BACKGROUND
Ankle sprain is one of the most common sports-related musculoskeletal injuries in youth and imposes a long-term injury burden despite its often overlooked innocuous initial presentation. Studies show that up to 70% of youth and adolescents with lateral ankle sprain (LAS) experience persistent symptoms, often extending into adulthood, with features consistent with progression toward chronic ankle instability (CAI). Although ankle sprain in youth is multifactorial, biomechanical deficits are modifiable and clinically important. While several biomechanical and neuromuscular deficits have been associated with CAI following LAS, few studies have prospectively tracked progression from index injury, and investigated variables vary substantially.
OBJECTIVES
To identify biomechanical factors associated with progression from index lateral ankle sprain to chronic ankle instability in youth and young adults, and to support clinical interpretation of a case using existing evidence.
STUDY DESIGN
Evidence-based case report integrating a clinical case with a targeted literature review.
METHODS
A targeted literature search was conducted in PubMed, Scopus, the Cochrane Library, and EBSCO-hosted databases to identify studies examining factors associated with progression toward chronic ankle instability following a first ankle injury. Systematic reviews and prospective cohort studies were prioritized.
The clinical case involved a 16-year-old recreational athlete with persistent ankle pain, swelling, and recurrent episodes of giving way 2 years after a first lateral ankle sprain despite completing rehabilitation. Clinical assessment identified increased ankle laxity, bilateral pes planus, and generalized joint hypermobility (Beighton score 6/9), with MRI confirming anterior talofibular ligament injury and associated osteochondral changes.
Data on biomechanical variables and clinical outcomes were extracted from the literature and analyzed to interpret the patient’s clinical course. Due to heterogeneity in study design and outcome measures, findings were interpreted across studies rather than statistically combined.
RESULTS
Across the literature, ligamentous laxity, impaired balance, and neuromuscular deficits consistently emerge as key factors associated with recurrent ankle sprain and ongoing instability. A considerable proportion of individuals continue to report symptoms such as pain and subjective instability several months after injury, although pain severity typically decreases after 1 year. Persistent pain beyond 12 months, particularly following a more severe index injury, may reflect incomplete tissue recovery and has been suggested as an indicator of progression toward CAI. Similarly, early ligamentous laxity may compromise passive joint stability and increase susceptibility to recurrent sprain, while impaired postural control and proprioceptive deficits can limit neuromuscular responses during dynamic tasks, further predisposing individuals to repeated injury and ongoing instability. The present case demonstrates the coexistence of multiple biomechanical vulnerabilities including ligamentous laxity, generalized joint hypermobility, and altered foot posture persisting years after the index injury. These converging deficits may drive progression to chronic instability despite conservative care, amplifying risk in youth and young adults.
CONCLUSION
In this case, persistent pain, increased ankle laxity, and impaired neuromuscular function support a biomechanical pathway toward chronic ankle instability. These findings highlight the importance of early identification and rehabilitation of biomechanical deficits after lateral ankle sprain to reduce progression in youth and young adults. |
