Addressing Ankle Sprains
A sprained or ‘rolled’ ankle is a very common injury, with approximately 26,000 people experiencing this each day. As such, this is one of the most common injuries seen in the foot and ankle. A sprained ankle can happen to adults, children, athletes, and non-athletes. An ankle sprain can occur during sporting activities when walking on uneven surfaces or walking down the stairs.
Injuries to the ligaments of the ankle (usually the outside of the ankle) are known as ankle sprains.
Ligaments are elastic structures that attach bones to other bones. They function as stabilizers of joints as well as to prevent any excess movement of the bones to which they attach. Ligaments usually stretch within their normal limits and then return to their normal positions. When a ligament is stretched beyond its normal range, a sprain occurs. A severe sprain causes actual tears of the ligament fibers.
The ankle ligaments usually involved in an ankle sprain are also known as the lateral collateral ligaments of the ankle. The lateral collateral ligaments of the ankle are comprised of the anterior talofibular ligament, the calcaneofibular ligament, and the posterior talofibular ligament. Together, these three ligaments protect the ankle joint from abnormal movements – especially twisting, turning, and rolling of the ankle joint.
By their orientation, the lateral collateral ligaments provide stability to the ankle throughout the gait cycle as the foot bends up and down. Therefore total lateral stability of the ankle is provided by these three ligaments.
The most anterior (front) and most frequently injured of these ligaments is the anterior talofibular ligament. This ligament is intracapsular, or blended and contiguous with the lining of the anterior lateral aspect of the ankle joint capsule. It can be seen as a fibrous thickening of the lining of the joint and courses from the front of the fibula to the front of the lateral surface of the talus.
The main function of the anterior talofibular ligament is the prevention of axial or rotational instability of the ankle. During gait, as the heel is coming down, the foot is held in a dorsiflexed (up) position. Essentially the foot is pivoting on the edge of the heel only. Any irregularity in the ground, or laterally directed force, will cause the foot to twist in or out depending on the orientation of the force. Similarly, when we push off, the foot is in a plantar flexed (down) position. As the foot is plantar flexed, the position of the foot increases the long axis of the leg and increases the torque on the ankle region. Any ground irregularity or laterally directed force will cause the foot to twist in or out depending on the orientation of the force.