A systematic literature review to evaluate the tools and methods used to measure rein tension.

The use of pressure via a bit in the horse’s mouth is part of training methods throughout equine disciplines. Rein tension refers to the force exerted on the reins between the horse and human during ridden and in-hand training. Understanding the effects of these forces has the potential to inform both rider performance and equine welfare research. The methodological protocols of current rein tension research appear inconsistent and to date, a review on rein tension has not been published. This study uses a systematic literature review to evaluate the tools and methods used to measure rein tension within current literature to establish whether their findings were reliable. The review also suggests improvements to study protocols, where appropriate, to enable the standardised measurement of rein tension. A search protocol was developed and inclusion criteria defined with the aid of independent subject specialists, including two published equestrian authors, an equine industry professional and a librarian. Inclusion criteria determined that only full peer reviewed articles available via Google Scholar, and published in the previous fifteen years were included in the review. Articles also had to include the following key words: rein tension AND ‘horse/s’ OR ‘rider/s’ OR ‘equine/s’ OR ‘equestrian’. The literature search returned 154 initial results and the inclusion criteria rejected 137 results. Seventeen primary research articles (post 2002) from peer-reviewed journals were subsequently reviewed. The articles reviewed found rein tension to be influenced by the horse, the rider and the training equipment used. Rein tension studies have multivariable foci, methodological limitations and frequently report their methods and results inconsistently. Future rein tension research should aim to improve the consistency of reporting horse-related, rider-related and performance-related factors that may affect rein tension, as well as reporting data handling and analysis approaches in order to increase comparability between studies.