Mechanical Energy Flow identifies compensatory strategies in elite taekwondo players with Anterior Cruciate Ligament reconstruction during a single Leg-Landing protocol

Abstract

Athletes with Anterior Cruciate Ligament reconstruction (ACL-R) demonstrate different compensatory patterns to keep their balance. These compensatory strategies can lead to different movement pattern that probably changes the way muscles are used during movement. Mechanical energy expenditure (MEE) and Mechanical energy compensation (MEC) which defines the net mechanical energy produced by muscles and the amount of muscle energy compensation with intersegmental energy transfer can show different patterns of energy generation, absorption, and transfer by muscles and energy transfer through the joints. The compensatory strategy associated with energy flow may provide essential information that can be used to improve rehabilitation programs and keep treatment better for athletes in their therapeutic strategies. The aim of this study was to evaluate the energy flow transferred between the lower extremity joints in athletes with ACL-R during single-leg landing to find their compensatory strategy. 15 ACL-R and 9 non-injured control elite taekwondo females volunteered in the present investigation and performed 3 single drop landing trials and the best one chosen. Inverse dynamic was used to evaluate eccentric and concentric mechanical energy expenditure and compensation of lower extremity joints during single-leg landing. Collected data from a real-time motion analysis system and Kistler force plate at a sampling frequency of 100 and 1000 Hz by using MATLAB software were analyzed respectively. Multivariate analysis of variance was conducted for statistical analysis(p<0.05). ACL-R athletes exhibited more eccentric MEC at knee joint and more eccentric MEE (not transfer) at hip joint compared with the healthy group. In contrast, more significant concentric MEC in healthy individuals observed at knee joint in compare with ACL-R athletes which exhibited more concentric MEE and no significant differences between the groups were observed at the Ankle joint during single-leg landing. Mechanical energy analysis is widely used for studying movements in patients with disabilities. Patients with ACL-R exhibited less mechanical energy transfer at the hip in compare with healthy athletes which means they may have used a ‘quadriceps avoidance’ pattern possibly serving to reduce energy power transfer from knee to hip during landing.