The effect of therapeutic horseback riding on heart rate variability of children with disabilities.

Abstract

Introduction: Heart rate variability (HRV) is the oscillation in the interval between consecutive heart beats, resulting from dynamic interplay between multiple physiologic mechanisms that regulate instantaneous heart rate. Short-term heart rate regulation is governed by sympathetic and parasympathetic neural activity and therefore HRV examination can be used as a non-invasive estimate of the functioning of the autonomic nervous system (ANS). Aim: To determine the effects of therapeutic horseback riding (THR) intervention on the HRV of children with disabilities including autism spectrum disorder, cerebral palsy, pervasive developmental disorder, sensory problems, and Down syndrome. The objective was to examine if THR intervention improves the HRV of children, hence improving the parasympathetic activity that is associated with a calm and relaxed state. Methods: This is a quasi-experimental design. Heart rate variability components (time and frequency domain) were measured over six intervention group sessions of THR which were conducted once a week for six weeks. The duration of the THR sessions was 20-25 minutes for each group. The THR sessions included riding, mounting and dismounting, trotting, as well as performing activities such as extending arms and throwing a ball while on a horse. Heart rate variability measures were recorded from 29 participants presenting with various disabilities, and was assessed in both time and frequency domains. Results: Over the six THR sessions, the time domain component (RR interval) showed a significant increase in HRV for pre-THR from session one to session six (p=0.011), indicating improved vagal activation. However, frequency domain showed both increased sympathetic activity from session one to session six (p=0.022) reflected by component coefficient of variance for low frequency (CCV LF) and increased parasympathetic activation during THR from session four to session six (p=0.045), reflected by total power (TP). Conclusion: Therapeutic horseback riding intervention of six sessions demonstrated a change in HRV of children with disabilities. However, the changes obtained were not significant to make conclusive measures as to whether sympathetic or parasympathetic activity is predominantly increased after the six sessions. Further research involving a larger sample with a single type of a disability would be recommended to improve the reliability and validity of the study. Furthermore, having a control group would improve the reliability of the study.