Deficits in single-limb stance more than 20 years after ACL injury

Abstract

Aim: To investigate the long-term effect on balance during single-limb stance after unilateral anterior cruciate ligament (ACL) injury across two groups who had rehabilitation including ACL reconstruction (ACL_R) or a tailored physiotherapy program (ACL_TPP), compared with knee-healthy controls. Methods: Single-limb stance was monitored for floor-supports with the contralateral foot. Single-limb stance without floor-supports was assessed with analyses of center of pressure (CoP) for further discrimination. Comparisons were made between ACL_R (n = 28) and ACL_TPP (n = 28) and with controls (n = 18). The injured and uninjured legs were compared within ACL-injured subjects. Results: Single-limb balance was equally inferior in both ACL-injured groups and on both legs compared with knee-healthy controls. In ACL_R and ACL_TPP, 39% and 50%, respectively, failed to stand on one leg without floor-supports with the contralateral foot. No contralateral supports occurred in knee-healthy controls. CoP measures for subjects who stood without contralateral floor-supports did not reveal any further differences. Older age and higher body mass index (BMI) correlated with larger migration of CoP. Conclusion: Inability to stand without contralateral supports showed that balance in single-limb stance was inferior in ACL-injured subjects, independently of which initial treatment that was given. Age and BMI need consideration in studies assessing balance in single-limb stance.

Key words::

• Balance
• CoP
• knee
• long-term perspective

Acknowledgements

This study was funded by the Swedish Scientific council (K2008-70X-20845-01-3), Umeå University (Young Researcher Awardee C Häger) and Ingabritt & Arne Lundberg's research foundation. The authors like to thank Professor Yelverton Tegner and Lars Lundgren for their initial contributions and Professor Kjell G. Nilsson for critical comments on the manuscript.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.