Monday, October 6, 2008


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). Reports indicate that up to 73% of people who sustain a lateral ankle sprain have recurrent sprains, but it is unknown how many of these participants participate in rehabilitation. Proper immobilization and acute care of the injured ankle is imperative. Verhagen EA et al reviewed current data concerning the efficacy of preventive measures described in the literature, on the incidence of lateral ankle ligament injuries. They found overall, all studies reported a significant decrease in incidence of ankle sprains using the preventive measure.
Their findings ware as follows:
1. The use of either tape or braces reduces the incidence of ankle sprains. Next to this preventive effect, the use of tape or braces results in less severe ankle sprains. However, braces seem to be more effective in preventing ankle sprains than tape.
2. It is not clear which athletes are to benefit more from the use of preventive measures: those with or those without previous ankle sprains.
3. The efficacy of shoes in preventing ankle sprains is unclear. It is likely the newness of the footwear plays a more important role than shoe height in preventing ankle sprains.
4. Proprioceptive training reduces the incidence of ankle sprains in athletes with recurrent ankle sprains to the same level as subjects without any history of ankle sprains.

Arnold BL et al of Sports Medicine Research Laboratory, Department of Exercise Science, Virginia Commonwealth University, USA. Reviewed ankle taping & bracing titled “Bracing and rehabilitation--what's new”
Following are few points from their review:
1. Based on the recent evidence, ankle bracing and taping do appear to have positive effects on ankle support. For example, both bracing and taping restrict inversion range of motion, with tape and stirrup-style braces providing the best support. Although exercise reduces this restriction, the range remains consistent with levels considered to be within the normal range.
2. Ankle supports also appear to improve the strength of the muscular response to perturbation, potentially providing a stronger muscular contraction. In contrast, ankle supports fail to improve the neuromuscular response time to unexpected perturbations. Thus, it appears that the stronger response may occur too slowly to protect the joint. This slowness of the neuromuscular response, however, may be offset by the support's ability to slow the inversion motion. The slowing of inversion appears to allow the neuromuscular system to respond at or before the point of ligament damage. Finally, ankle supports appear to improve balance only in individuals with previously injured ankles. This suggests that supports may have a selective effect in protecting injured but not uninjured individuals.
3. Despite these positive effects, some cautions should be emphasized interpreting the above said results.
i. First, most of the studies cited have been performed in the laboratory setting with joint velocities and loads much below what are encountered in the athletic and daily activities. Whether tape and braces can maintain their effectiveness under the more extreme conditions of functional activities remains unclear.
ii. Additionally, some evidence suggests that ankle supports may transfer loads to other joints putting them at risk for injury. Thus, further study is needed to determine the risk-to-benefit ratio of ankle supports.
iii. Finally, much of the research presented has been done only on uninjured ankles.
Based on the current evidence, it seems possible that the effectiveness of ankle supports may differ depending on the population, and it seems clinically important to know whether we can expect the same results for injured and uninjured ankles.
4. Proper and early rehabilitation is important in preventing residual ankle symptoms. An immobilization boot or strapping that can be removed during early non-weight bearing exercises seems to be most effective.
5. Strength and balance training of the uninjured contralateral limb can be used to assist reaching full recovery in a shorter period of time.
6. Functional exercises can also be performed earlier in the rehabilitation process by reducing the gravitational forces so patients can perform in a pain-free range and still receive the benefits of early activity. Evidence shows that daily ankle disk (wobble board) training assists in preventing ankle sprains, and is a relatively inexpensive and easy alternative to traditional rehabilitation protocols.
How tape, braces and shoes affects ankle 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.
Verhagen EA et al reviewed the literature regarding the restricting effect of adhesive taping, prophylactic ankle stabilisers (PAS) and high-top shoes on ankle ROM. The findings are as follows:
1. 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.
2. 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.
3. 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.

Bottom line:
A superior mechanical restriction of ankle ROM does not necessarily imply a superior preventive effect.

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