Evaluation of movement variability and knee biomechanics during functional sporting tasks in healthy individuals and individuals following Anterior Cruciate Ligament Injury (ACL) and ACL reconstruction

Alyami, AMN

Abstract

Background
Injury to the anterior cruciate ligament (ACL) is a serious problem which can occur during some sporting activities. Knee biomechanics and movement variability (MV) comprise two very important aspects relating to injury risk, where it has been suggested that the latter may play a role in ACL injury.

Aim
The aims of this thesis were: to investigate MV and knee biomechanics during four common functional sporting tasks in a healthy cohort, as well as in individuals following ACL injury and following ACL reconstruction (ACL-RC); to investigate the effect of leg dominance and the effect of the individual tasks on MV and knee biomechanics; to investigate the relationship between MV and knee biomechanical risk factors; and to investigate differences in MV and knee biomechanics between all three groups.

Methods
Kinematic and kinetic data were obtained using 3D motion analysis and force platforms. Following examination of the reliability of 3D biomechanical outcome measures and MV outcome measures participants (45 healthy, 20 ACL deficient (ACL-DF) and 20 unilateral ACL reconstructed (ACL-RC) males) performed four different sporting tasks: running, cutting to 90 degrees, a single leg landing (SLL) and a single leg squat (SLS) with both limbs. The MV was assessed using coefficient of variation (CV) (the second order version). Differences were assessed between the two legs in each group, as well as differences between groups. The relationship between MV and knee biomechanical risk factors was also examined.

Results
Healthy
In terms of healthy group, the reference values for MV and knee biomechanics were provided. In addition, significant differences in MV and knee biomechanics were found to occur between tasks. Of all four tasks, cutting to 90 degrees demonstrated the highest values in terms of knee biomechanical risk factors (knee valgus moment), which indicates that it is the riskiest task, following by SLL. However, cutting to 90 degrees task demonstrated lower MV, as compared to the other tasks. In addition, no significant differences emerged in MV and knee biomechanics between dominant and non-dominant legs during all four tasks. A significant negative relationship was found to occur between MV and peak knee valgus moment during all four functional sporting tasks.
ACL-DF and ACL-RC
In terms of the ACL-DF group, the injured limb demonstrated a significantly lower peak knee extension moment, peak knee flexion angle and peak GRF than the uninjured one. However, it demonstrated greater MV than the uninjured one. Interestingly, the ACL-RC group reported similar findings to the ACL-DF cohort, where the reconstructed limb demonstrated a significantly lower peak knee extension moment, lower peak knee flexion angle and peak GRF than the uninjured one. However, the injured side demonstrated greater MV than the uninjured one.
Between three groups
In the comparisons between groups both the ACL-RC and ACL-DF groups demonstrated a significantly lower peak knee extension moment as compared to the healthy control group. They also showed a lower peak knee flexion angle than the control group during running, SLL and cutting tasks. In addition, both ACL-RC and ACL-DF groups demonstrated lower MV than the healthy control group. Importantly, the uninjured limb in the ACL-RC group demonstrated the greatest between-group knee valgus moment during SLL and cutting tasks.

Conclusion
ACL injury can significantly affect MV and knee biomechanics. In addition, MV should be considered when developing ACL injury risk mitigation and ACL reconstruction rehabilitation RTS programmes. As both the ACL-DF and ACL-RC cohorts displayed practically identical impairments in MV and knee biomechanics, this raises additional questions regarding rehabilitation and RTS programmes. The uninjured limb in the ACL-RC individuals reported the greatest knee valgus moment, which places it at higher risk of sustaining a second injury and, therefore, must be targeted during rehabilitation. These findings will be of assistance in the development of rehabilitation and RTS programmes for ACL-injured patients who either choose surgical or conservative treatment options. In addition, they will be of assistance when developing ACL injury/reinjury risk mitigation programmes.

Citation

Alyami, A. Evaluation of movement variability and knee biomechanics during functional sporting tasks in healthy individuals and individuals following Anterior Cruciate Ligament Injury (ACL) and ACL reconstruction. (Thesis). University of Salford

• Thesis Type: Thesis
• Deposit Date: Dec 17, 2020
• Publicly Available Date: Dec 17, 2020
• Award Date: Jan 1, 2019