The effects of ice water and room temperature water immersion on postural control and sensorimotor performance in amateur rugby players

Abstract

Rugby is one of the most popular contact sports worldwide and has received much scientific attention. Emphasis has been placed on the injury profiles of rugby players, but their physiological profile, such as postural control (i.e., balance), has been underexamined. Two exploratory cross-sectional studies were performed to compare the standing balance performances of amateur rugby players and nonplayers. The results show that rugby players had inferior static standing balance performance (P < 0.001), suboptimal sensory organization of balance control (P = 0.005), and prolonged reactive motor response time (P < 0.001) compared with nonplayers. Specifically, rugby players relied less on their vestibular (P = 0.005) and visual inputs (P = 0.005) for postural control and over-relied on a hip strategy to balance (P < 0.001; Studies 1 and 2). Further analysis revealed that rugby players’ inferior balance strategy was associated with insufficient training experience (P = 0.006) but not with their history of injury (Study 2). Ice water immersion (IWI) is commonly used as a recovery strategy after rugby training and competitions to reduce body temperature. However, exposure to extremely low temperatures may physiologically compromise neuromuscular systems. It is possible that IWI further compromises the suboptimal balance performance of less-experienced amateur rugby players and that an alternative method – room-temperature water immersion (RWI) – might serve the same purpose. The aim of the second part of the research was to investigate and compare the effects of postexercise IWI and RWI on sensorimotor, balance, and functional performance in amateur rugby players. A randomized controlled trial was performed to compare the effects of postexercise IWI (5°C; 13 participants), RWI (25°C; 18 participants), and no water immersion (22 participants) on standing balance performance, knee joint proprioception (Study 3), leg muscular strength, vertical jump, and agility (Study 4) in amateur rugby players. Fifty-three rugby players (mean age, 21.6 years) were randomly assigned to the IWI group, the RWI group, or the no-immersion control group. After a bout of fatiguing exercise, the participants underwent an immersion intervention. All outcomes were measured at baseline and after intervention. The results reveal that neither IWI nor RWI altered the sensory organization of balance control or agility performance (P > 0.05). IWI was shown to impair knee joint proprioception (P = 0.022), knee extensor peak force (P = 0.031), and jump performance (P = 0.030); whereas RWI helped the rugby players’ knee flexor muscles to reach their peak force more quickly (P < 0.001). These findings demonstrate the feasibility and advantages of RWI, a relatively comfortable recovery strategy, in place of IWI for training recovery after rugby.