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Synopsis: Long-term ankle bracing does not affect peroneus longus muscle latency during sudden inversion.
Source: Cordova ML, et al. Long-term ankle brace use does not affect peroneus longus muscle latency during sudden inversion in normal subjects. Journal of Athletic Training 2000;35(4):407-411.
Competitive and recreationally physically active people commonly use prophylactic ankle bracing. Cordova and colleagues sought to determine if long-term ankle bracing had a deleterious effect on per- oneus longus muscle latency, and if bracing affected latency before a period of extended use. Subjects were 20 physically active, college-aged individuals free from history of ankle injury for 12 months prior to the study. Subjects were randomly assigned to wear the Active Ankle Training brace, McDavid 199 brace, or no brace for eight hours a day, five days a week for an eight-week period. Prior to group assignment, subjects were tested for peroneus longus muscle latency under all three conditions in counterbalanced order. Electrical activity of the peroneus longus muscle was measured during a sudden and randomly applied inversion movement on a custom-made inversion platform. Subjects assumed a double-leg stance with weight evenly distributed on the platform. Muscle latency was defined as the time between the initiation of the inversion movement and the first electrical activity of the peroneus longus muscle. The muscle latency testing procedures were repeated following the eight-week treatment period.
Analysis of variance found no differences in latency between the three test conditions (Active Ankle, McDavid, and no-brace), and no changes in latency were observed after the eight-week period of brace wearing. The range of latency values under all conditions was 41.0-56.0 ms, which is consistent with the spinal reflex.
Many clinicians theorize that prolonged wearing of braces increases dependence on the external support. Cordova et al used a creative research design to test this unsubstantiated concern of many physicians and clinicians. Cordova et al hypothesized that if the bracing had a deleterious effect, it would be manifested through a neuromuscular remodeling of the peroneus longus muscle. The consequence of this remodeling would be an increase in latency with a sudden inversion. They did not find this to be the case.
Prophylactic ankle taping for competitive athletes is the practice of many certified athletic trainers. Some have a similar concern that the application of tape over the course of a season can increase an athlete’s dependence on the support. Although the design of this study did not incorporate ankle taping, it seems unlikely that the application of tape for a period of just several hours each day would have deleterious effects on the neuromuscular system.
It would be interesting to test the same hypothesis of this study in subjects recovering from acute ankle sprain or suffering from chronic functional ankle instability. It is possible that a neuromuscular system that has been traumatized by excessive inversion with damage to associated structures might respond differently to the prolonged application of bracing.
The failure to find any effect of the bracing on latency of the peroneus longus muscle during pretesting suggests the value of prophylactic ankle bracing in healthy people may be questionable. The debate over the role of preventive ankle sprain bracing continues. Some contend the benefit is earlier feedback from the sensorimotor system during forced inversion, while others feel the brace provides a mechanical block to excessive inversion. The role of mechanical blockage is unclear, and this study would not seem to support the proprioceptive feedback model. Perhaps the amount of inversion was insufficient to activate a protective response from the wearing of braces. Further research is warranted to address the value of ankle orthoses in the prevention and rehabilitation of ankle injuries.
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