Lower limb
Calcaneofibular ligament (CFL)
Ligamentum calcaneofibulare (CFL)
- Origin
- Tip of the lateral malleolus
- Insertion
- Lateral surface of the calcaneus, passing deep to the fibular tendons
- Function
- Checks inversion in neutral and in dorsiflexion, and is the only lateral ligament that stabilises both the talocrural and the subtalar joint.
- Innervation
- Superficial fibular nerve
- Movement & chain
- Runs almost vertically in neutral and tightens as soon as the foot moves into dorsiflexion. It takes over from the ATFL exactly when that ligament goes slack.
- Palpation
- From the tip of the lateral malleolus straight caudally and slightly posteriorly. It lies deeper than the ATFL, beneath the fibular tendons; press through gently and compare with the other side.
- Clinical
- Injury here almost always means the ATFL is torn too: it is the second ligament to give way. The talar tilt test examines it. When both subtalar and talocrural stability are gone, recovery takes noticeably longer.
- Segmental innervation
- Segmentally L5-S1
- In clinical practice
- With persisting lateral instability after months of training, this is the ligament assessed on MRI before reconstruction is considered.
- Region in the model
- Lower limb