Hyperflexing the horse's neck: a systematic review and meta-analysis.

Area of Science:

• Equine welfare science
• Animal biomechanics
• Veterinary sports medicine

Background:

• Dorsoventral hyperflexion of the neck in horses, known as hyperflexed head and neck posture (HNP), has been a subject of significant public and scientific debate for 20 years.
• Concerns exist regarding the ethical implications and physiological effects of this training method on equine athletes.

Purpose of the Study:

• To conduct a meta-analysis of existing peer-reviewed literature to establish a consensus on the welfare and performance outcomes of horses in HNP.
• To evaluate the scientific evidence regarding the impact of HNP on equine welfare and athletic performance.

Main Methods:

• A systematic meta-analysis of 58 peer-reviewed studies was performed.
• Databases searched included CAB, Google Scholar, Web of Science, NAL/Agricola, PubMed, and ScienceDirect (last search 28.05.2023).
• Statistical analyses were used to synthesize conclusions on welfare and performance (marks, kinematics, musculoskeletal) outcomes.

Main Results:

• A significant majority of studies (75%) expressed concerns about horse welfare when in HNP.
• Factors like training level, experience, or duration did not significantly alter welfare concerns.
• Performance outcomes were inconclusive, with benefits, detrimental effects, and no significant effects reported across studies.

Conclusions:

• The practice of HNP appears to impair equine welfare irrespective of the method used to achieve the posture.
• The potential welfare costs associated with HNP likely exceed any demonstrated performance benefits.
• Further research and ethical considerations are warranted regarding the widespread use of HNP in equine disciplines.