Pain in the ankle that occurs specifically when rotating the foot outward—a motion known as eversion or external rotation—indicates stress on the structures that resist or facilitate this movement. This specific pain pattern helps pinpoint the injury location, often involving the medial (inner) side of the ankle, the high ankle joint, or the lateral (outer) tendons that control the motion. The causes of this rotational pain range from sudden traumatic sprains to chronic structural issues that have developed over time. Understanding the distinction between injuries to ligaments (passive stability) and tendons (active movement) is the first step in determining the source of discomfort.
Ligament Strains and Sprains
Outward rotation of the foot places significant tension on the ligaments designed to limit this movement, primarily involving the medial ankle and the high ankle complex. The medial side is stabilized by the strong, fan-shaped Deltoid Ligament, which resists excessive outward rolling of the foot. When a traumatic event forces the foot into extreme eversion, the Deltoid Ligament can be stretched or torn, resulting in an eversion sprain.
This type of injury is less common than the typical inward-rolling ankle sprain, but it is often more severe due to the inherent strength of the ligament and its association with potential fractures. Pain, swelling, and tenderness are localized directly on the inner side of the ankle bone (medial malleolus). Severe Deltoid Ligament tears can allow the ankle joint to become unstable, potentially leading to long-term problems if not treated properly.
A Syndesmosis injury, often called a “high ankle sprain,” also results from external rotation. This injury affects the ligaments that connect the two lower leg bones, the tibia and the fibula, just above the ankle joint. The mechanism typically involves the foot being planted, flexed upward (dorsiflexed), and forcefully rotated outward.
This external rotation forces the ankle bone (talus) to push the tibia and fibula apart, straining the syndesmotic ligaments. Pain is felt higher up than a typical sprain, usually in the front and outside of the ankle. This pain is characteristically reproduced when the foot is rotated outward, and high ankle sprains often require a longer recovery time compared to common lateral ankle sprains.
Peroneal Tendon Dysfunction
The Peroneal tendons run along the outside of the ankle and execute the outward rotation movement. When these tendons are dysfunctional, active outward rotation becomes painful, indicating strain or instability within the tendon structure itself. This dysfunction commonly presents as tendinopathy or subluxation.
Peroneal Tendinopathy involves irritation or inflammation due to overuse or repetitive strain, common in runners or athletes who engage in frequent directional changes. The pain is typically felt behind the outer ankle bone and worsens with activity, especially when actively turning the foot outward. This condition can also develop in people with high arches, where the foot’s mechanics place additional stress on the tendons.
Peroneal Tendon Subluxation is an acute injury where one or both tendons slip out of the groove behind the outer ankle bone. This usually happens during a sudden, forceful contraction of the peroneal muscles, often accompanying an ankle sprain. The tendon is held in place by a band of tissue called the superior peroneal retinaculum; a tear in this structure allows the tendon to shift. Patients often describe a distinct popping or snapping feeling on the outside of the ankle as the tendon moves out of and back into its proper position.
Structural and Joint-Related Causes
Several mechanical or anatomical issues within the ankle joint can cause pain during rotation. Ankle impingement occurs when soft tissues or bone spurs are compressed between the ankle bones during movement. Anterolateral impingement, located in the front and outer part of the ankle, causes localized pain aggravated by external rotation. This condition often develops following previous ankle sprains, where scar tissue or inflammation accumulates in the joint space, leading to chronic discomfort.
Osteochondral Lesions (OCLs) of the talus involve damage to the cartilage and underlying bone of the joint surface. These lesions are typically caused by traumatic injury, such as a severe ankle sprain, which creates a focal area of injury on the dome of the talus. Rotational movements can cause the damaged area to be ground or compressed against the shin bone, resulting in deep, chronic pain and sometimes a clicking or catching sensation.
Tarsal Coalition is an abnormal connection between two or more bones in the rearfoot. This structural cause restricts the normal, subtle movement of the foot bones required for proper gait and rotation. The resulting rigidity and lack of natural shock absorption lead to localized pain when rotational stress is applied. The body often develops secondary muscle spasms or tendinopathy as it compensates for the fixed joint, further complicating the diagnosis.
Understanding When Medical Intervention is Necessary
While many minor strains can be managed with initial at-home care, certain signs suggest the injury is more serious and requires professional evaluation. If you experience a sudden, sharp onset of pain accompanied by a distinct popping or tearing sound, this can indicate a significant ligament or tendon tear.
If you experience any of the following, seek medical attention:
- The inability to bear weight on the injured foot, even after a few hours, which suggests a bone fracture or severe ligament involvement.
- Significant swelling, bruising, or a visible deformity of the ankle joint.
- Pain that is persistent and does not begin to improve after 48 to 72 hours of rest, ice, and anti-inflammatory medication.