In The Lancet today, Sarah Lamb and colleagues present a randomised trial in which they aimed to evaluate the effects of four different types of immobilisation devices (Tubigrip compression bandage, Bledsoe boot, Aircast brace, and below-knee cast) on the outcomes of patients recovering from severe ankle sprains. The investigators conclude that a below-knee cast for 10 days resulted in more rapid resolution of symptoms and pain and greatest recovery of self-reported ankle function at 3 months' follow-up compared with the other three treatments. This finding is likely to be viewed as controversial because consensus recommendations in recent decades have been towards functional treatment of ankle sprains. These recommendations emphasise little, if any, immobilisation, an early return to weight bearing, and progressive range of motion, balance, and coordination exercises.