Chronic Ankle Instability: Why Does the Ankle Still Feel Unreliable After a Sprain?

The short answer

After a lateral ankle sprain, some people continue to report repeated sprains, “giving way” or a feeling that the ankle cannot be trusted. Chronic ankle instability (CAI) is not defined by a single image or one balance test. It may involve mechanical ligament behaviour, range of motion, strength, sensorimotor control, confidence and the ability to complete the person’s real tasks.[1]

Feeling unstable does not prove that one ligament is still torn. It is a reason to assess the whole function-load relationship rather than relying only on massage, rest or a brace.

What can “giving way” represent?

Giving way may happen when the ankle has to react quickly on uneven ground, during landing, cutting, fatigue or a sudden change of direction. Reduced dorsiflexion, calf or peroneal weakness, slower balance reactions, residual swelling, altered movement strategy or fear of another sprain may each contribute. These are possible contributors, not a checklist that diagnoses every person.

The 2021 clinical practice guideline recommends a history and examination that consider ligament injury, range of motion, strength, balance, movement coordination and functional goals.[1] A cohort study following first-time lateral ankle sprain also showed that recovery and later instability are influenced by more than the initial injury label.[6]

Why massage or rest alone may not solve the problem

Massage may temporarily change pain or muscle tone, and rest may reduce an irritated response. Neither automatically rebuilds the rapid control, strength, endurance and task confidence needed for uneven ground, jumping or cutting. Systematic reviews suggest that balance, neuromuscular and strength training can improve selected functional and patient-reported outcomes, but the interventions and outcome measures vary.[2-4]

That evidence supports a progressive, individualised programme—not a promise that one exercise prevents every future sprain. External supports may be appropriate for selected tasks, but they should not replace reassessment and capacity building.

When are imaging or specialist input worth considering?

Further evaluation may be appropriate when giving way continues, swelling or tenderness persists, motion is restricted, the ankle catches, the person cannot perform a target sport task, or a coexisting cartilage, tendon or bone problem is suspected. Imaging should answer a clinical question; a normal or abnormal scan is not a complete functional assessment.

Surgery is not a standard answer for every person with CAI. The decision requires the degree of mechanical instability, functional limitation, associated pathology, quality of conservative care, sport goals and specialist opinion.

BAIZE Clinical Interpretation

This is an evidence-informed reasoning example, not a diagnosis, risk score or fixed total.

Capacity Profile

• Structural capacity: lateral ligaments, joint and osteochondral structures, and previous injury.
• Functional capacity: ankle range, strength, single-leg balance, landing, jumping, cutting and sport endurance.
• Biological capacity: pain, swelling, irritability and recovery after a sprain or training session.
• Recovery capacity: sleep, fatigue, training gaps, work and competition schedule.

Load Profile

• Mechanical load: uneven surfaces, running, jumping, landing, cutting, footwear and match volume.
• Physiological load: fatigue, consecutive sessions and concurrent lower-limb problems.
• Psychological load: fear of another sprain, avoidance or stiffening during high-risk tasks.

Based on the evidence above, a BAIZE working hypothesis could be that giving way is maintained by a mismatch across several capacity dimensions and current task demands; the sensation alone cannot prove the state of a particular ligament. Functional tasks and post-activity response are needed to test the hypothesis.

Possible decision pathway

• Build capacity: restore range, strength, single-leg control, landing and cutting in graded steps.
• Manage load: first adjust uneven ground, speed, direction changes, volume and recovery; use external support only as clinically advised.
• Reassess: record giving-way episodes, strength, dynamic balance, target-sport performance and next-day response.

What this means for a reader

If the problem is occasional mild discomfort, activity may be progressed within a tolerable response. Repeated giving way or recurrent sprains should not be managed indefinitely with massage or a brace alone. The goal of assessment is to identify the limiting factor and test it with repeatable tasks. Major deformity, inability to bear weight, rapidly increasing swelling, persistent numbness, a cold or discoloured foot or rapidly worsening pain require prompt medical assessment.

FAQ

Does repeated giving way mean I need surgery?

No. Surgery depends on mechanical stability, function, associated findings, the response to an adequate conservative programme and specialist opinion—not the number of episodes alone.

Does balance training work?

It can improve selected function and dynamic balance outcomes, but effects vary by person, programme and outcome measure. It should be combined with strength and task-specific reassessment.[2,3]

How long should I wear a brace?

There is no universal duration. Use and weaning should reflect the injury, task and professional assessment rather than a fixed online schedule.

Why can the scan be normal while the ankle feels unstable?

Imaging does not fully measure dynamic control, strength or confidence during a task. History, examination and functional testing remain important.

Can I keep running or playing sport?

Progress according to single-leg support, hopping, landing, cutting and next-day response, not only the absence of pain.

When should I seek specialist assessment?

Consider further assessment for repeated giving way, persistent swelling or pain, catching, marked motion restriction, inability to complete a target sport task or limited improvement after a well-structured programme.

References

1. Martin RL, Davenport TE, Fraser JJ, et al. Ankle Stability and Movement Coordination Impairments: Lateral Ankle Ligament Sprains Revision 2021. J Orthop Sports Phys Ther. 2021;51:CPG1-CPG80. DOI: 10.2519/jospt.2021.0302. PMID: 33789434. https://pubmed.ncbi.nlm.nih.gov/33789434/
2. Mollà-Casanova S, Inglés M, Serra-Añó P. Effects of balance training on functionality, ankle instability, and dynamic balance outcomes in people with chronic ankle instability: systematic review and meta-analysis. Clin Rehabil. 2021;35:1694-1709. DOI: 10.1177/02692155211022009. PMID: 34058832. https://pubmed.ncbi.nlm.nih.gov/34058832/
3. Luan L, Adams R, Witchalls J, Ganderton C, Han J. Does strength training for chronic ankle instability improve balance and patient-reported outcomes and by clinically detectable amounts? A systematic review and meta-analysis. Phys Ther. 2021;101(7):pzab046. DOI: 10.1093/ptj/pzab046. PMID: 33517464. https://pubmed.ncbi.nlm.nih.gov/33517464/
4. O'Driscoll J, Delahunt E. Neuromuscular training to enhance sensorimotor and functional deficits in subjects with chronic ankle instability: a systematic review. Sports Med Arthrosc Rehabil Ther Technol. 2011;3:19. DOI: 10.1186/1758-2555-3-19. PMID: 21939557. https://pubmed.ncbi.nlm.nih.gov/21939557/
5. de Vries JS, Krips R, Sierevelt IN, van Dijk CN. Interventions for treating chronic ankle instability. Cochrane Database Syst Rev. 2011;(8):CD004124. DOI: 10.1002/14651858.CD004124.pub3. PMID: 21833947. https://pubmed.ncbi.nlm.nih.gov/21833947/
6. Doherty C, Bleakley CJ, Hertel J, Caulfield B, Ryan J, Delahunt E. Recovery From a First-Time Lateral Ankle Sprain and the Predictors of Chronic Ankle Instability: A Prospective Cohort Analysis. Am J Sports Med. 2016;44(4):995-1003. DOI: 10.1177/0363546516628870. PMID: 26912285. https://pubmed.ncbi.nlm.nih.gov/26912285/
7. Ahern L, Nicholson O, O'Sullivan D, McVeigh JG. Effect of functional rehabilitation on performance of the Star Excursion Balance Test among recreational athletes with chronic ankle instability: a systematic review. Arch Rehabil Res Clin Transl. 2021;3:100133. DOI: 10.1016/j.arrct.2021.100133. PMID: 34589684. https://pubmed.ncbi.nlm.nih.gov/34589684/