Sentence:  One of the most debated subjects in the whole of equestrianism is whether or not horses have bad backs. For some horsemen, a horse with a <WSD>'cold-back</WSD>' is merely demonstrating eccentric behaviour; for others, every unexpected response is indicative of a back problem. 
Meaning of the word marked with <WSD> tags:  A syndrome in which a horse refuses to accept anything on its back (often a symptom of chronic lower back soreness)