Orientador: Abílio Garcia dos Santos Filho / Banca: João Candido Fernandes / Banca: Paulo Kawauchi / Resumo: Considerando a importância da saúde da coluna vertebral do trabalhador e sua direta relação com a postura corporal dentro do ambiente laborativo industrial, este estudo teve como objetivo principal identificar as ocorrências de queixas de dores nos segmentos na coluna vertebral, relacionadas com a postura de trabalho em pé, adotada pelos funcionários do setor de produção Colorido em uma Indústria de Alimentos. Para tantos, utilizou-se, como procedimento metodológico, um questionário para obter informações sobre dados pessoais e dados profissionais, postura adotada em pé, posturas mais incômodas dentro do ambiente de trabalho (assinaladas pelo formulário de Ranney, 2000) e dores (apontadas por meio do Diagrama de Corllet e Manenica, 1980). Utilizou-se também o questionário Nórdico (Kuorinka et al., 1986), validado na cultura brasileira por Barros e Alexandre (2003) e adaptado para o estudo, a observação direta dentro da produção de trabalho e a análise postural através do Método Owas, aplicado pelo software Win-Owas. Foi feita uma pesquisa descritiva de um estudo de caso em um setor industrial, com uma amostra de 30 funcionários. Os principais resultados apontam que a postura "em pé" é adotada durante o trabalho, e 73,3% dos entrevistados relataram cansaço em consequência dessa postura, principalmente quando associados à torção de tronco, inclinação de tronco e elevação do braço acima da cabeça. Quanto as maiores reclamações de dores e desconfortos no corpo, o diagrama de Corllet e Manenica (1980), apontou a região lombar, seguida da região dorsal e pernas; e da região do pescoço, ombros e coxa direita. O Questionário Nórdico adaptado também revelou a região lombar, com 10 entrevistados (33,3%) como a área mais atingida pela sintomalogia musculoesquelética, acompanhada da região dorsal, com cinco entrevistados (16,7%) e um dos entrevistados... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Considering the importance of the worker's spine healthy, and its direct relation with the corporal posture of the industrial labor atmosphere. This study had as main objective to identify the occurrences of complains about pain in the spine segments, that are related to work adopted by the collaborators that have to remain standing in the production section of a food industry. For so, it was used as methodological procedure, a questionnaire to obtain information on professional and personal data, posture to remain standing, the most uncomfortable postures in the work environment (signed by the form of Ranney, 2000) and pain (pointed out by Corllet and Manenica Diagram, 1980). It was also used the Nordic questionnaire (Kuorioka et al., 1986), validated in the Brazilian culture by Barros e Alexandre (2003) and adapted for the study, the direct evaluation and, a direct observation was made in the work production, a postural analysis using the Owas Method, applied using the Win-Owas software. A descriptive research was made studying a case in the industrial sector, using 30 employees as a sample. It was noticed that the posture of remain stand up is adopted during work, and 73.3% of the people that was interviewed said that they felt tired in consequence of this posture, especially when associated with trunk twists, trunk inclination and elevate their arms above their heads. Most complains regarding pain through their bodies, by Corllet e Manenica (1980) pointed to the lumbar region, followed in the dorsal area and legs and in the neck area, shoulders and right thigh. The adapted Nordic questionnaire reveled the lumbar area, 10 interviewed people (33,3%) as the area most affected by musculoskeletal symptoms, next in the dorsal area, with five people interviewed (16.7%) and one of them (3.3%) felt pain in the cervical area, none reported pain in the hips area... (Complete abstract click electronic access below) / Mestre

A lombalgia, comum em muitas atividades profissionais acomete principalmente indivíduos que trabalham na condução de veículos motorizados. O objetivo deste estudo foi investigar a prevalência da lombalgia em motoristas de caminhão, bem como os fatores de risco relacionados à sua ocorrência. Para isso foi elaborado um questionário que abordou fatores como: idade, prática de atividade física e esportiva, hábitos gerais de saúde e questões relativas ao exercício profissional. Calculou-se também o índice de massa corpórea através da relação entre o peso corporal e o quadrado da estatura. Foram avaliados 489 caminhoneiros do sexo masculino e selecionados 410 para o estudo. Os resultados obtidos foram: a prevalência da lombalgia em 59% dos caminhoneiros; e dentre as variáveis estudadas apenas o número de horas de trabalho mostrou-se estatisticamente significante, sendo que o risco do caminhoneiro ter dor lombar aumenta 7% para cada hora de trabalho. / Low back pain is common in several kinds of professional activities mainly in people who drive a lot in their job. The aim of this study was to evaluate the prevalence of low back pain in truckers and the risk factors related to the occurrence of lumbar pain. For this, a questionnaire was elaborated including such as: age, physical and sports activities, general health habits and aspects related to the job. Besides, the index of corporal mass has been calculated, based on the relation between the truckers weight and his square height. 489 male truckers were evaluated and 410 have been selected for the study. The results showed that 59% of the truckers have suffered from low back pain, and among the different aspects which have been analysed, only the number of working hours has been more significant: for each working hour, the risk of truck driver in having lumbar pain increases 7%.

Low back problems are among the most common nonfatal occupational injuries reported in the United States, and account for substantial healthcare expenditures (e.g., medical care costs) and losses to worker productivity. A strong association has been well-documented between occupational exposure to repetitive trunk motion and low back problems, particularly among workers performing manual material handling (i.e., lifting) activities. A feature of repetitive motion believed important to the development of work-related musculoskeletal disorders (MSDs), including low back problems, is a lack of within-individual, between-cycle variation of physical exposure summary measures, e.g., when observed visually, the cycle-to-cycle motion pattern appears consistent. An active literature has emerged using concepts of motor control to improve ergonomists’ understanding of physical exposure variation (i.e., motor variability) arising from individual-level mechanisms during repetitive work. Fundamentally, for any particular individual, the onset of exposure to a repetitive physical activity (i.e., task training) involves a learning process during which motor control strategies are developed to accomplish the task effectively. The cycle-to-cycle variability of motor learning metrics, such as postural and task performance summary measures, has been observed to exponentially decay during task training. From an ergonomics perspective, a temporal reduction in postural variability may lead to greater cumulative loading and physiological fatiguing of the underlying muscle tissues (due to more consistent cycle-to-cycle movements), thus increasing MSD risk over time. However, it is not known if, or to what extent, physical task characteristics (e.g., work pace) modify the temporal behavior of motor variability during training of a repetitive occupational activity. Moreover, the relationships between motor variability, task performance, and muscle fatigue during occupational task training are not well understood. The goal of this dissertation was to present new information concerning occupationally relevant metrics of motor learning during training of a laboratory-simulated, repetitive lifting activity. In this study, participants performed 100 repetitions (i.e., cycles) of the lifting task in each of four experimental sessions (i.e., visits) at different combinations of box load (low or high) and work pace (slow or fast). Three main observations were discussed in this dissertation: (i) participants exhibited a greater temporal reduction in the cycle-to-cycle variability of trunk postural summary measures during training of a heavier-weighted and faster-paced lifting activity (Chapter 3), which may have facilitated increases in the efficiency and repeatability of box movements (Chapter 4), (ii) the cycle-to-cycle variability of the erector spinae (back) muscle activity summary measures increased, but the variability of the multifidus muscle activity summary measures decreased, over time during faster-paced lifting (Chapter 3), and (iii) a greater temporal increase in trunk postural variability (i.e., a more “flexible” trunk movement strategy) was generally associated with lesser electromyographic back muscle fatigue during training of the lifting task (Chapter 5). Collectively, these research findings may open pathways to the development of new task design criteria and ergonomic guidelines to promote motor variability in the workplace and, ultimately, improve workers’ musculoskeletal health.

80% of the American population experiences back pain and it is the most common cause of limited activity in people of age 45 and under. Determining the reasons for back pain and developing new ways to treat it have been extensively researched over the past decade. However, very little research has been done on low back pain of amputees. There are four million existing amputees living in America and 250,000 people become new amputees each year. 70% of this group is lower limb amputees and a large number use a prosthesis of some kind to aid in the functions of daily living (Amputation and Limb Deficiency). Not all amputees use a prosthesis because of pain involved, aesthetics, and cost. In order to increase the use of prosthetics among amputees, the reasons why they do not use them must be fully understood. With this knowledge better prosthetic designs can be created. The purpose of this study is to first determine the prevalence of back pain among lower limb amputees who use a prosthesis and then to quantify the accelerations in the spine of this group and compare it to subjects who are not amputees. The findings of this study will be used to determine if back pain is a common complaint, if it interferes with daily activities, and if the use of a prosthesis causes abnormal loads in the spine of amputees. A cross-sectional descriptive survey was created and distributed to lower limb amputees who use a prosthesis and to a control group. In addition to the survey, several subjects were recruited to wear an accelerometer located over the L5-S1 vertebrae and walk at several speeds down a pathway. A maximum acceleration was determined for each step as well as the difference in acceleration between opposing legs. Also measured was the effect of a leg length discrepancy (LLD) on accelerations and back pain. As a result of this research it was found that a high percentage of amputees experience back pain and the prevalence is higher than that of controls. It has shown that there is a difference between the acceleration patterns of amputees and non-amputees, but further research is needed to show that this difference is what causes the higher prevalence of back pain. The trend of side dominance and its increase with increased walking speed for amputees has been shown as well as a general population trend of increased acceleration of the spine with increased speed. In relation to walking speed, the study has also shown that the perception of speed among amputees is slower than that of controls. This study has also supported the notion that a difference in leg length could cause low back pain.

Les troubles musculo-squelettiques figurent parmi les principales causes d’arrêt de travail. Le mal de dos appelé aussi lombalgie est une des pathologies les plus fréquentes. La lombalgie est considérée aujourd’hui comme un véritable problème de santé publique. Les répercussions socio-économiques conséquentes résultent des lombalgies persistant plus de trois mois (lombalgies chroniques) qui affectent pourtant une minorité de sujets (moins de 10% des lombalgiques).Face aux coûts aussi importants de la lombalgie chronique et au regard du peu d’efficacité des traitements usuels, la recherche de prises en charge spécifiques se justifie. Aussi, l’objectif principal de ce travail est d’analyser les cinétiques de déconditionnement et de reconditionnement du rachis chez des sujets lombalgiques et, parallèlement, d’apprécier les effets d’un programme intensif et dynamique de restauration fonctionnelle du rachis sur différents profils de sujets lombalgiques (homme et femme, avec ou sans chirurgie, sédentaire ou actif, avec une douleur initiale élevée ou faible à modérée). Ce travail s’intéresse aux effets du temps, de l’entraînement ou du réentraînement et de facteurs spécifiques sur une population de sujets lombalgiques chroniques. Le reconditionnement des sujets lombalgiques chroniques est constaté à l’issue de 5 semaines de prise en charge (175 heures) dans un programme de restauration fonctionnelle du rachis (RFR). L’évaluation de ce type de programme confirme bien l’efficacité sur les plans physique, fonctionnel, psychologique et professionnel d’un programme multidisciplinaire dynamique et intensif de type RFR, proposé pour des sujets lombalgiques chroniques dont le niveau de déconditionnement est avancé mais stabilisé. Cette issue thérapeutique, bien que très coûteuse, conserve ses bénéfices jusqu’à 12 mois post-traitement et peut représenter une alternative intéressante à la chirurgie. La douleur intense prétraitement des sujets lombalgiques chroniques ne constitue ni un frein, ni une variable prédictive des réponses au programme. Des habitudes de vie physique active ou sportive sont recommandées chez les sujets lombalgiques chroniques souhaitant bénéficier d’une prise en charge RFR. / Musculoskeletal disorders are among the leading causes of sick leave or work injuries. Low back pain (LBP) is one of the most frequent disability and remains a public health issue. The consequent socioeconomic impact results from low backpain lasting more than three months (chronic low back pain) which nevertheless affects a minority of people (less than 10 % of the low back pain population). Seeing the importance of chronic low back pain costs and the poor efficiency of usual treatments, the research for specific care is justified. Thus, the main objective of this work is to analyze the kinetics of reconditioning and reconditioning of the spine in chronic low back pain patients and, at the same time, to appreciate the effects of an intensive and dynamic functional restoration program on various profiles of chronic low-back pain patients (male or female, with or without surgery, sedentary or active, with a high or a low to moderate initial pain). Thus, this work deals with the effects of time, of training or retraining and of specific factors on a chronic low-back pain population. The reconditioning of chronic low-back pain patients is noticed at the end of a fiveweek functional restoration program (175 hours). The assessment of this type of program indeed confirms the physical, functional, psychological and professional efficiency of a dynamic and intensive multidisciplinary program such as RFR program, proposed to chronic low back pain patients whose deconditioning level is advanced but stabilized. This therapeutic outcome, though very expensive, is still valid 12 months after the post-treatment and can represent an interesting alternative to the surgery. The pre-treatment of severe pain in chronic low back pain patients, does not constitute either an obstruction, or a predictive variable of the program performances. Having an active, physical and sporting life is recommended for chronic low back pain patients before treatment or to benefit from specific care.

Background: Non-specific low back pain is a growing problem in society. No treatment have shown satisfying results to reduce pain or disability for patients with non-specific low back pain, and 1-18% of these patients develop chronic low back pain. STarT Back Screening Tool (SBST) is an instrument for sub grouping patients with non-specific low back pain into low, medium or high risk of developing chronic low back pain and then modifying the treatment after the different needs of every patient. The purpose of this study was to do a systematic review, investigating validation of the SBST to evaluate the justification of its use by clinicians. Method: Pubmed, Cinahl and Medline was searched in February 2017 for studies investigating criterion validity, construct validity and content validity of the SBST. The author (JG) assessed risk of bias and extracted relevant data following the procedures of PRISMA-statement. Result: 15 articles were identified for inclusion in the review. 8 articles investigated criterion validity, 11 articles investigated construct validity and 1 article investigated content validity. Predictive validity showed heterogeneous statistical analysis and varying results, a narrative result was presented that showed marginal benefits for the use of SBST for prediction of future outcome. Concurrent validity was measured with Spearman’s rank correlation coefficient in all investigated articles, showing results between 0.34-0.802. Discriminant validity was measured with Area under the curve analysis in all articles, scoring between 0.69-0.92. Convergent validity showed a Pearson’s correlation between 0.708-0.811 and a Spearman’s rank correlation between 0.35-0.74. Conclusion: Because of heterogeneity of the results it is not possible to draw conclusive conclusions. However, results tend to show limited evidence for the use of SBST as a predictive instrument for patients with non-specific low back pain.

The purpose of this study was to evaluate the methods currently available to measure the functional outcomes of physiotherapy treatment for low back problems. As a preliminary step, all extant questionnaires were located and evaluated against practical criteria to determine their likely utility in clinical practice. This process identified a large number of questionnaires, however, only six back-specific questionnaires fulfilled the practical criteria for clinical application. Four of these questionnaires were selected for further evaluation along with a generic health status assessment instrument, the SF-36 Health Survey. Current recommendations suggest that a low-back specific and a generic questionnaire are required for comprehensive assessment of the impact of low back problems. The four back-specific questionnaires selected were the Oswestry Disability Questionnaire, the Quebec Back Pain Disability Scale, the Roland-Morris Disability Questionnaire and the Waddell Disability Index. An evaluation of the literature on the clinimetric properties of these questionnaires revealed that little information was available for the Quebec and Waddell questionnaires and no information was available for any of the questionnaires for a clinical population of people with low back pain seeking physiotherapy treatment in an Australian setting. The primary aim of the research was identify which, if any, of the questionnaires should be recommended for measuring outcomes of physiotherapy treatment for low back pain. Consecutive ambulatory (non-admitted) patients presenting for physiotherapy treatment at three public hospital physiotherapy outpatient departments, three community health services, and four private practices were invited to enter the study. Patients were included if they were seeking treatment for a low back problem, were aged 18 or over, and could read and write English. Subjects completed the questionnaires on two occasions six-weeks apart. One hundred and forty subjects returned the first set of questionnaires, and 106 the second set. The mean age of the sample at pre-test was 51 (SD 17) and ranged from 18 to 89 years. Sixty-six percent were female, 41% were employed and 12% were receiving compensation for their back problem. Duration of the back complaint was more than six weeks for 56% of subjects, and 60% reported five or more previous episodes or continuous pain. Referred pain in the buttock thigh or leg was reported by 70% of subjects. The first aim was to compare the questionnaires for acceptability and comprehensibility. Data quality was high for all the questionnaires (less than 5% missing data). As expected, subjects found the more complex SF-36 Health Survey more difficult to complete than three of the low-back questionnaires. However, less than 10% of subjects found any of the questionnaires more than a little difficult to complete. The next aim was to explore the internal structure and inter-relationships of the low-back questionnaires and the three physical scales of the SF-36 Health Survey (Physical Functioning, Role-Physical and Bodily Pain). Analysis of item-item correlation, item-total correlation and Cronbach�s alpha confirmed that all scales were internally consistent. Factor analysis confirmed item homogeneity (unidimensionality) of all questionnaires except the Roland-Morris Disability Questionnaire. The questionnaires were significantly intercorrelated, but correlations exceeded .70 only for the Oswestry, Quebec and Waddell questionnaires. The next aim of the research was to compare test-retest reliability of the questionnaires. The Oswestry, Quebec and SF-36 Physical Functioning scale had sufficient reliability and scale width for clinical application. Despite previous reports of high reliability, the Roland-Morris scale was significantly less reliable than several of the other questionnaires. This indicates the importance of establishing the measurement properties of a test in the population or setting in which it will be used. The Waddell Disability Index, and the SF-36 Role-Physical and Bodily Pain scales had insufficient scale width to be useful in clinical practice. More than 15% of respondents had an initial score on these scales that would not allow change to be detected with 90% confidence. The next aim of the research was to compare the responsiveness of the questionnaires. None of the questionnaires was consistently identified as more or less responsive than the others although two methods (effect size and Liang�s standardized response mean) suggested the SF-36 Bodily Pain scale was more responsive than some other questionnaires. A secondary aim of this section was to evaluate the validity of the many available responsiveness indices and a novel �reliable change� method. A �known groups� strategy was used to determine whether the responsiveness index could discriminate between the low-back relevant questionnaires and the SF-36 General Health scale, the scores of which did not change across the retest period. With the exception of the novel �reliable change� method the responsiveness indices were all found to be valid indicators of responsiveness. Guyatt�s Responsiveness Index, effect size and Liang�s standardized response mean discriminated at 95% confidence between the reference scale and all the low-back questionnaires. The standardized response mean, t-test, correlation and ROC methods discriminated between the reference scale and five or six of the seven other questionnaires. Guyatt�s index was recommended as the best of the criterion-based methods, and the effect size the best of the distribution-based methods. The three questionnaires identified as having sufficient reliability and scale width, the Oswestry, Quebec and SF-36 Physical Functioning scale, were next analysed for data fit to a Rasch model. All three questionnaires had good data fit and item function was not affected by time, age, gender or whether or not subjects reported avoiding bending. The final aim of this research was to identify by Rasch analysis items to supplement the SF-36 Physical Functioning scale. The new scale, named the Low-Back SF-36 Physical Functioning18, showed comparable reliability and responsiveness to the SF-36 Physical Functioning scale. Further research is required to establish the measurement properties of the Low-Back SF-36 Physical Functioning18 scale in an independent sample. However, it has the potential to improve the clinical measurement of function by providing clinicians with a single measurement tool for comprehensive assessment of patients with low back pain.

Background: In the clinical examination of patients with low back pain (LBP), musculoskeletal physiotherapists routinely assess lumbar spinal segmental motion by performing physical examination procedures such as observation of active range of motion and palpation of intervertebral motion. The validity of manual assessment of segmental motion, however, has not been adequately investigated. Methods: In this pragmatic, multi-centre, criterion-related validity study, 138 consecutive patients with LBP were recruited and examined by physiotherapists with postgraduate training in musculoskeletal manual therapy. Clinicians examined each patient�s spine for the presence of segmental motion abnormalities, described as lumbar segmental rigidity (LSR) and lumbar segmental instability (LSI), then referred the patients for flexion-extension (FE) radiographs. The physical examination procedures of interest were: 1) assessment of forward-bending (FB) active range of motion (AROM); 2) FB and backward-bending (BB) passive physiological intervertebral motion testing (PPIVMs) in the sagittal plane; and 3) central postero-anterior passive accessory intervertebral motion testing (PAIVMs). Sagittal displacement kinematics of the lumbar spinal segments were measured from the FE radiographs, and served as the criterion standard against which the clinical assessment results were compared. The kinematic parameters measured were sagittal rotation, sagittal translation, ratio of translation per degree of rotation (TRR), instantaneous axis of rotation (IAR), and centre of reaction (CR). Reference ranges for normal motion were calculated from the analysis of FE radiographs of 30 asymptomatic volunteers. The accuracy and validity of the clinical examination procedures were then calculated, and reported as sensitivity, specificity, and likelihood ratios for a positive test (LR+) and a negative test (LR-). Results: In patients with LBP, sagittal rotation LSR and sagittal translation LSR had a prevalence of approximately 5.7% (p <0.0005) in this cohort. Sagittal rotation LSI was not found in statistically significant numbers. Sagittal translation LSI was found at a prevalence of 3.6% (p <0.05). Abnormal TRR (23.3%), IAR (17.7%), and CR (16.5%) were more prevalent findings (all p <0.0005). Observation of the quantity of AROM, during FB, is not valid for the assessment of either total lumbar segmental sagittal rotation, or detection of individual segments with abnormal segmental motion. PPIVMs and PAIVMs are specific, but not sensitive, for the detection of rotation LSI and translation LSI. A positive test (grade 4 on a scale from 0 to 4) with BB PPIVMs may have some utility for the diagnosis of rotation LSI or translation LSI, with LR+ of 8.4 and 7.1 respectively (and 95% CIs from around 1.7 to 38). Likelihood ratio statistics for FB PPIVMs were not statistically significant. A positive test (grade 2 on a scale from 0 to 2) with PAIVMs may have some utility for the diagnosis of rotation LSI or translation LSI, with LR+ of 2.7 and 2.5 respectively (and 95% CIs from around 1.01 to 7.5). Neither PPIVMs nor PAIVMs were useful for the detection of LSR, or abnormal quality of motion as measured by TRR, CR, and IAR. Conclusions: Abnormal spinal segmental motion is associated with the symptom of LBP, in patients presenting to physiotherapists with a new episode of recurrent or chronic LBP, however prevalence is low due to highly variable lumbar segmental motion among asymptomatic individuals. Manual physical examination has moderate validity, but limited utility on its own, for the detection of translation LSI. Further research should investigate the utility of other clinical examination findings for the detection of lumbar segmental mobility disorders.

This thesis was initiated by an awareness of the impact of low back pain in Western society in general and Australian society in particular. The studies and experiments in this thesis contribute towards an understanding of chiropractic as a professional entity in Victoria and the nature of its clinical practice. The issue of male adolescent LBP has been explored and in addition to an epidemiological description of this clinical entity, its anthropometric dimensions have been documented. The qualitative review of the literature provides ample justification for the management of patients with LBP by chiropractors, using manual or manipulative techniques. The observational study of the Victorian context in which chiropractors are educated, registered, and entitled to practice, demonstrates that Victorian chiropractors are appropriate providers of manipulative health care. They perform the role of primary contact, primary health care providers with diagnostic, treatment and management skills focussed mainly on musculoskeletal conditions, but with a small proportion of practice based in the health or preventive context, and are well placed to provide the manual and manipulative services required in the management of LBP patients. The profession is shown to have strategies in place to ensure continued legal and community acceptance. The strategies include those at entry level to the profession, such as the legislative provisions of government and the competencies required for registration as instilled during the professional education process, and those which are more of the nature to maintain the integrity of professional practice, such as the " standards of practice" concept. These are important characteristics given it is shown that the Victorian chiropractic profession is not homogenous with respect to educational standards, has a disparate gender balance, the presence of a few non-registered 'chiropractors', and a disparity in utilisation patterns with a significant tail to the right. However the chiropractic profession is shown to hold a position of strength and leadership in the Australian context with respect to the provision of manipulative health care. Indeed, it could be said that chiropractors are at the leading edge of the quality process with respect to the provision of manipulative health care in Australia. The description of chiropractic practice shows a patient base of all ages, including adolescents, presenting with a range of possible diagnoses, often funded by a third party, and with a high proportion of return visits suggestive of patient compliance and satisfaction. It is convincingly demonstrated that persons with work-related LBP attend to chiropractors in Victoria and are effectively managed with the aim being the restoration of optimal spinal function and, in the case of work-injured patients, an early return to work. This thesis includes utilisation data which suggest only a minority of Victorian chiropractors practice outside the responsible parameters described above. The case-mix data and patient profiles presented in this thesis are congruent and complement each other, suggesting a high level of patient satisfaction indicated by the high proportion of return visits by regular patients and a faster, return-to-work by work-injured claimants. The point and sample prevalence of LBP in a population of suburban male adolescents is described and shown to be similar to those found in comparable Western societies. The data for a sample of traditional Australian male adolescents describes the LBP experience for the first time in such a population and emphasises the wide variance between societies which is now being identified in the literature. The LBP experience of a typical suburban Australian male adolescent is identified and described in terms of chronicity, frequency and episode duration. Typically the male adolescent with LBP has a chronic (> 90 d) problem with frequent episodes of pain (from 2 or 3 times a month to 2 or 3 times week) which last a few hours. The pain is a little limiting but allows the performance of the Activities of Daily Living. While some limitation of general sporting activity due to pain is experienced, school attendance is generally not compromised. A particular clinical instrument, the Metrecom computerised electro-goniometer, is studied and found to be appropriate for use in gathering anthropometric dimensions to test hypotheses relating to an association between anthropometric dimensions and LBP in a male adolescent population. The applied level of uncertainty of the instrument is within acceptable limits for these dimensions. The anthropometric study tests the broad null hypothesis that the mean of specific anthropometric dimensions would be equal among samples of male adolescents drawn from the Australian population. The actual groups are a Melbourne 'Pain' group, a Melbourne 'No Pain' group, and a 'Traditional No Pain' group. The pain group reported either current LBP or a positive history of LBP, while the 'no pain' groups denied either current or historical LBP. The alternate hypothesis will be shown to be proven for the dimensions 'sitting height', 'upper body' length, 'pelvic height', and the ratio of the 'upper:lower' body segment in a population of male adolescents with idiopathic or mechanical LBP. This thesis meets its objectives of describing the chiropractic profession and its practise in the Victorian context, demonstrates the prevalence of LBP in a male adolescent population, and identifies particular anthropometric dimensions associated with those who report a LBP experience. The fact that a number of anthropometric dimensions are detectable in adolescence may allow the development of appropriate screening programs which in turn may lead to the design and introduction of suitable prophylactic interventional programs for persons found to be potentially prone to idiopathic or mechanical LBP, at the least reducing the severity and at most reducing the onset of this expensive problem in adulthood. The ratio of the upper body segment to the lower body segment would appear to be most appropriate indicator; it is robust in that it is a prime dimension, easily accessible, and with a low level of measurement uncertainty. Most importantly it would appear to hold validity throughout adolescence as it does not have a linear relationship with age.

<p>Back pain has been reported to be the most common type of discomfort in all occupational groups. Studies have shown that dentists experience more neck, shoulder and back pain than practitioners in other occupational groups. This has caused an increase of social and economic costs of healthcare and increased frequency of sickness absenteeism in Western countries. About 72% of dentists experience back pain according to studies done in Western countries thus showing a very high prevalence among dentist. This study aimed to investigate the prevalence of back pain among dentistry undergraduate students. As there have been reports of high prevalence of back pain among dentistry students in<br /> Western countries.</p>