Sport injuries are unwanted adverse effects accompanying participation in sports. In a wide variety of sports the most common location of injury is the ankle, frequently resulting from a forced plantar flexed inversion of the foot exceeding the physiological range of motion (ROM). Historically the purpose of external support systems is to prevent acute ankle injuries by restricting abnormal ankle ROM. It is believed that a superior restrictive effect also implies a superior preventive effect. The purpose of this review was to examine the literature regarding the restricting effect of adhesive taping, prophylactic ankle stabilisers (PAS) and high-top shoes on ankle ROM. It has been found that tape restricts ankle eversion and inversion ROM significantly following application. However, tape loosens significantly following standardised exercise and sports activities. Studies regarding PAS reported that both semi-rigid and nonrigid stabilisers give a significant post-application restriction of ankle inversion motion. The nonrigid stabilisers show loosening over time during exercise, while the semi-rigid stabilisers maintain their restrictive effect over the same time span. High-top shoes in comparison to low-top shoes are more effective in restricting mechanically imposed ankle inversion ROM. Low-top shoes, however, also limit mechanically imposed ankle inversion stress with the ankle in the position in which ankle injury occurs most frequently. One must keep in mind, however, that a superior mechanical restriction of ankle ROM does not necessarily imply a superior preventive effect. Only well-controlled randomised studies can show such an effect, and these studies have shown a reduction of ankle injury incidence for all 3 prophylactic measures reviewed.