Muscle reaction function of individuals with intellectual disabilities may be improved through therapeutic use of a horse Paraskevi Giagazoglou *, Fotini Arabatzi, Eleftherios Kellis, Maria Liga, Chrisanthi Karra, Ioannis Amiridis Laboratory of Neuromechanics, Department of Physical Education and Sports Science, Serres, Aristotle University of Thessaloniki, Greece 1. Introduction Individuals with intellectual disabilities (ID) are characterized by a lower ability to understand new or complex information and to learn and apply new cognitive, social and motor skills. Successful performance of motor skills is dependent on the individual’s ability to establish and maintain stability throughout a sequence of controlled movements (Smail & Horvat, 2005). A common characteristic observed during voluntary movements among individuals with ID is that they need more time to initiate and respond to movements (Latash, 2000). Reaction time is an index of sensori-motor performance in sports (Nakamoto & Mori, 2008) and reflects the time between application of a stimulus (e.g., sound or flash of light) and response to the stimulus (Welford, 1980). The shorter the reaction time people have, the sooner they will be able to react to the actions around them. Thus, in the case of an unexpected sudden situation or danger they will protect themselves in a very short time. Research in Developmental Disabilities 34 (2013) 2442–2448 ARTICLE INFO Article history: Received 17 February 2013 Received in revised form 19 April 2013 Accepted 22 April 2013 Available online Keywords: Reaction time Muscle activation Adapted physical training Hippotherapy Mental retardation EMG ABSTRACT Reaction time and muscle activation deficits might limit the individual’s autonomy in activities of daily living and in participating in recreational activities. The aim of the present study was to assess the effects of a 14-week hippotherapy exercise program on movement reaction time and muscle activation in adolescents with intellectual disability (ID). Nineteen adolescents with moderate ID were assigned either to an experimental group (n = 10) or a control group (n = 9). The experimental group attended a hippotherapy exercise program, consisting of two 30-min sessions per week for 14 weeks. Reaction time, time of maximum muscle activity and electromyographic activity (EMG) of rectus femoris and biceps femoris when standing up from a chair under three conditions: in response to audio, visual and audio with closed eyes stimuli were measured. Analysis of variance designs showed that hippotherapy intervention program resulted in significant improvements in reaction time and a reduction in time to maximum muscle activity of the intervention group comparing to the control group in all 3 three conditions that were examined (p < 0.05). The present findings suggest that the muscle reaction function of individuals with ID can be improved through hippotherapy training. Hippotherapy probably creates a changing environment with a variety of stimuli that enhance deep proprioception as well as other sensory inputs. In conclusion, this study provides evidence that hippotherapy can improve functional task performance by enhancing reaction time. ß 2013 Elsevier Ltd. All rights reserved. * Corresponding author at: 58, Irodotou Street, 62125 Serres, Greece. Tel.: +30 2310 991066. E-mail address: pgiagaz@phed-sr.auth.gr (P. Giagazoglou). Contents lists available at SciVerse ScienceDirect Research in Developmental Disabilities 0891-4222/$ – see front matter ß 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ridd.2013.04.015