A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand Gauteng, May 2018 / Background The trunk is the centre of the kinetic chain, connecting upper and lower limbs and transferring energy during movement. Proximal stability serves as a base for quality movements distally. Trunk muscle stability and strength-endurance are associated with sporting performance. Asymmetrical sport-specific adaptation in the morphometry of the trunk muscles has been investigated and described in cricket pace bowlers, but not linked to or described in terms of the association with bowling performance. Aim The aim of this study is to investigate the association between bowling performance and trunk muscle stability, strength-endurance and thickness in adolescent pace bowlers. Method In this observational cross-sectional study, bowling performance, namely ball release speed and accuracy, was measured by means of a radar gun and accuracy target in the outdoor nets of the respective schools, where the 46 pace bowlers, aged 13-18 years old, were invited from. Trunk muscle stability was measured as the level passed on the Sahrmann Stability Scale and strength-endurance as the failing time in seconds according to the Bourbon Trunk Muscle Strength Test. Ultrasound imaging measured the thickness of external oblique, internal oblique, transversus abdominis and lumbar multifidus in millimetre. Spearman’s correlations were used to determine associations between individual variables and a multiple linear regression analysis calculated predictors of bowling performance, including independent variables such as age, height and weight. Statistical significance was set at p<0.05. Results No association was found between trunk muscle stability and ball release speed (r=0.278; p=0.061) or accuracy (r=0.026; p=0.866). Stability, however, accounted for a 60.7% variance in ball release speed (p=0.004), increasing ball release speed by 3.570 units per unit increase in stability. Strength-endurance of the trunk muscle chains did not correlate to ball release speed (r=-0.039-0.214; p=0.154-0.796) or accuracy (r=-0.062-0.131; p=0.385-0.801). A moderate and fair relationship was found between ball release speed and transversus abdominis (r=0.543; p=0.0001) at rest and contracted (r=0.440; p=0.002), respectively. Non-dominant transversus abdominis showed a fair relationship with height at rest (r=0.458, p=0.001) and a moderate correlation with weight (r=0.625, p<0.001). On the dominant side, transversus abdominis at rest, showed a moderate relationship to ball release speed (r=0.564; p<0.001), height (r=0.539; p<0.001) and weight (r=0.611; p<0.001). Thickness of bilateral transversus abdominis at rest had an R-square value of .67 and ball release speed increased with 5.133 units for each unit increase in the thickness of the non-dominant transversus abdominis and 4.677 for that on the dominant side. Accuracy did not correlate with any independent variable, but weight (R-square value .207) was found to increase accuracy by .766 units for each unit increase. Bowling performance was found to be predicted by age (R-square value 0.084). Conclusion A direct association between bowling performance and trunk muscle stability and strength-endurance was not found. Trunk muscle stability – as a suppressor variable – was found to be a predictor of ball release speed. Trunk muscle thickness accounted for the variance in ball release speed and weight for that of accuracy. These findings implicate that adolescent pace bowlers may be able to improve ball release speed by increasing trunk muscle stability and bilateral transversus abdominis thickness. However, future research is needed to confirm this statement. / LG2018

MSc, Physiotherapy, Faculty of Health Sciences, University of the Witwatersrand / The Association between Trunk Muscle Endurance and Lumbar-Pelvic Instability in Adolescent Low Back Pain Françoise Lewis Supervisors: Wendy-Anne Wood, Benita Naude. Low back pain (LBP) is a common cause of discomfort in modern society, and the prevalence of LBP in the adolescent population is high and has a predictive value for the occurrence of LBP as an adult. The aim of the study was to investigate the association between adolescent LBP and trunk muscle endurance and lumbar-pelvic instability, as well as the association between trunk muscle endurance and lumbar-pelvic instability. Sports and physical activity participation, sedentary activity participation and a family history were also investigated as they have been identified in previous studies as potential risk factors. The study was a cross sectional study of 80 adolescents in grade 8 to grade 11, aged 12 to 17 year , at three high schools in Gauteng, who agreed to participate in the study. Data was collected by means of a validated questionnaire and a physical examination. The level of significance for as sociated factors was set at 0.05. The results revealed a lifetime prevalence of 82.50%, one year prevalence of 78.80% and point prevalence of 23.80%. Adolescents with LBP have decreased endurance of the trunk extensor muscles but increased endurance of the trunk flexor muscles, which is statistically significant (p=0.044) . Lumbar-pelvic instability is not associated with adolescent LBP. Extensor trunk muscle endurance and poor lumbar pelvic stability show an association (p=0.031), with those adolescents with decreased trunk extensor muscle endurance presenting with poor lumbar-pelvic stability. A family history of LBP is significant for point prevalence of LBP (p=0.012), and one-year prevalence of LBP is marginally significant (p=0.086). Low activity level particpation was reported by a large percentage of all subjects. Sedentary activity participation is moderate in the LBP group, but the results are not statistically significant . There is a need for preventative srategies to decrease the prevalence of adolescent LBP. Increased awareness of LBP and potential risk factors needs to be addressed.

Non-specific low back pain (LBP) has been associated with alterations in the biomechanical properties and muscle activities of the trunk, but it is unclear how these changes are related to the dynamic stability of the trunk. During sitting, the structures of the trunk stabilise the upper body counterbalancing external moments acting on the trunk. The aim of this research was to evaluate a range of biomechanical variables including the hip and lumbar spine joints range of motions, moments and powers the viscoelastic properties of the trunk, and the role of the muscles while a participant was performing a balancing task in sitting and to compare results between healthy and LBP subjects. A custom-made swinging chair was used to perform the balancing task. It was designed to challenge primarily the trunk and to minimise the effect of the lower limbs so that the role of the trunk could be examined in isolation. Twenty-four participants with LBP and thirty healthy participants were requested to sit on the custom-made swinging chair and to regain the balance after tilting the chair backward for 10° and 20º. Electromagnetic motion track system sensors were placed on the participants’ back, one at the sacrum level and one at the first lumbar vertebral level to measure hip and lumbar kinematics. One further sensor was placed on the chair to track its rotation, which was also the rotation of the lower limbs. Forces data were taken from a force-plate which was mounted at the bottom of the chair. Inverse dynamic equations were used to derive the muscle moment acting at the hip and lumbar spine joints using data from the force platform and the motion tracking system. Muscle power was then calculated by multiplying the muscle moment and the corresponding joint angular velocity. Trunk viscoelastic parameters were derived using a second order linear model combine trunk moment and motion. Chair motion and trial duration were used to evaluate dynamic stability and task performance, in particular, the angular displacement of the chair was fitted in an equation describing the underdamped second-order response to a step input to derive natural frequency and damping ratio and to evaluate possible differences between groups. Activities, reaction times and co-contraction of the trunk muscles were evaluated using surface electromyography (EMG). The surface electrodes were placed bilaterally on the erector spinae , rectus abdominus, external and internal oblique. Kinematic analysis showed that the hip range of motion increased whereas spine range of motion angle decreased in participants with LBP for both tilt angles (p. < 0.05). No significant differences were found in muscle moment and power between healthy and LBP subjects (p > 0.05). The duration of contraction of various trunk muscles and co-contraction were significantly longer in the LBP subjects (p < 0.05) when compared to healthy subjects, and the reaction times of the muscles were also significantly reduced in LBP subjects (p<0.05). Trunk stiffness was found increased for LBP subjects (p < .05) while no difference was found for damping coefficient. There were no significant differences between the 2 subject groups in the time required to regain balance, and in the dynamic stability parameters, the natural frequency and damping ratio. The present study showed LBP was associated with alterations in biomechanical variables; in particular stiffness, hip and lumbar spine joints kinematic and muscle responses were altered in subjects with LBP when compared with healthy group. However, these alterations did not affect dynamic stability and moment developed at joints level, suggesting that LBP subjects adopted a different strategy to maintain balance but with the same effectiveness as the healthy subjects without any worsening of the symptoms. This may suggest to clinicians to encourage patients to remain active rather than to avoid movements. On the other hand, compensatory strategies were achieved with increased co-contraction at the expenses of muscle efficiency. This may lead to muscle fatigue and increase in spinal stress. Future research should clarify if the observed biomechanical alterations in this study are consequences or causes of LBP; or if the biomechanical changes and pain operate in a vicious circle, reinforcing each other leading to chronic conditions. This would help achieve our ultimate goal of developing effective treatment strategies, and it is hoped that the work of this thesis has helped us take a significant forward towards this goal.

Low back pain (LBP) is a widespread problem affecting a number of people. Traditionally treated by nonoperative approaches the recent development of water currents and treadmills imbedded into pools has spurred physical therapists and athletic trainers to incorporate the use of aquatic therapy into their rehabilitation programs. OBJECTIVE: Determine if select trunk muscle activity levels are different in water-based exercises compared to land-based exercises. METHODS: 11 healthy male participants age 25.9 ± 5.53 years, whom did not have a history of and were not currently experiencing LBP or injury. Muscle activity was monitored via electromyography (EMG) at the rectus abdominis (RA), external oblique (EO), lower abdominals (LA), erector spinae (ES), and lumbar multifidis (MT). Each subject performed (1) maximum voluntary contractions (MVC’s), (2) land-based exercises, and (3) water-based exercises. A paired samples t test was used to compare abdominal bracing (ABbrace), abdominal hallowing (ABhol), Anterior/Posterior pelvic tilts (APTilts), and lateral pelvic tilts (LatTilts) between comparable land and water conditions; general linear model-repeated measures was run to compare the 11 different water exercises; ABbrace, ABhol, APTilts, LatTilts, physioball push down (PBPushDown), PB lateral flexion, PB transverse rotations, stationary marching, leg abduction, and wall sits with sagittal and transverse plane arm movements. Follow-up multiple comparisons (LSD) were performed between water exercises using a Holm’s corrected alpha level set at 0.05. RESULTS: Land-based exercises elicited greater EMG activity compared to water-based activities for all muscles (%MVC land vs. %MVC water): RA %MVC (8.3-19.3 vs. 2.1-9.7, P = .003-.029); LA %MVC (27-105 vs. 5.2-25, P = .001-.016); EO %MVC (13-59 vs. 4.8-24.5, P = .001-.303); ES %MVC (19.1-37.6 vs. 7.75-22.1, P = .001-.039) and MT %MVC (16-25.4 vs. 5.9-8.8, P = .00-.005). For water comparison ABbrace and PB exercises produced the most muscle activity while WallSitSag/Trans consistently produced the least muscle activity. CONCLUSION: Even with reduced muscle activity in the water, the calculated % mean MVCs were high enough (at or below 25% MVC) to provide muscle endurance and stability gains. With the information provided from the analysis of water exercise comparison, practitioners can effectively progress patients through a rehabilitation program.

Background: The abdominal muscles are vital in providing core stability for proper function in most activities. There is a correlation between side asymmetry of theses muscles and dysfunction. Thus, the purpose of this study was to evaluate and compare trunk muscle morphology and trunk rotational strength between sprinters, a symmetrical sport and sprint hurdlers, an asymmetrical sport. Methods: Twenty-one trained collegiate sprinters and sprint hurdlers were recruited for the study (12 M, 9 F), average age (years) 20.2   1.5, height (cm) 176.9   9.1, and weight (kg) 70.6   9.8. Using real-time ultrasound, panoramic images of the internal oblique (IO) and external oblique (EO) were obtained at rest and contracted in a seated position for both right and left sides of the trunk. Results: Average trunk rotation strength to the right was greater among all participants, p < 0.001. The IO had greater thickness changes than EO for all participants. The IO side asymmetry was significantly different between groups p < 0.01. Conclusion: Sprinters, although involved in a seemingly symmetrical sport, exhibit asymmetrical trunk morphology and rotational strength, while hurdlers, involved in a unilaterally demanding sport, exhibit the expected asymmetry in muscle morphology and trunk rotational strength.

No description available.

The main purpose of this study was to determine whether playing soccer at high intensity training for a long period causes degeneration of the lumbar spine or not. This degeneration may occur without any symptoms or low back pain. Results of the present study were discussed in the framework of lumbar disc degeneration, trunk strength, lumbar and hip bone mineral density, trunk flexibility, activity MET scores for active and veteran soccer groups. There have been four subject groups in this study (15 active soccer players, 15 sedentary participants, 14 veteran soccer players, 13 sedentary participants). The BMD was measured in anterior-posterior view with a second-generation dual energy X-ray absorptiometry (DEXA) device. Isokinetic trunk strength data were recorded with the Biodex System Dynamometer (Biobex Medical Inc, Shirly, NY) at the 60&ordm / /sec and 120&ordm / /sec. Plain lateral radiographs were taken. The presence of degenerative changes of each lumbar vertebra was determined by using the Kellgren and Lowrence Score. A modified Schober test was used to measure lumbar flexion. Findings of the study demonstrated that veteran soccer players displayed greater lumbar disc degeneration than other groups. Moreover, v active soccer group had more BMD than other groups, but the veteran group&amp / #8217 / s BMD results were not different while comparing the control participants. Isokinetic test findings of the current study, trunk extension strength at 60/sec was significantly higher in active 1st group players than 2nd group participants, but there were no significant differences between the 1st group and 2nd group in terms of trunk flexion strength and agonist/antagonist ratio at 60/sec. In conclusion, Findings of the study support the main hypothesis that playing soccer at high intensity training at a long period of time may cause lumbar spine degeneration. Degeneration may occur without low back symptoms. Moreover, results supported the idea that Soccer can be accepted an impact loading sport that are to keep or accelerate bone mineral density. At last, having abnormal trunk extension strength while playing actively may cause lumbar disc degeneration on the spine at later years. A similar study should be carried out with a larger number of subjects, and longitudinal studies should be designed to examine the factors that effect the degeneration on the lumbar spine.

Darbo tikslas: Įvertinti liemens raumenų ištvermės ir statinės pusiausvyros rodiklių sąsajas asmenims, jaučiantiems lėtinį apatinės nugaros dalies skausmą. Darbo uždaviniai: 1. Įvertinti liemens raumenų ištvermę prieš ir po reabilitacinio gydymo taikant stuburo stabilizacinę funkciją gerinančius pratimus. 2. Įvertinti statinę pusiausvyrą ir skausmo intensyvumą prieš ir po reabilitacinio gydymo taikant stuburo stabilizacinę funkciją gerinančius pratimus. 3. Nustatyti liemens raumenų ištvermės, statinės pusiausvyros ir skausmo intensyvumo rodiklių sąsajas prieš ir po reabilitacinio gydymo taikant stuburo stabilizacinę funkciją gerinančius pratimus. Tiriamųjų kontingentas: Tyrime dalyvavo viena tiriamoji grupė, kurios narių skaičius buvo 29 pacientai: 11 vyrų ir 17 moterų; 1 tiriamasis tyrimo neužbaigė, kadangi gydymo eigoje atsisakė jame dalyvauti. Tiriamųjų amžiaus vidurkis buvo 46.32±0,92 metai ir svyravo intervale nuo 38 iki 55 metų. Tyrime taikyti metodai: Statinis nugaros tiesiamųjų raumenų ištvermės vertinimas pagal Ito (1996) ir McIntoch (1998) testus; Statinės pilvo lenkiamųjų raumenų ištvermės vertinimas pagal McIntoch (1998) ir McGill (2002) testus; Statinės šoninių liemens raumenų ištvermės vertinimas pagal McGill (2002) testą; Skausmo intensyvumas vertintas skaitmenine analogijos skale; Statinė pusiausvyra vertinta „Sigma Balance“ platforma. Rezultatai ir išvados: įvertinus liemens raumenų ištvermę, statinę pusiausvyrą ir skausmo intensyvumą prieš ir po... [toliau žr. visą tekstą] / Aim of the thesis is to evaluate correlation between trunk muscle endurance and indicators of static balance for people suffering from chronic low back pain. Goals of the thesis: 1. Assess trunk muscle endurance before and after rehabilitative treatment that involves spine stabilization exercises. 2. Assess static balance and intensity of pain before and after rehabilitative treatment that involves spine stabilization exercises. 3. Determine the correlation between trunk muscle endurance and indicators of static balance and pain intensity before and after rehabilitative treatment that involves spine stabilization exercises. Research group: the research was performed using a single research group that involved 29 patients: 11 men and 17 women; 1 subject refused continuing participation in the research in the course of the treatment. The average age of the subjects was 46.32±0.92 years and varied in the interval from 38 to 55 years. Methods applied in the research: evaluation of static endurance of the trunk extensor muscles applying Ito, (1996) and McIntoch (1998) tests; evaluation of static endurance of the abdominal flexors applying McIntoch (1998) and McGill (2002) tests; evaluation of static endurance of the lateral trunk muscles applying McGill (2002) tests; Pain intensity was evaluated using digital analogue scale; Static balance was assessed using balance platform SIGMA. Results and conclusions: after assessing the endurance of trunk muscles, static balance and pain... [to full text]