Optimal duration of cold therapy applications at the ankle

Abstract

Relevance: This paper presents the results of a research study carried out with the intention to inform physiotherapists on the optimal duration of cold therapy at the ankle in order to maximise the impact on practice of decisions by physiotherapists for their patients/clients. Purpose: The major reason for doing this study was to determine the appropriate duration of ice applications to the ankle joint within the context of skin surface temperature in order to guide physiotherapists to make informed decisions on optimal duration. The aim of this study was to measure skin surface temperature changes at the ankle over a period of time and the objective to determine that point when no more significant skin surface temperature change was recorded. Methods/analysis: An experimental approach was followed to collect skin surface temperature data at the ankle joint, involving a control. Ice application was administered via two standardised methods: an ice bag containing 750 ml of ice cubes and 250 ml of water to 41 participants; and local immersion in a water bath kept between 16 and 18 °C (Lee and Warren, 1978) to 38 participants, who were all recruited through an open call for participation amongst university undergraduate students. The cold modality was applied to the participants’ right ankle for 30 minutes, during which skin surface temperature was recorded at 5-minute intervals using the FLIR i3® thermal imaging device. Concurrently temperature was recorded at the left ankle that served as a control. Skin surface temperature was recorded every 5 minutes and for a further 20 minutes following removal of the application. Repeated measures analyses of variance were applied to determine the significance of variation in temperature across time whilst pairwise comparisons were examined using post hoc Bonferroni tests. Results: Significant decreases in temperature were obtained for participants undergoing the ice bag (F = (10,31) = 661.04, p ≤ .001) and the local immersion (F = (10,28) = 217.36, p ≤ .001) techniques. Post hoc analyses revealed significant decreases in temperature using the ice bag application up to the 10 minute point but not after 15 minutes. Significant decreases in temperature were obtained for up to 15 minutes when using the local immersion technique. Discussion and conclusions: The findings suggest that there is no further significant drop in skin surface temperatures at the ankle following 15 minutes of ice bag application whilst at 10 minutes a significant change was still being recorded. These findings match the descriptive duration of application to bring about pain inhibition by Enwemeka et al. (2001). Also, no further significant drop in skin surface temperatures at the ankle following 20 minutes of local immersion application whilst at 15 minutes a significant change was still being recorded. Impact and implications: The optimal duration for the application of cold therapy to the ankle is between 10 and 15 minutes using the ice bag application and 15–20 minutes using the local immersion technique. These findings may guide the duration of application of cold therapy in practice settings.