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Title: The effect of the AposTherapy system on knee biomechanics in recreational athletes at risk of a non-contact anterior cruciate ligament injury
Author: El-Zein, I.
ISNI:       0000 0004 7966 9232
Awarding Body: University of Salford
Current Institution: University of Salford
Date of Award: 2019
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An anterior cruciate ligament (ACL) injury is a catastrophic incident in sports, resulting in an extended period away from athletic participation and even potentially ending a playing career. The disparity between positive laboratory results of neuromuscular training programs and the actual effects on injury outcomes among high-risk populations suggests a missing link in current intervention programs. One proposed explanation for such a gap between laboratory results and incidence outcomes may be related to the time-consuming, complex and difficult implementation of the techniques found to be successful in reducing lower limb movement mechanics and neuromuscular risk factors. A novel option is to explore whether different unstable devices and unstable footwear designs may induce positive biomechanical and neuromuscular effects. The overall aim of this thesis was to determine the effect of an unstable device (AposTherapy system) on knee biomechanics and muscular recruitment patterns while performing functional tasks. To accomplish the research, four separate trials were conducted separatly. Firstly, a repeatability trial with 11 healthy physically active (male and female) participants was conducted to determine the reliability of the outcome measures for future studies. Secondly, as the AposTherapy system has not previously been trialled within the 'at-risk' female population, a feasibility study investigating whether using the AposTherapy intervention during a six-week period was feasible was conducted. This was followed by a randomised clinical trial amongst 32 female recreational athletes who were indicated to have a high-risk (2D FPPA > 8.4º) indication for sustaining a non-contact ACL injury. Three groups (control and two active intervention groups) were assessed at a six-week outcome point to determine changes in biomechanical outcomes. The results demonstrated positive biomechanical and clinical outcomes specifically in reducing the maximum knee valgus angle during a single leg landing task while only using the AposTherapy system for walking. Furthermore, a significant reduction in maximum hip adduction moments during study tasks was observed when the AposTherapy system use was coupled with additional exercise. The thesis concluded with preliminary study investigating five individuals who were deemed at risk of a second non-contact ACL on their contralateral limb following primary ACL reconstruction (ACLR) surgery. There was a significant reduction in knee valgus angle during the single leg landing and single leg squat tasks while only using the AposTherapy system for walking in the study with individuals who have had ACLR surgery. In summary, the results of this thesis showed that the AposTherapy system gave significant improvements in overall stability, with future studies needed to examine a larger-scale application especially in post-ACL reconstruction rehabilitation programs to mitigate the risk of a second ACL injury when athletes return to sport activities. However, more research should also focus on developing more affordable unstable footwear devices which could be incorporated in larger-scale prevention programs in the future.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available