The relationship between personality, knee braces, and stiffness regulation after anterior cruciate ligament reconstruction

McGuire, Kelly E.
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University of Delaware
Context: After anterior cruciate ligament (ACL) reconstruction, the outcomes may vary widely with some returning to full function and participation while others cannot regardless of the existing mechanical stability. Certain personality constructs like sensation seeking, mental toughness, and kinesiophobia, may interact with joint stiffness regulation and the use of knee braces to affect one's rehabilitation, functional outcome and timely return to unrestricted physical activities. Objective: The purpose of this study is to determine if personality influences stiffness and investigate how braces may affect stability in ACL reconstructed patients compared to healthy controls, as well as determine if a relationship exists between personality, knee stiffness, and the knee brace. Method: 15 ACL reconstructed (ACLR) subjects with clearance to return to full participation and 14 healthy controls participated in the study. Subjects completed several psychometric surveys to analyze levels of sensation seeking, mental toughness, kinesiophobia and knee function. Participants completed a single legged hopping test with and without a functional knee brace (DonJoy Full Force, DJO Global). Reactive knee stiffness regulation was measured with a customized device in both the braced and non-braced conditions. Statistical Analysis: A 3 way analysis of variance (ANOVA) was used to compare knee stiffness between groups with both startle and brace conditions. Individual t-tests were used to detect personality differences between groups. A 2 way ANOVA was used to compare global rating of knee function scores between groups with and without a knee brace. A 2 way ANOVA was used to compare functional hop scores between groups with and without a knee brace. Pearson correlation coefficients were used to assess relationships between personality, function and stiffness. Results: The brace caused significantly greater knee stiffness than the non-braced conditions. There was significantly less knee stiffness when a subject was startled than when they were not startled. There were no significant differences in stiffness values between groups. There were no significant differences between groups with the hop test. The brace significantly increased time on the hop test. The ACLR group had significantly greater kinesiophobia. Correlations were found with both sensation seeking and mental toughness with knee stiffness. Conclusion: ACLR individuals are able to stiffen their knee like healthy controls and knee braces can increase passive reactive knee stiffness. Personality traits such as sensation seeking and mental toughness may influence knee stiffness regulation strategies.