%0 Journal Article
%T Effects of Cooling on Ankle Muscle Strength, Electromyography, and Gait Ground Reaction Forces
%A Amitava Halder
%A Chuansi Gao
%A Michael Miller
%J Journal of Sports Medicine
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/520124
%X The effects of cooling on neuromuscular function and performance during gait are not fully examined. The purpose of this study was to investigate the effects of local cooling for 20£¿min in cold water at 10¡ãC in a climate chamber also at 10¡ãC on maximal isometric force and electromyographic (EMG) activity of the lower leg muscles. Gait ground reaction forces (GRFs) were also assessed. Sixteen healthy university students participated in the within subject design experimental study. Isometric forces of the tibialis anterior (TA) and the gastrocnemius medialis (GM) were measured using a handheld dynamometer and the EMG was recorded using surface electrodes. Ground reaction forces during gait and the required coefficient of friction (RCOF) were recorded using a force plate. There was a significantly reduced isometric maximum force in the TA muscle ( ) after cooling. The mean EMG amplitude of GM muscle was increased after cooling ( ), indicating that fatigue was induced. We found no significant changes in the gait GRFs and RCOF on dry and level surface. These findings may indicate that local moderate cooling 20£¿min of 10¡ãC cold water, may influence maximal muscle performance without affecting activities at sub-maximal effort. 1. Introduction Temperature is considered to be significant determinant of skeletal muscle function and performance [1, 2]. Muscle force generation and power output vary with changes in body temperature. An optimal temperature range at which the best performance of muscle isometric contraction occurs has been described [3, 4]. It has also been demonstrated that muscle contraction forces and rate of force development were impaired at low muscle temperatures [5, 6] and voluntary muscular force production capabilities were reported to be affected below 27¡ãC without core temperature change [2]. In fact, Rutkove showed that even a low degree of cooling decreased the rate of muscular force production [7]. Various peripheral cooling protocols have been used to explore the effects on muscle performance. De Ruiter et al. [1] investigated the effect of temperature on the rate of isometric force development in the lower arm following 20£¿min immersion in water baths at 37¡ã, 31¡ã, 25¡ã, and 22¡ãC and found that isometric force was reduced below 25¡ãC. Cold water immersion of a limb causes a higher rate of heat loss compared to other environmental cooling. There are various sports and recreational activities both in water and land, where exposure to cold environments may affect power generation [3]. A recent study by C¨¨ et al. [8] showed that both fatigue
%U http://www.hindawi.com/journals/jsm/2014/520124/