Sinus tarsi syndrome develops after spraining an ankle or caused by repetitive strain from running or walking on a flat foot. It results to continuous discomfort and tenderness on the outer area of the ankle due to soreness.
The sinus tarsi are small bony canal on the ankle under the talus ankle bone. It is between the talus and heel bone which is called the subtalar joint. There are plenty of ligaments, nerves and blood vessels that go through the sinus tarsi. It is important in maintaining proprioception and balance. Inflammation around the sinus tarsi area or injury of the ligaments can result to sinus tarsi syndrome.
Causes of sinus tarsi syndrome
- Instability of the subtalar joint following an ankle sprain. It usually develops after a single sprain or repeated injuries. It results to excessive movement of the subtalar joint and cause an inflammation known as synovitis and scar tissue will form in the sinus tarsi canal.
- Individuals who have over-pronated or flat feet are susceptible to sinus tarsi syndrome
- Repetitive actions such as sitting with the feet tucked underneath the body, foot position when dancing ballet and position of the trailing foot when playing baseball and softball pitchers.
- Tenderness can be felt at the opening of the sinus tarsi found outside the ankle.
- Difficulty running on a curve on the side of the affected ankle
- Pain in the sinus tarsi area and can be felt deep inside that becomes severe with prolonged walking or running and relieved with rest.
- The ankle becomes stiff especially in the morning and improves with movement.
- The area becomes unstable when performing exercises on uneven ground or slopes, jumping and changing directions quickly.
- Pain during movement of the ankle especially inversion such as turning the sole of the foot inwards and pointing the foot down or plantar flexion.
- Take of plenty of rest. Use crutches and an ankle brace for a short time to support the affected area, help when moving around and for fast healing of the condition.
- Take the prescribed over-the-counter non-steroidal anti-inflammatory drug (NSAIDs) such as ibuprofen to lessen the pain and inflammation. Another alternative is using electrotherapy such as ultrasound to lessen the swelling and inflammation due to sinus tarsi syndrome.
- Apply an ice pack on the affected area to lessen the inflammation and pain. Avoid applying the pack directly on the skin to prevent further damage and worsen the condition.
- Seek the help of the physical therapist for some rehabilitation exercises for joint mobility and taping to minimize movement of the subtalar joint and lessen the amount of movement and pronation by supporting the medial longitudinal arch of the foot.