Forty recreational and professional athletes were followed in this prospective study comparing the acceptability and effectiveness of two orthotic component materials commonly used in sports medicine. TL-2100 SF (semiflexible) was compared to 4.0-mm thick polypropylene in six different subjective categories. The subjects were able to perceive a significant difference in favor of TL-2100 SF in the categories of weight, resilience and springiness, and overall comfort of the orthosis. The subjects were also able to perceive physical differences between these two component materials, which had previously been confirmed in laboratory studies.
A longitudinal single-blind study was conducted to test the friction blister prevention properties of synthetic acrylic socks in a generic construction. This study serves as a comparison with the authors' previous work comparing acrylic and cotton socks in a patented padded construction. Twenty-seven long-distance runners provided data regarding dampness, temperature, friction blister incidence, severity, and size. Two different socks were tested; each was identical in every aspect of construction except the fiber content. One test sock was composed of 100% synthetic acrylic fibers, and the other was composed of 100% natural cotton fibers. These results were unsuccessful at demonstrating any superiority of cotton or acrylic fibers when knitting produced a generic "cushion sole" sock. The superiority of acrylic fibers has thus far been demonstrated only when sock knitting provides adequate anatomical padding [corrected].
A longitudinal double-blind study was conducted to determine the effect of sock fiber composition on the frequency and size of blistering events in long-distance runners. Thirty-five long-distance runners participated in this study. Two different socks were tested, which were identical in every aspect of construction except fiber composition. One test sock was composed of 100% acrylic fibers, and the other test sock was composed of 100% natural cotton fibers. The results showed that acrylic fiber socks were associated with fewer blistering events and smaller blisters (mm2), when compared directly to cotton fiber socks.
Twelve human subjects were studied to determine the effect of three different floor surfaces on the medial shin musculature during stationary running. Electromyographic equipment, gated by an accelerometer affixed to the subject's shin, was used to separate the impact (eccentric) phase from the propulsive (concentric) phase of each running step. Excessive eccentric muscle activity has been associated with increased muscle damage, and recent investigations have linked medial tibial shin pain with actual structural damage to the muscle-fascial attachments to the posteromedial aspect of the tibia. Therefore, this study tends to verify the previous assumption that running on hard, noncompliant sport surfaces would predispose running and dancing athletes to shin muscle damage and resultant pain.