The study of neuromuscular responses during landing is an important aspect to address in development of preventive and training strategies especially in water environment. The purpose of this study was to compare neuromuscular responses of lower extremity muscles during various jump-landing tasks in water and on land in active young females. Nine healthy active women volunteered to participate in the investigation. The onset of muscle activation prior to initial contact and maximum RMS over 150 ms prelanding and 150 ms post landing for vastus lateralis (VL), medial hamstring (MH), lateral hamstring (LH) and lateral gastrocnemius (LG), in Drop-landing (DL), Drop-Jump (DJ) and countermovement jump (CJ) tasks were calculated and then normalized to the peak RMS amplitude of MVIC and reported as percentage. Dependent t-test was used to analyze the effect of environment on each dependent variable. The normalized EMG value for VL before landing was significantly lower for CJ (p=0.000), DL (P=0.01) and DJ (P=0.001). Similar to the VL, for lateral gastrocnemius the normalized EMG before landing was significantly lower in CJ (p=0.000). With the exception of CJ (P=0.000), there was no significant difference in pre activation of hamstrings between land and water environment. VL had significantly lower normalized EMG value in water than on land in CJ (p=0.04), DL (p=0.000) and DJ (p=0.012). With respect to the different muscle activity in water compared in land, prescription of aquatic jump-landing exercises in order to conditioning should be considered.

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