Assessment of proprioceptive decline in chronic ankle instability: a comparative evaluation of sub-modalities

Recurrent ankle sprains in chronic ankle instability (CAI) individuals are strongly linked to impaired proprioception, but the specific mechanisms underlying these impairments remain incompletely understood. This is largely due to the complexity of the proprioceptive system, which comprises multiple sub-modalities such as kinesthesia, joint position sense, force sense, vibration sense and landing proprioception, with the characteristic deficits of these sub-modalities and their diagnostic sensitivity and specificity remaining unclear. This study aims to comprehensively assess proprioception in CAI individuals by pointing sub-modality deficits, and to identify the core sub-modality with the greatest clinical discriminative value for CAI.

Fifty-eight participants were recruited, including 29 with CAI and 29 healthy controls. They underwent a battery of proprioceptive assessments: kinesthesia via the Threshold to Detect Passive Movement (TTDPM) test, joint position sense through the Joint Position Reproduction (JPR) test, force sense with the Force Match (FM) test, vibration sense using the Vibration Detection Threshold test, and landing proprioception evaluated by the Ankle Inversion Discrimination Apparatus for Landing (AIDAL) test. Between-group differences were analyzed using independent samples t-tests, Mann-Whitney U tests, and AUC tests.

Higher passive perception thresholds in TTDPM tests (dorsiflexion: p = 0.03; inversion: p = 0.004; eversion: p = 0.018), higher absolute errors in FM tests (plantarflexion: p = 0.025; dorsiflexion: p = 0.043; inversion: p = 0.018; eversion: p = 0.014) and lower AIDAL score (p = 0.002) were detected in people with CAI. ROC curve analysis of the tests with significant intergroup differences revealed that the AIDAL exhibited the highest discriminative ability (AUC = 0.728).

Proprioceptive deficits in CAI are modality-specific, primarily affecting kinesthesia, force sense, and landing proprioception. Among the impaired sub-modalities, landing proprioception has the strongest predictive value for CAI and can serve as a key target for clinical assessment and rehabilitation intervention.