Hans Tropp

Prevention of ankle sprains

Two different methods for the prevention of ankle joint injuries in soccer were tested. Coordination training on an ankle disk improves functional stabilty and postural control, whereas an orthosis provides mechanical sup port. Both techniques reduce the frequency of ankle sprains in soccer players with previous ankle problems. The orthosis is an alternative to taping, and can be used during the rehabilitation period after injury or when playing on uneven ground. Coordination training on an ankle disk ought to be included in the rehabilitation of ankle injuries to prevent functional instability. It may also be done prophylactically by players with previous ankle problems in order to break the vicious circle of recurrent sprains and feeling of giving way.

Stabilometry in functional instability of the ankle and its value in predicting injury

Stabilometry is an objective method used for studying postural equilibrium quantitatively. Stabilometric recordings were made in 127 soccer players to demonstrate functional instability of the ankle joint. The presence of previous ankle joint injuries, i.e., sprains or fractures, was documented. Reference values for stabilometry were obtained from a group of 30 normally-active non-soccer players without a history of injury to the ankle joint. A pathological stabilometric value was defined as one exceeding the mean value of the reference group by 2 SD. In players with a history of previous ankle joint injury no increased postural sway was found. On the other hand, players showing abnormal stabilometric values ran a significantly (P less than 0.001) higher risk of sustaining an ankle injury during the following season compared to players with normal values. Players with a history of previous ankle joint injury did not run a higher risk compared to players without previous injury. The findings indicate that an ankle joint injury did not result in a persistent functional instability; however, such instability did increase the risk of ankle joint injury.

The Incidence of Ankle Sprains in Soccer

This study investigated the relationship between exposure time and ankle sprains in soccer. Forty-one teams (639 players) from four male senior soccer divisions at different levels of skill (divisions I-VI) were followed prospectively for 1 year. The exposure to soccer and the number of injuries per player were higher in higher divisions, but the injury incidence, percentage of ankle injuries and incidence of ankle injuries were the same at different levels of skill. Of all injuries 17 to 20% were ankle sprains and the incidence varied between 1.7 to 2.0 ankle injuries per 1000 hours of exposure. Since players with previous ankle problems run an increased risk of reinjury we suggest that these players receive preventive advice.

Postural corrections after standardised perturbations of single limb stance: effect of training and orthotic devices in patients with ankle instability.

OBJECTIVE: Soccer players with functional instability of the ankle joint have shown impairment of postural control in single limb stance. The aim of this study was to examine the effect of stance perturbation. METHODS: A standardised method for the study of postural corrections after perturbation (Equitest) was used. Female soccer players with and without functional instability were examined. RESULTS: The subjects showed a relative change from ankle to hip synergy at medially directed translations of the support surface. This impairment was restored after eight weeks of ankle disk training. The effect of a shoe and brace did not exceed the effect of the shoe alone. CONCLUSIONS: Functional instability seems to be related to impaired ability to retain equilibrium in single limb stance by means of ankle corrections. A positive effect of ankle disk training leading to functional restoration was confirmed.

Altered movement and muscular-activation patterns during the one-legged jump in patients with an old anterior cruciate ligament rupture

We studied nine patients with an isolated, unrepaired rupture of the anterior cruciate ligament to evaluate whether well-rehabilitated patients with an old rupture of the anterior cruciate ligament had adapted their patterns of motor control in situations that provoke knee instability and if the possible adaptation results in a measurable decrease of the deteriorating sagittal shear load. The study was performed by means of a movement analysis system with synchronized force plate and electromyographic recordings. A different movement and muscular-activation pattern was found for the injured leg compared to the noninjured when performing a one-legged jump for distance. An internal knee model was developed and implemented. In that way, a simultaneously decreased capsuloligamentous sagittal load at the landing moment was shown.

Ankle Performance after Ankle Fracture: A Randomized Study of Early Mobilization

In a prospective, randomized study, 30 patients were evaluated after ankle fracture treated by means of open reduction and internal fixation. The patients were randomized to either postoperative immobilization in a plaster cast for 6 weeks or early mobilization (1–2 weeks after surgery) in an ankle brace. Both regimens allowed weightbearing. Evaluation after 10 weeks and after 12 months included clinical assessment and isokinetic muscle strength measurements. Patients with impaired ankle function, as shown by means of an ankle score at 12 months, were followed for 3 years. At 10 weeks, impaired muscle torque and restricted range of motion was found on the affected side. This impairment was significantly less in the brace group. At 12 months, range of motion of the ankle and subtalar joints was restored, but dorsiflexion was still better in the brace group. Score values from a functional score did not correlate with muscle strength.

Effects of ankle disc training on muscular strength and postural control.

Ankle disc training gave good objective results in patients with functional instability of the ankle joint, that is a feeling of giving way or recurrent sprains. The training programme improved both postural control, as demonstrated by stabilometry, and isokinetic pronator muscle strength. A 10-week training period was apparently sufficient, and further training could not be shown to be beneficial.