An investigation into the skin surface temperatures using ice bag application and local immersion techniques at the ankle

Abstract

Relevance: This paper presents the results from a research study carried out with the intention to maximise the impact on practice, by providing evidence of skin surface temperature changes when applying two different cold therapy modalities, for physiotherapists to make an informed decision within the clinical scenario. Purpose: The major reason for doing this study was to compare the skin surface temperature changes between the application of an ice bag and local immersion. The aim was to identify which modality resulted in a faster drop in temperature and therefore the objective was to determine the more optimal application of cold therapy between these two modalities. 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 et al., 1978) to 38 participants, who were all recruited through an open call for participation amongst university undergraduate students. The cold therapy 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 for a further 20 minutes following removal of the application. Data was analysed using the independent samples t-test. Levene's test was used to observe for differences in the variances concerned with the distribution around the mean. Results: Significant differences in temperature were recorded at 5 minutes (t(51) = −15.456, P = <0.001) up until removal at the 30 minutes (t(60) = −30.476, P = <0.001), with mean skin surface temperature for the ice bag group being 7.3 °C compared to 18.1 °C for the local immersion group. A significant difference was also observed 20-minute following removal (t(50) = −2.108, P = 0.04) with mean temperatures of 21.9 °C and 23.3 °C respectively but rewarming following the ice bag application was faster. Discussion and conclusions: The findings suggest that the ice bag application was more efficient in reducing skin surface temperature reaching the therapeutic temperature range of 10 to 15 °C as described by MacAuley (2001). Following application of the ice bag technique skin temperatures returned at a faster rate, implying that the therapeutic effects were short-lived, in line with the findings of Myrer et al. (2001). Impact and implications: The ice bag application reduced skin surface temperature to within therapeutic ranges (Kennet et al., 2007) unlike the local immersion technique; however the benefits were short-lived. This provides an opportunity for further research.