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Updated: Jun 5, 2026
Evaluating Postural Control and Lower-extremity Muscle Activation in Individuals with Chronic Ankle Instability
Published on: September 18, 2020
Decoding dynamic postural control: diagnostic insights from Y-balance test and force plate measures in chronic ankle
Roya Khanmohammadi1, Sadaf Sepasgozar Sarkhosh2, Zivar Beyraghi2
1Iranian Center of Excellence in Physiotherapy, Rehabilitation Research Center, Department of Physiotherapy, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran. dr.rkhanmohammadi96@gmail.com.
The Y-Balance Test (YBT), especially the posterolateral reach, and medial-lateral center-of-pressure (COP) velocity are effective for identifying chronic ankle instability (CAI). These measures offer practical screening and mechanistic insights for balance deficits.
Area of Science:
- Biomechanics
- Sports Medicine
- Clinical Assessment
Background:
- Chronic ankle instability (CAI) negatively impacts dynamic balance and anticipatory postural control.
- The diagnostic value of clinical versus laboratory measures for CAI is not well-established.
Purpose of the Study:
- Compare dynamic balance and anticipatory postural adjustments (APAs) during gait initiation (GI) in athletes with CAI versus healthy controls.
- Evaluate the diagnostic accuracy of the Y-Balance Test (YBT) and force plate-derived center-of-pressure (COP) parameters for CAI.
Main Methods:
- Sixty-two athletes with CAI and 31 healthy controls performed the YBT (anterior, posteromedial, posterolateral) and force plate assessments during GI.
- Receiver operating characteristic (ROC) analyses were employed to determine the discriminatory power of each measure.
Main Results:
- Athletes with CAI exhibited significantly reduced posteromedial and posterolateral YBT reach performance compared to controls.
- Medial-lateral (ML) COP displacement and velocity were lower in CAI groups.
- The posterolateral YBT reach demonstrated the highest diagnostic accuracy (AUC=0.957), followed by posteromedial reach (AUC=0.857). ML COP velocity also showed good diagnostic ability (AUC=0.783).
Conclusions:
- Posterior YBT directions (especially posterolateral) and ML COP velocity are reliable indicators of balance deficits in CAI.
- The posterolateral YBT serves as a practical, high-accuracy clinical screening tool.
- COP measures provide complementary mechanistic insights, and integrating both assessments can enhance evaluation.
