Unraveling the Complexity of Low Back Pain.

Low back pain (LBP) is the leading cause of disability worldwide. Various approaches to diagnose and manage LBP have arisen, leading to an exponential increase in health care costs. Paradoxically, this trend has been associated with a concurrent increase in disability and chronicity. The health care system faces enormous challenges, with both the disability burden and financial impact relating to LBP escalating. Growing evidence suggests that current practice is discordant with contemporary evidence, and is in fact often exacerbating the problem. Change will demand a cultural shift in LBP beliefs and practice. J Orthop Sports Phys Ther 2016;46(11):932-937. doi:10.2519/jospt.2016.0609.

An exploration of familial associations of two movement pattern-derived subgroups of chronic disabling low back pain; a cross-sectional cohort study.

BACKGROUND: Altered movement patterns with pain have been demonstrated in children, adolescents and adults with chronic disabling low back pain (CDLBP). A previously developed classification system has identified different subgroups including active extension and multidirectional patterns in patients with CDLBP. While familial associations have been identified for certain spinal postures in standing, it is unknown whether a familial relationship might exist between movement pattern-derived subgroups in families with CDLBP. OBJECTIVES: This study explored whether familial associations in movement pattern-derived subgroups within and between members of families with CDLBP existed. DESIGN: Cross-sectional cohort study. METHOD: 33 parents and 28 children with CDLBP were classified into two subgroups based on clinical analysis of video footage of postures and functional movements, combined with aggravating factors obtained from Oswestry Disability Questionnaire. Prevalence of subgroups within family members was determined, associations between parent and child's subgroup membership was evaluated using Fisher's exact test, and spearman's correlation coefficient was used to determine the strength of association between familial dyads. RESULTS: The majority of parents were classified as active extenders, sons predominately multidirectional and daughters were evenly distributed between the two subgroups. No significant association was found when comparing subgroups in nine parent-child relationships. CONCLUSIONS: The exploration of a small cohort of family dyads in this study demonstrated that children's movement pattern-derived subgroups could not be explained by their parents' subgroup membership. These results cannot be generalised to the CLBP population due to this study's small sample. Larger sample studies are needed to further elucidate this issue.

Differences in spinopelvic kinematics in sweep and scull ergometer rowing.

OBJECTIVE: The spinopelvic kinematics of sweep and scull have yet to be investigated, despite evidence suggesting that sweep rowing may be provocative for low back pain (LBP). The aim of this study was to determine whether differences existed in spinopelvic kinematics in high-level rowers without LBP in sweep and scull ergometer rowing. DESIGN: Repeated measures study. SETTING: Institute of Sport Laboratory. PARTICIPANTS: Ten high-level rowers. INTERVENTIONS: Kinematics of the pelvis, lower lumbar, upper lumbar, and lower thoracic regions during the drive phase of the rowing stroke were measured while rowing on an interchangeable sweep/scull ergometer. MAIN OUTCOME MEASURES: Total and segmental spinopelvic kinematics. RESULTS: Sweep rowing showed greater lateral bend (P < 0.05) throughout the stroke, which was predominately due to movement of the upper lumbar and lower thoracic regions. Furthermore, sweep rowing displayed a greater magnitude (P < 0.05) of axial rotation at the catch (created at the pelvis). Both sweep and scull rowing showed values close to end range flexion for the lower lumbar spine at the catch and early drive phases. No difference (P > 0.05) was evident in lateral bend or axial rotation values for the lower lumbar region. CONCLUSIONS: Some differences exist in spinopelvic kinematics between sweep and scull ergometer rowing. However, it may be speculated that the lack of differences in lateral bend and axial rotation at the lower lumbar spine in sweep rowing may represent an adaptive and protective approach of experienced rowers. This may be the focus of future research studies.

Sitting postures and trunk muscle activity in adolescents with and without nonspecific chronic low back pain: an analysis based on subclassification.

STUDY DESIGN: A preliminary cross-sectional comparative study of adolescents with nonspecific chronic low back pain (NSCLBP) and healthy controls. OBJECTIVE: To investigate whether differences in spinal kinematic and trunk muscle activity exist in both usual and slump sitting in adolescents with NSCLBP. SUMMARY OF BACKGROUND: Evidence suggests that low back pain commonly develops in adolescence and increases the risk for low back pain in adulthood. Sitting is an important consideration in adolescents with NSCLBP: currently there are no reports investigating their motor control strategies in sitting. METHODS: Twenty-eight adolescents (14 female) with NSCLBP and 28 matched pain-free controls were recruited from a large cohort study. Pain subjects were subclassified based on O'Sullivan's classification system. Three-dimensional lumbo-pelvic kinematic data and the activation of 3 back and 2 abdominal muscles were recorded during usual and slump sitting. The flexion-relaxation phenomenon in sitting was also investigated. RESULTS: Spinal posture in usual and slump sitting were similar for adolescents with and without NSCLBP. However, differences were identified in both sitting conditions when those with NSCLPB were subclassified and compared with controls. Muscle activation differences were not consistently identified, with only lower levels of internal oblique activation in usual sitting in NSCLBP compared with pain-free controls showing significance. Flexion relaxation was observed in both iliocostalis and thoracic erector spinae in the NSCLBP group but not controls. CONCLUSION: This study provides preliminary results. Differences with sitting posture are only seen when adolescents with NSCLBP are classified. Trunk muscle activation is not a sensitive marker for discriminating subgroups of NSCLBP during adolescence.

The influence of different sitting postures on head/neck posture and muscle activity.

To date the influence that specific sitting posture has on the head/neck posture and cervico-thoracic muscle activity has been insufficiently investigated. Therefore the aim of this study was to investigate whether three different thoraco-lumbar sitting postures affect head/neck posture and cervico-thoracic muscle activity. Twenty (10 men, 10 women) asymptomatic subjects were placed in 3 standardized thoraco-lumbar sitting postures (lumbo-pelvic, thoracic upright and slump) to investigate their influence on cervico-thoracic muscle activity and head/neck posture. There were significant differences in lumbar and thoracic curvatures in the 3 different sitting postures (P<0.002). Slump sitting was associated with greater head/neck flexion, anterior translation of the head (P<0.001) and increased muscle activity of cervical erector spinae (CES) compared to thoracic and lumbo-pelvic sitting (P=0.001). Thoracic upright sitting showed increased muscle activity of thoracic erector spinae (TES) compared to slump and lumbo-pelvic postures (P=0.015). Upper trapezius (UT) demonstrated no significant difference in muscle activation in the 3 sitting postures (P<0.991). This study demonstrates that different sitting postures affect head/neck posture and cervico-thoracic muscle activity. It highlights the potential importance of thoraco-lumbar spine postural adjustment when training head/neck posture.

An examination of the flexion-relaxation phenomenon in the cervical spine in lumbo-pelvic sitting.

The flexion-relaxation phenomenon (FRP) is well documented at end-range lumbar spine flexion in both standing and sitting however, the FRP has been insufficiently investigated in cervico-thoracic musculature. The aim of this study was to determine whether the FRP occurs during forward flexion of the neck, in lumbo-pelvic sitting, amongst a pain-free population. Surface electromyography (EMG) was used to measure muscle activation in 20 (10 men, 10 women) asymptomatic subjects in selected cervico-thoracic muscles during four, 5-s phases (upright posture, forward flexion, full flexion and return to upright) while subjects were positioned in lumbo-pelvic sitting. Spinal kinematics were simultaneously measured using an electromagnetic motion tracking device. No FRP was observed in upper trapezius or thoracic erector spinae (T4). When using visual methods to determine the presence/absence of the FRP, five subjects were believed to show evidence of the FRP in the cervical erector spinae. However, when using various non-visual criteria to determine the existence of the FRP, substantial variations (0-13 subjects) were evident. We recommend that criteria based upon relatively large differences in muscle activation should be considered when defining the FRP. These findings are of significance for future investigations examining specific cervical pain disorders.

Método para a correção da distorção de imagens obtidas por videofluoroscopia / Method for correction of distortions in images acquired by videofluoroscopy

OBJETIVO: Operacionalizar um protocolo para a correção de imagens obtidas por videofluoroscopia a partir de um modelo matemático descrito por Baltzopoulos (1995) e avaliar a magnitude do erro pelos métodos de calibração linear e não linear. MATERIAIS E MÉTODOS: As imagens foram obtidas por meio de um videofluoroscópio da marca Axion Siemens Iconos R100 de um indivíduo realizando exercício de extensão de joelho. Para a correção das imagens foi utilizado padrão de calibração não-linear. O processamento dos dados foi realizado em placa de captura da marca Silicon Graphics 320 e posteriormente analisado em um "software" Matlab. RESULTADOS: Para demonstrar a aplicabilidade do método foi avaliada a deformação do ligamento patelar. A utilização do padrão de calibração linear produziu um erro máximo de 0,086 mm, enquanto o padrão de calibração não linear atingiu um valor máximo de 0,019 mm. Já com relação ao erro médio, a calibração linear atingiu o valor de 0,024 mm, e a não linear apresentou um valor de 0,007 mm. CONCLUSÃO: Os resultados evidenciam a necessidade de utilização de um procedimento de calibração não linear.

OBJECTIVE: To implement a protocol for correction of images acquired by videofluoroscopy based on the mathematical model described by Baltzopoulos (1995) and to evaluate the magnitude of error in the linear and non-linear calibration methods. MATERIALS AND METHODS: The images were acquired using a Axion Siemens Iconos R100 videofluoroscope from one individual during knee extension exercise. A non-linear calibration pattern was used for the correction of the images. Data was processed using a Silicon Graphics 320 capture plate and subsequently analyzed using the Matlab software. RESULTS: In order to demonstrate the method's applicability, the deformation of the patellar ligament was evaluated. The use of a linear calibration pattern produced a maximum error of 0.086 mm, while the non-linear calibration pattern reached a maximum value of 0.019 mm. According to the mean error, the linear calibration was 0.024 mm, and the non-linear presented a value of 0.007 mm. CONCLUSION: The results show the need to use a non-linear calibration procedure.

Análise eletromiográfica do quadríceps durante a extensão do joelho em diferentes velocidades / Electromyographical analysis of the quadriceps during knee extension at different speeds

A síndrome de dor fêmuro-patelar (SDFP) é uma disfunção comum, geralmente causada por trações laterais excessivas da patela. Indivíduos com SDFP, usualmente apresentam inibição do vasto medial oblíquo (VMO), o qual é responsável pela tração medial patelar. O tratamento conservador envolve o reforço do quadríceps para promover melhor estabilidade e tração patelar. Muitos pesquisadores buscam o recrutamento seletivo do VMO, com o intuito de otimizar o tratamento. O objetivo deste estudo é investigar, através da eletromiografia, a interferência da velocidade angular e diferentes formas de fixação do tubo elástico na atividade quadricipital. Dez indivíduos do sexo masculino com ausência de lesão muscular ou articular participaram deste estudo. Indivíduos com ângulo Q fora do intervalo de 10-15° foram excluídos da pesquisa. O tubo elástico foi fixado paralelo e oblíquo em relação ao corpo do indivíduo. As extensões de joelho foram realizadas com velocidades angulares de 60 e 120°/seg. Nenhuma atividade seletiva do VMO foi encontrada. Comparando os níveis de atividade muscular, durante as duas velocidades angulares houve aumento no nível de atividade eletromiográfica em todas porções do quadríceps, apenas para a fixação do tubo elástico paralela. Os resultados sugerem uma atividade sinérgica entre o VMO e as outras porções do quadríceps.