone after cryotherapy. The uninvolved leg served as a control. Results. Postural sway variability of the involved le was signifi cantly greater than the uninvolved le before cryotherapy (p = 0.001). Postural sway variability of the involved le was also signifi cantly greater than the uninvolved LE during Post0 (p = 0.000), Post10 (p = 0.000) and Post20 testing (p = 0.003) with the largest increase in sway variability occurring at Post0. Conclusions. Mediallateral postural sway variability was greater after LAS. This effect was augmented by immersion cryotherapy. Copyright (C) 2008 John Wiley & Sons, Ltd.