1. Simulating Riding Dynamics toward Developing a Kinematically-Realistic Mechanical Horse for Hippotherapy Research Rhett Rigby

2. What is Hippotherapy? “The use of a horse as a therapy instrument to treat patients with many different forms of neuromusculoskeletal disability” Main objective: to improve neurological function and sensory processing Used to treat: – Cerebral Palsy (CP) – Multiple Sclerosis (MS) – Down Syndrome – Developmental delays – Traumatic brain injuries – Spinal cord injuries

3. How Does Hippotherapy Work? Mechanics – Horse motion drives body through patterns it cannot perform itself – Motions mimic those of healthy human gait – Tunes joints, muscles, and neural pathways for these natural movement patterns Psychosocial influences – Emotional interaction with horse encourages patient and stimulates good mood

4. Purpose Until very recently, little research done to investigate the efficacy of hippotherapy To facilitate research and increase access to hippotherapy, Dr. Garner and I are planning the construction of a mechanical horse Purpose of this study was to compute the types of loads a mechanical horse needs to generate in order to simulate the realistic motion of a horse with a child rider

5. Methods Three-dimensional computer simulations were performed to model the dynamic interactions between a saddle and a rider A dynamic model that consisted of four rigid bodies was created – The saddle and lower torso of the rider – The rider’s abdomen – The rider’s upper torso, including the chest and arms – The rider’s head, including the neck, cranium, and helmet

6. Methods An inverse dynamics approach was used Inputs – Three translations and three rotations – Velocities and accelerations – Gravity – The mass and moments of inertia of each body Outputs – The active forces of the horse – The passive internal forces and moments experienced by the rider

7. Animation

8. Results

9. Discussion Model Significance – Fairly realistic model of a horse and rider dynamics – Results will guide construction of a mechanical horse – A mechanical horse will facilitate research and assist physical therapy Model limitations – Model only analyzes one period of a horse’s gait – Horse walks at different speeds – Horse may correct itself to prevent the rider from falling off

10. Future Studies Longer trial-run area More cameras need to be used to capture longer trial runs, both in time and distance More realistic inertial inputs to the model