Soccer is one of the most popular sports throughout the
world, with more than 250 million players in 2000.9 It has
a high injury rate, and most injuries occur to the lower
extremities, especially the ankle.31 Ankle inversion sprains
are the most common injuries in soccer7 and occur during
plantar flexion and inversion of the foot.29 Athletes who
suffer from ankle sprains are most likely to reinjure the
same ankle.6 The high incidence of ankle sprains in sports
and their negative consequence for further sports participation
call for preventive measures.
Proprioception refers to the inborn kinesthetic awareness
of body posture including movement. Proprioceptive
training is a crucial part of preventing ankle injury.15 It
usually includes exercises on devices such as balance
boards, ankle disks, and tilt boards, several times a week.
Sheth et al21 hypothesized that an ankle disk training program
would markedly decrease the time for onset of activation
of ankle muscles.21 Those authors believed that
ankle disk training is a unique method because it stimulates
multiple planes of ankle movement on a weightbearing
foot. Tropp et al27 reported a decreased rate of ankle
sprains in soccer players after an ankle disk training program
of 10 weeks. There is not much dispute about the
actual benefits of such a program, but there are questions
about how much it helps and the specific stimulation it
generates.8
The evertor muscles are often suggested to play an
important role in preventing ligamentous injuries. Tropp
et al28 were the first to measure muscle torque at the ankle
with an isokinetic dynamometer. Their results showed that evertor muscle weakness is a component of recurrent
ankle sprain. Willens et al30 postulated that eccentric contraction
of these muscles provides support to lateral ligaments
and resists ankle inversion sprains. So strength
training of evertor muscles is another part of preventing
ankle sprains.
External support (with orthoses or taping) is widely
used to prevent ankle sprains among athletes, and many
studies have been done to establish its effectiveness. Sitler
et al22 reported that orthoses reduced the incidence of
ankle sprains in previously sprained ankles. Surve et al25
and Doxey5 postulated that the main effect of orthoses is to
improve the proprioceptive function of a previously injured
ankle. Thonnard et al26 reported that orthoses protect the
ankle by preventing inversion movement and maintaining
the ankle in proper anatomical position at impact.
Additional research is needed to determine the exact
mechanisms underlying the effectiveness of orthoses.
I am not aware of any previous research that has compared
these 3 interventions (proprioceptive training,
strength training, and orthoses) in soccer players with previous
ankle inversion sprains. Therefore, I conducted a
randomized controlled trial study examining ankle sprain
recurrences in athletes using different types of preventive
strategies compared with a control group.