| Summary: | Chapter one of this thesis offered a general insight on the anterior cruciate ligament (ACL) injury and the outcome measures of ACL rehabilitation while chapter two was a systematic review on the effects of “accelerated rehabilitation” after ACL reconstruction surgery. The review concluded that 5 out of 10 randomised control trial studies had demonstrated moderate relative effect sizes in terms of improved knee laxity, neuromuscular performance, range of motion and some patient-reported outcome measures following accelerated rehabilitation for patients with ACL reconstruction. Chapter three was a systematic review in which the genetic influence on responsiveness to strength conditioning and the outcomes of knee after ACL reconstruction were investigated. The findings revealed that intra-genotypic responses to strength conditioning were heterogeneous and that duration, intensity and frequency of strength conditioning were factors that contributed to the differential responses of genotypes in regulating gains in strength. Chapter four (study one) was a randomised control trial in which the effects of quantified accelerated conditioning rehabilitation, anthropometric and orthopaedic-related factors on the outcomes of knee performance were investigated following ACL reconstruction. Participants (n= 40) were prescribed either accelerated rehabilitation in the first 12 weeks post-surgery (n=20) or contemporary (n=20) ACL rehabilitation. Participants were assessed in four different testing occasions; pre-surgery (0), 6, 12 and 24 weeks post-surgery. The findings revealed there was significant group by leg by time interaction using ANOVA and repeated measures on the latter two factors with superior scores in the accelerated group for the change scores of some sub-sections of KOOS. When controlling for body mass, waiting time and unstructured physical activity, scores associated with objective neuromuscular measures showed significant interaction (group by time by leg) from pre-surgery to 12 weeks post-surgery with superior scores favouring the accelerated group. This showed that the accelerated rehabilitation offered advantages over the contemporary practice coincident with enhanced conditioning and that orthopaedic-related factors were influential in determining the outcomes of ACL rehabilitation. Chapter five (study two) explored the correlation amongst the objective and subjective functional and objective neuromuscular outcome measures. Participants from study one (n=40) took part in this study. While there was no correlation between the change scores of the objective functional (single leg hop) and the subjective functional (KOOS, K-SES, Lyhsholm, IKDC) outcome measures, the absolute scores associated with sub-sections of KOOS had shown the most consistent correlation with objective measures (KOOS and sensorimotor performance [SMP] of the quadriceps;-0.46, peak force of the quadriceps; -0.34, and anterior tibio-femoral displacement [ATFD]; -0.32). Change scores for SMP and KOOS and for the single leg hop and Lysholm showed the highest correlation in the hierarchy of objectively-measured determinants of knee functional performance. Overall, there was a lack of robust and significant linkage amongst the functional and objective neuromuscular outcome measures. Chapter six (study three) investigated the influence of angiotensin converting enzyme (ACE) I/D gene polymorphisms on the responsiveness of function and physical performance to rehabilitation training following ACL reconstruction. Participants (n=40) from the previous two studies participated in this study that involved obtaining blood samples for DNA and genotyping for ACE I/D polymorphism. The findings revealed that one (peak force for quadriceps) out of 5 objective functional and neuromuscular measures had shown significant interaction (ACE genotype by time by leg) in response to rehabilitative training favouring the D allele over the I allele group. It was concluded from this exploratory trial that there was some evidence to suggest that planning for ACLR rehabilitative care might be optimised by using the conditioning-response characteristics associated with the individual.s genotype of the ACE I/D. There was a 15% of variance in the peak force (quadriceps at 12 to 24 weeks post-surgery) favouring the D allele group, indicating that strength training could be possibly prescribed routinely earlier to patients carrying the D allele. The last chapter of the thesis (chapter seven) was a general discussion that synthesised the findings of all the three studies of the thesis including their limitations and future directions.
|
|---|
