Most sprained lateral ankle ligaments heal uneventfully, but in some cases the  ligament’s elastic function is not restored, leading to chronic ankle instability. Ultrasound shear wave elastography can be used to quantify the elasticity of musculoskeletal soft tissues and may serve as a test of ankle ligament function during healing.

Forty-six ankles in 23 healthy male subjects aged 20–40  years underwent shear wave elastography of the lateral ankle ligaments. Each ligament was evaluated three times with the ankle relaxed.

The mean shear wave velocity at rest for the anterior talofibular ligament was 2.09  ± 0.3 (range 1.41–3.17); and for the calcaneofibular ligament 1.99 ± 0.36 (range 1.29–2.88). Good inter-observer agreement was found for the anterior talofibular ligament and calcaneo fibular ligament shear wave velocity measurements with the ankle in resting position.

There  was a significant difference in mean shear wave velocities between rest and stressed conditions  for both anterior talofibular ligament (2.09 m/s vs 3.21 m/s; p <0.001) and calcaneofibular liga ment (1.99 m/s vs 3.42 m/s; p <0.0001).

This study revealed that shear  waves velocities of the normal lateral ankle ligaments increased with applied stress compared  to the resting state.