The human-horse interaction in the context of equine assisted activities
Creators: name: Rankins, Ellen Marie
Publisher: name: No Publisher Supplied
Year: 2023

description: Equine assisted services is an umbrella term for adaptive horsemanship, therapies incorporating horses, and equine assisted learning which all incorporate horses to benefit humans. One population for which these types of services have become popular is veterans with post-traumatic stress disorder (PTSD). Despite this popularity, relatively little research has been undertaken on the effects of these interventions on the horses and humans involved. The aims of this dissertation were to 1) characterize and describe the literature on equids in equine assisted services; 2) explore the use of muscular tension measured via surface EMG as an indicator of horse stress; 3) determine if differences in basal plasma hormone concentrations and social motor synchrony exist in combat veterans with PTSD and combat veterans without PTSD and 4) determine the effects of equine assisted activities on veterans with PTSD and horses while describing components of the human-horse interaction. For the first aim, a systematic literature search and scoping review were conducted. Studies investigating equids in equine assisted services have primarily focused on characterizing equids in equine assisted services, investigating the acute responses of equids to equine assisted services, investigating the effects of management strategies on equids in equine assisted services, and investigating the chronic effects of equine assisted services on equids. A pilot study using measurement of physiological and behavioral markers of stress in horses alongside surface electromyography (sEMG) during three conditions known to elicit stress in horses (sham clipping, novel object exposure, and social isolation) were used to evaluate the potential use of muscle tension as an indicator of acute stress. Increases in muscle activity were found during sham clipping. Challenges remain in the use of muscle tension as an indicator of acute stress in horses, primarily in the normalization of EMG data. No differences were found in basal plasma cortisol, epinephrine, norepinephrine, and oxytocin concentrations in veterans with PTSD as compared to veterans without PTSD. Greater synchrony was found in veterans with PTSD than veterans without PTSD during one of the unintentional synchrony trials, but no differences in intentional synchrony were found. Symptoms of PTSD decreased in veterans following eight weeks of equine assisted activities (EAA) and these same changes were not found in veterans in the wait-listed control group. Horses participating in EAA with the veterans experienced little to no stress as they had lower cortisol concentrations and stress-related behaviors than horses in the control condition (confined to a stall within the arena concurrent with the EAA session). Scores for human-horse interaction increased during the study and a significant co-regulation coefficient between horse and human was found in week 8 for epinephrine. Future research should continue to focus on the human-horse interaction and its relation to human and horse responses and outcomes in equine assisted services. Development and validation of tools and measurements, particularly those that can capture positive affective states and interactions, are needed.