What is chronic ankle instability
Updated: Feb 18
1. Also known as CAI
2. Residual lateral instability leading to repetitive ankle sprains (usually affects ATFL, CFL, PTFL) and is a result of functional ankle instability, mechanical ankle instability, or a combination of the 2.
3. Feeling of “giving way”
4. 20% of acute ankle sprain patients develop chronic ankle instability (Al-Mohrej OA, et. al., 2016)
5. Acute sprain > deficits in proprioception, balance & strength > CAI
6. An inability to complete jumping and landing tasks within 2 weeks of a first-time lateral ankle sprain (LAS) and poorer dynamic postural control and lower self-reported function 6 months after a first-time LAS were predictive of eventual CAI outcome. (Doherty, C, et. al., 2016)
Introduction of Chronic Ankle Instability (CAI)
•The failure of functional rehabilitation after acute ankle sprain leads to the development of chronic ankle instability.
•Residual lateral instability leading to repetitive ankle sprains (usually affects ATFL, CFL, PTFL) and is a result of functional ankle instability, mechanical ankle instability, or a combination of the 2.
•Feeling of “giving way”
Pes Clavus classification
PES PLANUS CLASSIFICATION
Contributing factors for Chronic Ankle Instability
•Mechanical instability is due to the laxity caused by ligaments tears. Functional instability is due to proprioceptive and muscular deficits after ankle sprain. •Both mechanical and functional instabilities may be difficult to assess or distinguish and they most often occur as a combination in the development of CAI.
(C.E. Hiller, S.L. Kilbreath, 2011)
• Lower limb varus mal-alignment •Anatomical variations of the tibiotalar joint such as axis of rotation, talar dome radius or retroposition of the lateral malleolus.
(F. Bonnel, E. Toullec, C. Mabit, Y. Tourné, 2010)
•Pathologies with a proprioceptive deficit or imbalance in neuromuscular control.
Classification of Ankle Sprain
• Lower leg and hindfoot alignment
•Precise location of tenderness
•Active and passive ankle range of motion (ROM) in knee flexion and knee extension
•Joint laxity (Beighton scale)
•Manual muscle testing (especially peroneal and tibialis posterior)
–Chronic Ankle Instability Scale
–Cumberland Ankle Instability Tool (CAIT)
–Presence of Functional Ankle Instability
–Anterior drawer test
–Talar tilt test
Prepared by: Tan Jing Yu