Postural Changes and Pain Levels in Patients with Unilateral Knee Injury

Introduction: Postural control is essential for balance and fall prevention but can be compromised by injuries such as anterior cruciate ligament (ACL) rupture and knee osteoarthritis (OA). ACL rupture affects proprioception and joint stability, while OA causes pain and stiffness, impacting mobility and muscle strength. The base of support, defined by the contact points of the body with the ground, is a crucial parameter in evaluating postural control. Objective: To assess changes in the base of support during bipedal postural control in young adults with complete ACL rupture and elderly individuals with unilateral knee osteoarthritis. Methodology: An observational and comparative study with 40 adults divided into two groups: G1 (elderly with unilateral knee osteoarthritis) and G2 (young adults with complete ACL rupture). The BaroScan® plantar pressure platform was used to collect data on the center of pressure (COP) and weight distribution. Pain perception was assessed using the Visual Analog Scale (VAS). Results: There was a significant difference in pain perception (VAS) between the groups (p = 0.04), with higher pain in G1. The mediolateral displacement of the COP (COPML) was also greater in G1 (p = 0.03). There was no significant difference in body weight distribution and anteroposterior displacement of the COP between the groups. Conclusion: Individuals with OA exhibit higher pain perception and greater mediolateral sway during postural control. Chronic pain and muscle strength loss may contribute to impaired postural control in the elderly with OA. In contrast, young individuals with ACL injuries may compensate for the injury with greater neuromuscular adaptation. Individual variability in response to pain and injury highlights the importance of personalized approaches in treatment and rehabilitation.