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Strength Report - The Effects of Ankle Position on Change of Direction Movements on the Fieldby: Loren SeagraveSports Consultant © More from this issue Through our teachings of how athletes can reprogram their nervous systems to increase their speed and athleticism, the repositioning of the ankle joint has been the number two most important aspect for increasing acceleration and maximum velocity ability. The most important, joint reposition, is the change and control of the body position. The ankle must be dorsi-flexed immediately at take-off. In fact, Ralph Mouchbahani, while at the University of Freiberg, demonstrated that electrical activity could be observed during maximum velocity sprinting through EMG measurement over the anterior compartment of the lower leg prior to actual take-off. Anterior compartment muscles have responsibility for dorsi-flexing the ankle. There was a strong correlation in the timing for the anterior compartment activity and the speed of the sprinters. The better the sprinter, the sooner the electrical activity appeared. The ankle joint must be maintained in a dorsi-flexed position throughout the entire recovery and ground preparation phase and even held at touchdown so the foot and the ankle can be used as a springboard and breaking forces avoided. We now have observed the importance of repositioning the ankle joint on backward and lateral movement. This aspect not only has the potential for increasing performance, but also can reduce the likelihood of injury. The Fédération Internationale de Football Association (FIFA), the international governing body for the sport of soccer, commissioned a world-wide study of injuries in soccer. It revealed that the most common injury to players was ankle sprains and the third most common injury was knee sprains. Muscle strain was the second most common type of injury. In our North American brand of football, we would likely agree with FIFA’s findings. Especially disturbing are sprains of the ankles and knees that are not the result of contact. It has been our observation that many non-contact ankle and knee joint sprains or ligament tears are preceded by faulty positioning of the ankle joint. In the case of a knee ligament injury, notably the anterior cruciate ligament, mal-positioning of the ankle can often be accompanied by compromised stability of the hip joint. This allows excessive internal rotation which is not checked by the gluteus medius and lateral rotators. During deceleration in linear movement, plantar flexion (pointing the toes) is employed to slow the body down. This is, of course, the opposite of maintaining dorsi-flexion as was discussed earlier during acceleration and maximum velocity running precisely because premature plantar flexion results in breaking. We have observed several strategies used by athletes to decelerate, change direction and re-accelerate while moving laterally. The athlete will often place the foot flat on the ground during initial engagement with the ground (Photo 1). This results in a closed chain inversion position at the ankle joint. Even though the ankle joint exhibits excellent stability in a dorsi-flexed position, the inverted position at landing is less stable. This can result in an inversion sprain or the athlete will not execute a clean and abrupt deceleration or cut (change of direction) because the forces will exceed the joints capacity to stabilize and the athlete will “blow through the cut”. When the athlete is moving in the frontal plane (laterally) and wishes to decelerate abruptly, the plantar flexion movement at the ankle joint frequently enters into the motor pattern. The ankle joint is least stable when the ankle is plantar flexed and the forefoot is placed flat on the ground (Photo 2). The combination of an inverted foot placement with plantar flexion can often result in involving a greater number of ligaments. Film analysis during practice of professional defensive backs and linebackers who plantar flex prior to deceleration laterally also had a greater incidence of slips and falls compared to players who have employed the following strategy for lateral deceleration. The solution is to reprogram the athlete’s nervous system to engage the ground during lateral deceleration with a dorsi-flexed and everted ankle. This means that the sole of the foot is at a right angle with the long access of the tibia and the ground is engaged by the inside edge of the foot (Photo 3). In this way, the ankle is re-positioned to its most stable position, dorsi-flexed.
Maintaining a neutral position (bottom of the foot at a right angle to the long axis of the tibia) at the ankle joint by pretensing the everters* makes the muscles more ready (pre-activation) to aid in frontal plane stabilization. In addition, engaging the ground with the inside edge of the foot allows a small amount of time for the foot to flatten out (go slightly into inversion). In this amount of time, the mytotic (stretch) reflex can further engage more motor units to aid in ankle stabilization. * Interestingly, the ability to spontaneously evert the ankle with hip abduction is compromised with a history of sprained ankles. Loren Seagrave is Founder of Velocity Sports Performance |
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