In dressage, the horse must always be ‘on the bit’, meaning that they are always in a collected frame and are accepting of the bridle with a consistent, submissive contact . Due to this, some riders use a crank noseband to clamp the horse’s mouth shut to prevent it from doing any behaviours such as licking and chewing which may be seen as being unsubmissive. The 2014 Fédération Equestre Internationale  dressage rules state that the noseband ‘may never be so tightly fixed that it causes harm to the horse and must be checked as per the Stewards Manual’ , which in turn claims that ‘The tightness check must be done with the steward’s index finger between the horse’s cheek and the noseband’ . However, despite these regulations in place, crank nosebands are still used in some competitions.
Recent evidence indicates that tight nosebands can cause a physiological stress response within the horse . A study conducted by Fenner and associates  tested this theory through analysing the horse’s oral behaviour, heart rate and heart rate variability, as well as eye temperature  which can be used as a correlation to salivary cortisol . They found that there was a significant shift in the horse’s heart rate, heart rate variability and eye temperature when the tight noseband was placed . They also found that while yawning, licking and chewing were mostly absent when wearing the noseband, it significantly increased in comparison to baseline frequencies following the removal of the noseband, suggesting a post-inhibitory response . This indicates that horses do experience a physiological stress response when the noseband is too tight, such as when wearing a crank noseband.
McGreevy and associates conducted a similar study and also found that there was an ‘increase of eye temperature when compared with baseline values’ . They also analysed the effects of a tight noseband on the facial skin of the horse and found that ‘the tighter the noseband was fastened, the cooler the facial skin of the horse (and, presumably, the greater impairment of vascular perfusion) when compared to baseline values’ .
Both of these studies indicate that crank nosebands and other forms of tight nosebands harms the horse’s wellbeing and causes a physiological stress response. Therefore, riders must become aware of the consequences of having their nosebands done up so tightly and also that the rules stated in the FEI dressage rulebook are enacted at all dressage competitions.
However, while a tight noseband may be something to consider for competition riders, what about the average rider? The pony clubber, the adult rider, the every-once-in-a-while rider who just loves to get on their horse and go for a ride. Is this something that they really need to consider? Of course this is important, if you can’t fit two fingers between the noseband and the horse’s nose, then, as mentioned above, this can cause serious problems and you should seriously consider loosening it a few holes. Nosebands have a function other than demonstrating submissive contact in a dressage test. They assist riders with their control over their horse and some evidence suggests a tightened noseband means that riders don’t need to use as much rein tension for deceleration. I would never suggest that riders should never use nosebands, however I do highly recommend that riders check the tightness of their nosebands before riding.
 FEI Stewards Manual, ed. 2009, Fédération Equestre Internationale
 FEI Dressage Manual, 25 ed., 2014, Fédération Equestre Internationale
 Fenner, K, Yoon, S, White, P, Starling, M & McGreevy, P 2016, ‘The effect of noseband tightening on horses’ behaviour, eye temperature, and cardiac responses’, PLoS one, vol. 11, no. 5, pp. 1 – 20
 McGreevy, P, Warren-Smith, A & Guisard, Y 2012, ‘The effect of double bridles and jaw-clamping crank nosebands on temperature of eyes and facial skin of horses’, Journal of Veterinary Behaviour, vol. 7, pp. 142 – 148
 McGreevy, P & Randle, H 2013, ‘The Effect of Noseband Tightness on Rein Tension in the Ridden Horse’, Journal of Veterinary Behaviour, vol. 8, pp. 18 – 19