An ankle sprain occurs when ligaments, the strong tissues supporting the ankle joint, are stretched or torn. While many people are familiar with ankle sprains, a less common type is the eversion ankle sprain. This injury involves the ligaments on the inner side of the ankle.
Ankle Anatomy and Ligaments
The ankle joint is formed by the interaction of three bones: the tibia (shin bone), the fibula (smaller lower leg bone), and the talus (a bone in the foot). These bones are held together by a network of ligaments that provide stability. On the inner side of the ankle, a collection of strong ligaments forms what is collectively known as the deltoid ligament.
The deltoid ligament is a broad, fan-shaped structure with both superficial and deep components. It originates from the medial malleolus, which is the bony protrusion on the inside of the ankle, and fans out to connect to several bones in the foot, including the talus, calcaneus (heel bone), and navicular bone. These strong fibers help stabilize the ankle and restrict excessive outward movement of the foot.
How Eversion Sprains Occur
An eversion ankle sprain happens when the foot is forced outwards, a movement called eversion, while the ankle rolls inward. This motion puts significant stress on the deltoid ligament on the inner side of the ankle, causing it to stretch or tear. This can occur in various situations, such as landing awkwardly after a jump, stepping on an uneven surface, or experiencing a direct blow to the outside of the ankle.
Recognizing an Eversion Sprain
Recognizing an eversion sprain involves specific signs and symptoms centered on the inner side of the ankle. Individuals experience immediate pain directly over the deltoid ligament. Swelling and bruising often develop in the affected area. Tenderness to the touch over the inner ankle bone is common. Moving the foot, especially turning it outwards, can intensify the pain, potentially causing difficulty bearing weight.
Why Eversion Sprains Are Less Common
Eversion ankle sprains occur less frequently than inversion sprains, which affect the outer ankle ligaments. This difference is due to the ankle joint’s anatomical design. The deltoid ligament, on the inner side, is stronger and broader than outer ankle ligaments.
The ankle’s bony structure also provides protection against eversion movements. The lateral malleolus, the prominent bone on the outside, extends lower than the medial malleolus on the inside. This longer lateral bone acts as a protective barrier, limiting outward foot turning and reducing strain on the deltoid ligament. The robust deltoid ligament and bony anatomy contribute to the reduced incidence of eversion sprains.
Immediate Actions Post-Injury
Following a suspected eversion ankle sprain, immediate action can help manage symptoms and promote healing. Applying the RICE principle—Rest, Ice, Compression, and Elevation—is a common first aid approach. Resting the injured ankle by avoiding activities that cause pain helps prevent further damage.
Applying ice to the inner ankle for 15-20 minutes every two to three hours can help reduce swelling and pain. Compressing the ankle with an elastic bandage can also help control swelling, ensuring it is snug but not too tight to affect circulation. Elevating the injured ankle above heart level assists gravity in reducing fluid accumulation. It is important to seek prompt medical evaluation, especially if there is severe pain, significant swelling, or an inability to bear weight, as a healthcare professional can rule out more serious injuries like fractures.