“An ankle sprain is a common injury. Inversion-type, lateral ligament injuries represent approximately 85% of all ankle sprains. 

An ankle sprain is where one or more of the ligaments of the ankle are partially torn or stretched

When a ligament tears or is overstretched its previous elasticity and resilience rarely returns. 

• Grade I Mild - Little swelling and tenderness with little impact on function

• Grade II Moderate - Moderate swelling, pain and impact on function. Reduced proprioception, ROM and instability

• Grade III Severe - Complete rupture, large swelling, high tenderness loss of function and marked instability”

https://www.physio-pedia.com/Ankle_Sprain 

https://www.newsmax.com/health/health-news/sprained-ankle-effects-linger/2015/09/17/id/692065/