Comparison between natural rubber knee support and sponge knee support on the protection of knee joint: A crossover randomized controlled study among patients with bleeding disorders

Abstract Background and Aims Knee support, frequently made from sponge, is used to reduce injury. Sponge has less elasticity and durability compared with natural rubber. To our knowledge, there was no study that demonstrated the effectiveness of natural rubber and sponge in prevention of injury in children with bleeding disorders. The study aimed to demonstrate the effectiveness and satisfaction of natural rubber knee support compared with sponge knee support among children with bleeding disorders. Methods The study consisted of three phases: (I) measuring reduced compression force, (II) producing size‐appropriate knee support prototypes, and (III) conducting a randomized crossover trial, including 8 weeks wearing natural rubber knee support and sponge knee support with a 4‐week wash‐out period. The number of knee bleeds and user satisfaction were recorded. Results A better compression force reduction in natural rubber (60%) than sponge (12%) was demonstrated. Knee support comprised a body part, made from natural‐stretchable cotton and a protection part, made from either natural rubber or sponge. They were produced in four sizes: S, M, L, and XL and appropriately applied to 42 patients (21 hemophilia, 21 platelet disorders) with a mean (SD) age of 7.0 (2.9) years. The results from randomization showed no significant difference in the number of knee bleeds between the two knee support groups (10 vs. 7, p = 0.37). In terms of satisfaction score, the natural rubber knee supports were more durable (45.2% vs. 23.8%, p = 0.04) and easier to use (28.5% vs. 14.3%, p = 0.03). In addition, a higher percentage of parents chose natural rubber knee support when compared with sponge knee supports (71.0% vs. 29.0%, p = 0.006). Conclusion Natural rubber knee support showed comparable effectiveness in the prevention of knee bleeding but was superior to sponge knee support in compression force reduction and satisfaction.