It has to be considered that the presented results are valid only for the tested devices, but a transfer to other brace models is conditionally possible using the results of a study from Eils et al,6 which showed that different braces with a stirrup design had comparable results when tested within a shoe. It appears safe to assume that the stability loss of these braces for the cutout shoe condition is similar to the one tested in the present study. The results of the soft brace are not transferable to other soft braces because there are too many constructional and material differences between soft braces (eg, lace-up braces, special systems of straps, soft-material properties). However, the tested soft brace (leather material, lace-up design in combination with a system of straps) showed the highest amount of pas- sive stability for soft braces when evaluated in a compre- hensive test of 10 different ankle braces.6
To get a more comprehensive overview of passive stability characteristics of ankle braces in cutout shoe conditions, fur- ther investigations should evaluate several ankle braces to provide a basis of useful information to assist clinicians, ath- letic trainers, coaches, as well as consumers in choosing an appropriate brace model for individual requirements. It has to be considered that the actual results present the passive range of motion characteristics of external stability devices. Caution should be taken when recommending braces for applications under dynamic circumstances, but it was shown that similar stability characteristics occur with a less pronounced restriction under dynamic conditions.6
In the present investigation, passive range of motion characteristics of different ankle stabilizers were investi- gated to make recommendations for barefoot sports. There are different factors that may play a role in the prevention and rehabilitation of acute and recurrent ankle sprains. The restriction of motion might be one of these factors. It has to be considered that the effectiveness of external sup- port devices for prevention and rehabilitation might not solely be attributed to mechanical stability. Other factors such as an improved sensory input by the device might also play an important role. However, it has to be acknowl- edged that mechanical stability plays a role in the preven- tion of ankle sprains. Therefore, the results of the present investigation might be useful for the prevention and reha- bilitation of ankle injuries, although these recommenda- tions are based on mechanical evidence alone.
In conclusion, the passive stability characteristics of ankle braces depend to a great extent on being used in combina- tion with a shoe that provides an additional stabilizing effect. This is especially true for semirigid braces with a stir- rup design. Therefore, it is recommended that soft braces (like the one tested in the present investigation—leather material, lace-up design, in combination with a system of straps) should be used in barefoot sports to restrict passive range of motion, and this might have a positive effect on prevention and rehabilitation of ankle injuries in barefoot sports.