M.Tech. / Purpose: In soccer the re-injury rate of Hamstring muscle strains is between 12 and 14 percent. A previous or recent Hamstring injury is the most recognised risk factor for future injury. On recurrence of the injury, it tends to be more severe and disabling than the initial injury. Given the high recurrence rates, Hamstring injuries provide a significant challenge to the treating clinician. Knowledge surrounding optimal treatment and preventative measures is therefore critical (Hoskins and Pollard 2005). The aim of this study is to assess the effectiveness of lower lumbar spine segment adjustment, namely the L4/5 spinal level, in the contractile strength of the Hamstring muscle group in professional soccer players that have a history of a Hamstring strain. Design: Forty professional soccer players between the ages of 15 and 34 years with a history of a grade one or grade two Hamstring strain were considered for this study. Participants in this research were obtained from the University of Johannesburg inter-residence players and from the University of Johannesburg first soccer team. Two groups of twenty players were randomly assigned to one of two groups. Group A received spinal adjustive therapy (SAT) to the L4/5 spinal segment with an ultrasound treatment to their Hamstring muscle group and Group B will receive only the ultrasound treatment to the hamstring muscle group. Each participant was treated five times over a period of three weeks. Measurements: Before any intervention was given to either of the groups, Hamstring muscle contractile strength was first recorded using a Cybex system 2000. Hamstring contractile muscle strength measurements were taken again after the fifth treatment for both groups and compared to ascertain if there had been any change in the contractile strength of the Hamstring muscles. Results and Conclusion: Even though the two groups did not start at the same contractile strength for the Hamstring muscle in knee flexion, as measured a CCybex system 2000 possibly due to the selection criteria used in the study in terms of age and body weight of the participants, results showed that spinal adjustive therapy was more effective in improving the muscle contractile strength of the Hamstring muscle in knee flexion since there was a favourable difference in both Group A and Group B following intervention, but more so in Group A (in the once injured leg) which received spinal adjustive therapy due to a greater increase in the overall muscle contraction in the Hamstring muscle group. For the Chiropractic profession this opens huge potential with regards to the Chiropractic benefits and improving the functioning of professional soccer players.

Dissertation submitted in partial compliance with the requirements for the Master’s Degree in Technology: Chiropractic, Durban University of Technology, 2012. / Background: Hamstring muscle strains are a common musculoskeletal injury amongst athletes, with a high rate of recurrence that suggests room for improvement in the treatment and management of these injuries. Cibulka et al. (1986) suggest a possible link between injuries of the hamstring muscles and dysfunction of the sacroiliac joint. A study by Fyfer (2005) found that sacroiliac manipulation alone had a positive effect in the treatment of recurrent hamstring strains, but this was not combined with or compared to conventional treatment for muscle strain. Fox (2006) found that sacroiliac manipulation added to hamstring stretching increased the resultant flexibility of uninjured hamstring muscles. Objective: The purpose of this study was to determine the relative effectiveness that manipulation may have when combined with and compared to a regime of hamstring stretching and strengthening in the treatment of chronic hamstring strains. Method: Thirty two participants suffering from chronic hamstring injuries and concomitant dysfunction of the sacroiliac joint were randomly allocated into two treatment groups. Both groups attended six consultations over a period of three weeks. Group one received treatment in the form of proprioceptive neuromuscular feedback (PNF) stretching and resisted isometric exercises of the hamstring, and were taught a home routine consisting of static stretching of the hamstring and Theraband® exercises directed at the hamstring. Group two received the same treatment and home routine as those in Group one, with the addition of Chiropractic manipulation of the dysfunctional sacroiliac joint. Outcomes were obtained by using the Numerical Pain Rating Scale (NRS-101), inclinometer testing of passive straight leg raiser test, and algometer assessment of pain threshold in the injured hamstring muscle and ipsilateral sacroiliac joint. Results: Data was analysed using the SPSS version 18.0 (SPSS Inc. Chicago, Ill, USA). Subjective and objectives outcomes were measured quantitatively. The effect of the intervention was measured using repeated measures ANOVA testing. The time versus treatment group interaction effect assessed whether the effect of the different treatment over time is the same, with a p value of <0.05 being v considered significant. Both treatment groups showed improvement of outcomes, and manipulation showed a marginally non-significant trend of greater improvement with regards to sacroiliac joint algometry. Conclusion: This study did not provide conclusive evidence of either a benefit or no benefit of manipulation, but where non-significant trends were shown, it is likely that this was due to lack of statistical power and that with an appropriate a priori analysis being done a greater sample size may have shown the same effect to be statistically significant.

Mini-dissertation submitted in partial compliance with the requirements for the Master’s Degree in Technology: Chiropractic, Durban University of Technology, 2012. / Purpose: Patellofemoral Pain Syndrome is a common condition in all age groups, with a multifactorial etiology. This study aimed to investigate the association between the Quadriceps femoris muscle group, Hamstring muscle group and Adductor muscle group, and to establish the relationship between myofascial trigger points (MFTP’s) in these muscle groups and patellofemoral pain syndrome (PFPS). Methods: A cross-sectional, observational, quantitative non-intervention clinical assessment study was conducted at the Chiropractic Day Clinic at Durban University of Technology (DUT), to determine the extent of the PFPS, the MFTPs and thus the relationship between the two. The study included eighty patients with PFPS, who were recruited by convenience sampling. The results were captured using Microsoft excel and SPSS version 15.0 was used to analyze the data. Results: Quadriceps femoris muscle group MFTPs were noted in 92.5% of the patients (most prevalent being Vastus medialis TP1 (63.8%), Vastus lateralis TP1 (33.8%) and Vastus intermedius at 27,5%). Least common was Vastus lateralis TP2 only presenting in 2,5% of the patients. Hamstring muscle group MFTPs were found overall in 86.3% of patients (most prevalent being in Biceps femoris muscle (66%), and least prevalent being in Semitendinosus muscle (11,3%)). MFTPs were present in 64% overall of the Adductor muscle group (Adductor magnus muscle being the most common). Significant associations were made between the presence of MFTPs in the Vastus lateralis TP2 (p=0.00), Vastus medialis TP1 (p=0.046; 0.005; 0.004), the NRS and the PPSS. Also significant was the relationship between the NRS, PPSS and the Semimembranosus and Adductor magnus muscles indicated that these muscles were the most likely causes of pain even though they had fewer MFTPs than other comparable muscles. Conclusion: The outcomes of this study supports previous research indicating that an extensor dysfunction of the Quadriceps femoris muscle group may be of MFTP origin and indicates that other muscles in the thigh require further research indicating their role in the development of PFPS.

Background: Epidemiological findings indicate a higher risk of muscular thigh strain injury during the latter stages of both halves of soccer match-play, with muscular fatigue highlighted as a key etiological factor in injury causation. Anthropometric, biomechanical and physiological differences present in the Black African population may elicit unique thigh injury risk profiles, different from those of European and American players. Objectives: The purpose of the current research was to investigate the impact of soccer-specific fatigue on the risk of hamstring and quadricep injury in amateur Black African soccer players, in both the dominant and non-dominant legs. Methods: Participants were required to perform a soccer matchplay simulation (SAFT⁹⁰), consisting of multidirectional and utility movements, as well as frequent acceleration and deceleration. Selected physical, physiological and psychophysical responses were collected at specific time intervals throughout fatigue protocol performance. Results: Heart rate responses were observed to increase significantly (p<0.05) in response to the start of both halves, and remain elevated (but showing no further significant increase) during the performance of the remainder of the fatigue protocol. Significant (p<0.05) changes in both concentric and eccentric isokinetic variables of the knee flexors and extensors highlight the effect of muscular fatigue on performance in soccer match-play. Eccentric hamstring peak torque was observed to decrease significantly over time (60°.s⁻ₑ=17.34%, 180°.s⁻ₑ=18.27%), with significant reductions observed during both halves. The functional H:Q ratio at 180°.s⁻ₑ indicated a significant decrease over time (10.04%), with a significant decrease indicated during the second half of the SAFT⁹⁰ protocol. The passive half time interval did not result in significant changes in isokinetic variables. Isokinetic strength, work and power indicated no significant effects of leg dominance.. ‘Central’ and ‘Local’ ratings of exertion were observed to increase significantly (p<0.05) as a function of exercise duration. Conclusion: The overall reduction in both the eccentric hamstring peak torque and the functional strength ratio was illustrated to be similar to that of other soccer-specific fatigue research. As a result, the risk of thigh strain injuries is suggested to be similar regardless of playing level and race. These time dependent changes may have implications for competitive performance and increased predisposition to hamstring strain injuries during the latter stages of both halves of match-play