Final answer:
The direction of the heel lock when taping an ankle on the lateral side is from the front to under the heel and then upwards towards the back. This technique supports the lateral ankle ligaments and resists excessive inversion.
Step-by-step explanation:
When taping an ankle to prevent inversion, the direction of the heel lock on the lateral side of the ankle is from the front of the ankle, moving downwards and under the heel, and then upwards towards the back of the ankle. This technique is used to provide stability and support to the lateral ligaments of the ankle, particularly the anterior talofibular ligament, posterior talofibular ligament, and the calcaneofibular ligament.
Inversion ankle sprains frequently injure these lateral ligaments, and taping with a heel lock assists in minimizing the risk of injury by resisting excessive inversion movements. The tape should be applied in a way to mimic the support that the lateral ligaments provide, thus restricting the talus bone's lateral tilting and safeguarding against further injury.