Heart rate variability responses of horses and veterans with post-traumatic stress disorder to ground-based adaptive horsemanship lessons: a pilot study.
Abstract: Heart rate variability (HRV) can be measured as an indicator of autonomic nervous system (ANS) balance and thus, stress and affective arousal. Mixed results have been reported in the limited literature addressing the effects of equine-assisted services (EAS) on HRV in the human and horse participants. The aims of the present study were to determine the effects of ground-based adaptive horsemanship (AH) lessons on veterans' and horses' HRV during weekly lessons as well as veterans' resting HRV outside of lessons. Veterans with post-traumatic stress disorder (PTSD) were randomly assigned to 8 wk of AH or control (CON, no changes in treatments or activities) conditions. Horses were assigned to AH or control (CON, stall in arena) conditions based on previous experience (EAS or recreational riding). Electrocardiogram traces from the veteran and AH and CON horses were recorded during the 30-min lessons. Traces were recorded during resting conditions before (PRE) and after (POST) the 8-wk period from AH and CON veterans and healthy, non-veterans. Heart rate (HR), root mean square of successive differences (RMSSD) and low frequency to high frequency ratios (LF/HF) were calculated after identification of peaks with the Pan-Tompkins algorithm and manual correction during 5-min epochs. Data were analyzed with repeated measures, mixed model ANOVAs (SAS v9.4). HR was lowest ( ≤ 0.0323) in the horses and veterans during the first 10 min of the lessons. Veterans' RMSSD was higher (≤ 0.0496) in weeks 4 and 6 than week 2. LF/HF was greater in veterans with PTSD than healthy, non-veterans across PRE and POST time points. Increased HR later in the lessons is likely a result of increased movement in the horses and veterans. An interval of decreased stress and increased resiliency might be present in veterans participating in multi-day AH sessions. Increased sympathetic arousal measured via LF/HF was not mitigated by 8 wk of AH. Horses appeared unstressed by the interactions as no changes in HRV were observed.
© The Author(s) 2025. Published by Oxford University Press on behalf of the American Society of Animal Science.
Publication Date: 2025-02-12 PubMed ID: 40124971PubMed Central: PMC11926800DOI: 10.1093/tas/txaf019Google Scholar: Lookup
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Summary
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The study explored the impact of adaptive horsemanship programs on the heart rate variability of both horses and veterans suffering from post-traumatic stress disorder (PTSD), measuring stress levels and emotional arousal during and outside the weekly training sessions.
Study Overview
- The research explored the heart rate variability (HRV), an indicator of the balance of the autonomic nervous system (ANS), which reflects stress levels and emotional arousal. The study monitored both veterans with PTSD and horses during ground-based adaptive horsemanship (AH) lessons.
- The primary objective was to measure how these lessons affected the HRV of both parties during lessons, as well as the resting HRV of veterans outside of class.
Research Approach
- Veterans were randomly assigned to either an 8-week AH program or a control group with no change in treatments or activities.
- Horses were also separated into groups depending on their previous experience with either equine-assisted services (EAS) or recreational riding. They were assigned to either AH lessons or to control activities where they were in stalls within the arena.
Data Collection and Analysis
- Persons in the study and the horses involved had their electrocardiogram traces recorded during the 30-minute lessons, before and after the 8-week period.
- Specific variables and calculations such as heart rate (HR), root mean square of successive differences (RMSSD), and low frequency to high frequency ratios (LF/HF) were obtained using the Pan-Tompkins algorithm.
- The data was then analyzed using repeated measures and mixed-model ANOVAs.
Key Findings
- The lowest HR was observed in both horses and veterans during the first 10 minutes of the lessons.
- Veterans displayed a higher RMSSD during weeks 4 and 6 compared to week 2, implying that AH lessons might be associated with decreased stress and increased resilience for veterans with PTSD.
- Interestingly, an increased LF/HF ratio was found in veterans across pre and post time points, indicating that higher sympathetic arousal was not mitigated by the AH program.
- The horses involved in the study did not show any changes in HRV, which suggests that they were not stressed by their interactions with the veterans.
Cite This Article
APA
Rankins EM, Faremi BE, Hartmann K, Quinn A, Posada-Quintero HF, McKeever KH, Malinowski K.
(2025).
Heart rate variability responses of horses and veterans with post-traumatic stress disorder to ground-based adaptive horsemanship lessons: a pilot study.
Transl Anim Sci, 9, txaf019.
https://doi.org/10.1093/tas/txaf019 Publication
Researcher Affiliations
- Department of Animal Sciences, Equine Science Center, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA.
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA.
- Department of Animal Sciences, Equine Science Center, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA.
- Center for Psychological Services, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA.
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA.
- Department of Animal Sciences, Equine Science Center, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA.
- Department of Animal Sciences, Equine Science Center, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA.
Conflict of Interest Statement
The authors declare no conflicts of interest.
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