The relationship between lower extremity balance, objective, and subjective outcome measures in patients with ACL - deficient ACL - reconstructed knees

The purpose of the present study was to examine the relationship between single limb standing balance as measured by total Centre of Pressure (CoP) pathlength in a fixed time interval using the Wii™ Balance Board, objective outcome measures of knee function as assessed by single-legged hopping test, vertical jump test, isometric muscle strength of both the quadriceps and hamstring muscle groups, and common subjective knee rating scales in participants with ACL- deficient and ACL- reconstructed knees. Fit and physically active participants were recruited from the Sports Injury Clinic in Rockhampton Hospital. Participants were recruited to the ACL Deficient (ACLD) group with a clinical diagnosis of ACL rupture confirmed by MRI (n = 25, male = 13; female = 12; mean age = 29.0 ± 9.6 years). Similarly the participants for the ACL Reconstructed (ACLR) group were identified as those who have had an ACL reconstruction at least six months prior to recruitment (n = 25, male = 18; female = 7; mean age = 29.3 ± 9.4 years).

Pearson-product moment correlation analysis revealed that a statistically insignificant weakly negative correlations between the CoP measure and other independent variables in the ACLD group. Similarly statistically insignificant weak correlations were identified between the CoP measure and the variables examined in the ACLR group. The present findings indicated that no statistically significant relationship existed between CoP measure, subjective functional scores, and objective measures of muscle strength and power.