The deflection of fatigued neck.

The human neck is a unique mechanical structure, highly flexible but fatigue prone. The rising prevalence of neck pain and chronic injuries has been attributed to increasing exposure to fatigue loading in activities such as prolonged sedentary work and overuse of electronic devices. However, a causal relationship between fatigue and musculoskeletal mechanical changes remains elusive. This work aimed to establish this relationship through a unique experiment design, inspired by a cantilever beam mechanical model of the neck, and an orchestrated deployment of advanced motion-force measurement technologies including dynamic stereo-radiographic imaging. As a group of 24 subjects performed sustained-till-exhaustion neck exertions in varied positions-neutral, extended, and flexed, their cervical spine musculoskeletal responses were measured. Data verified the occurrence of fatigue and revealed fatigue-induced neck deflection which increased cervical lordosis or kyphosis by 4-5° to 11°, depending on the neck position. This finding and its interpretations render a renewed understanding of muscle fatigue from a more unified motor control perspective as well as profound implications on neck pain and injury prevention.

Hip-spine parameters change with increasing age.

Aims: Spinopelvic pathology increases the risk for instability following total hip arthroplasty (THA), yet few studies have evaluated how pathology varies with age or sex. The aims of this study were: 1) to report differences in spinopelvic parameters with advancing age and between the sexes; and 2) to determine variation in the prevalence of THA instability risk factors with advancing age. Methods: A multicentre database with preoperative imaging for 15,830 THA patients was reviewed. Spinopelvic parameter measurements were made by experienced engineers, including anterior pelvic plane tilt (APPT), spinopelvic tilt (SPT), sacral slope (SS), lumbar lordosis (LL), and pelvic incidence (PI). Lumbar flexion (LF), sagittal spinal deformity, and hip user index (HUI) were calculated using parameter measurements. Results: With advancing age, patients demonstrate increased posterior APPT, decreased standing LL, decreased LF, higher pelvic incidence minus lumbar lordosis (PI-LL) mismatch, higher prevalence of abnormal spinopelvic mobility, and higher HUI percentage. With each decade, APPT progressed posteriorly 2.1°, LF declined 6.0°, PI-LL mismatch increased 2.9°, and spinopelvic mobility increased 3.8°. Significant differences were found between the sexes for APPT, SPT, SS, LL, and LF, but were not felt to be clinically relevant. Conclusion: With advancing age, spinopelvic biomechanics demonstrate decreased spinal mobility and increased pelvic/hip mobility. Surgeons should consider the higher prevalence of instability risk factors in elderly patients and anticipate changes evolving in spinopelvic biomechanics for young patients.

A comparison of visual and direct assessments of lumbar spine posture.

BACKGROUND: Posture is assessed clinically and used to guide treatment of low back pain. Collectively, the relevance of posture and clinical postural assessments have come under scrutiny. This study aimed to determine (a) the intra-rater and inter-rater reliability of visual assessments of lumbar lordosis, and (b) the agreement between visual and direct postural assessments. METHODS: Ten physiotherapists visually assessed the lumbar lordosis from 3D scans of 50 asymptomatic participants, and 15 duplicates, using a grading scale of deviations (range: 0 = normal to 3 = severe). Lumbar lordosis angle was directly assessed using the Vitus Smart 3D whole body scanner. Cohen's Kappa was used to determine the intra-rater and inter-rater reliability of visual assessments, with polyserial correlation (ps) used to determine the agreement between visual and direct assessments. RESULTS: Overall, 93% and 83% of all intra-rater and inter-rater differences in visual assessments were within a single grade point, respectively. The intra-rater and inter-rater reliability of visual assessments was moderate (κ (95%CI): 0.56 (0.45, 0.67)) and slight (κ (95%CI): 0.13 (0.08, 0.19)), respectively. The agreement between visual and direct assessments was moderate (ps = -0.41, p = 0.04). CONCLUSION: Visual assessments of lumbar posture demonstrated moderate repeatability and agreement with quantitative assessments. While agreement between assessors was slight, 83% of the visual ratings were within a single grade point, suggesting greater coherence among clinicians than our statistics suggested. As with any clinical assessments involving uncertainty, postural assessment should not solely guide treatment.

Change of cervical flexion range of motion influences postoperative sagittal alignment of the cervical spine after laminoplasty.

OBJECTIVE: The relationships between preoperative cervical spine range of motion (ROM) and postoperative cervical sagittal alignment (CSA), and clinical outcomes after laminoplasty (LMP) have been widely studied. However, the impact of ROM changes on postoperative CSA and clinical outcomes after LMP remains unclear. Herein, patients with cervical spondylotic myelopathy (CSM) were retrospectively analyzed to explore the association between postoperative cervical ROM changes and CSA and surgical outcomes. METHODS: Patients who underwent cervical LMP at our hospital between January 2019 to June 2022 were retrospectively reviewed. CSA parameters were measured before the surgery and at the final follow-up. Loss of cervical lordosis (LCL) was defined as preoperative cervical lordosis (CL) - postoperative CL. An increase in the cervical sagittal vertical axis (I-cSVA) was defined as postoperative cervical sagittal vertical axis (cSVA) - preoperative cSVA. We defined the changes in cervical flexion range of motion (△Flex ROM, preoperative Flex ROM minus postoperative Flex ROM) > 10° as L- Flex ROM group, and △Flex ROM ≤ 10° as S- Flex ROM group. Japanese Orthopedic Association (JOA) score and visual analog score (VAS) were used to assess the surgical outcomes. RESULTS: The study comprised 74 patients and the average follow-up period was 31.83 months. CL, total ROM, and Flex ROM decreased and cSVA increased after cervical LMP. LCL and I-cSVA were positively correlated with △Flex. Multiple linear regression analysis showed that a decrease in the Flex ROM was a risk factor for LCL and I-cSVA after LMP. LCL and I-cSVA were higher in the L-Flex ROM group than in the S-Flex ROM group. Postoperative JOA and the JOA recovery rate were worse in the L-Flex ROM group than in the S-Flex ROM group. CONCLUSIONS: Cervical total and Flex ROM decreased after cervical LMP. The reduction of Flex ROM was associated with LCL and I-cSVA after surgery. The preservation of cervical Flex ROM helps maintain CSA after LMP. Therefore, more attention should be paid to maintaining cervical ROM to obtain good CSA and surgical effects after cervical LMP.

Sagittal spinal curvatures of young adults in the context of their self-reported physical activity and somatic parameters.

The objective of this study was to assess the thoracic kyphosis (ThKA) and lumbar lordosis (LLA) in healthy young adults and to investigate potential relationships between spinal curvatures, self-reported physical activity (PA), and somatic parameters. The study included 380 female students and 211 male students aged 20.7 ± 1.5 years. The ThKA and LLA were measured using a Plurimeter-V gravity inclinometer. The level of PA was estimated using the International Physical Activity Questionnaire. ThKA was lower in women compared to men, while LLA was higher in women than in men (p < 0.0001). Female students reported lower PA than male students (p < 0.001). Female students with ThKA within normal values reported a significantly higher amount of low-intensity PA compared to those with ThKA below or above the norm. A correlation was found between ThKA and body mass index (BMI), body adiposity index (BAI), WC, and fat percentage (rho < 0.2), whereas LLA showed correlations with BMI, BAI, waist circumference, and fat percentage (rho < 0.2). Among male students, a correlation was found between LLA and BMI as well as WC (rho < 0.2). Maintaining a healthy body composition may be instrumental in mitigating the risk of developing spinal curvature abnormalities.

Gender differences in spinal mobility during postural changes: a detailed analysis using upright CT.

Lumbar spinal alignment is crucial for spine biomechanics and is linked to various spinal pathologies. However, limited research has explored gender-specific differences using CT scans. The objective was to evaluate and compare lumbar spinal alignment between standing and sitting CT in healthy individuals, focusing on gender differences. 24 young and 25 elderly males (M) and females (F) underwent standing and sitting CT scans to assess lumbar spinal alignment. Parameters measured and compared between genders included lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), lordotic angle (LA), foraminal height (FH), and bony boundary area (BBA). Females showed significantly larger changes in SS and PT when transitioning from standing to sitting (p = .044, p = .038). A notable gender difference was also observed in the L4-S LA among the elderly, with females showing a significantly larger decrease in lordotic angle compared to males (- 14.1° vs. - 9.2°, p = .039*). Females consistently exhibited larger FH and BBA values, particularly in lower lumbar segments, which was more prominent in the elderly group (M vs. F: L4/5 BBA 80.1 mm2 [46.3, 97.8] vs. 109.7 mm2 [74.4, 121.3], p = .019 in sitting). These findings underline distinct gender-related variations in lumbar alignment and flexibility, with a focus on noteworthy changes in BBA and FH in females. Gender differences in lumbar spinal alignment were evident, with females displaying greater pelvic and sacral mobility. Considering gender-specific characteristics is crucial for assessing spinal alignment and understanding spinal pathologies. These findings contribute to our understanding of lumbar spinal alignment and have implications for gender-specific spinal conditions and treatments.

Is spinopelvic compensation associated with unstable gait?: Analysis using whole spine X-rays and a two-point accelerometer during gait in healthy adults.

BACKGROUND: Pelvic incidence (PI)-lumbar lordosis (LL) mismatch has a significant destabilizing effect on the center of gravity sway in the static standing position. However, the association between spinopelvic alignment and balance during gait in healthy volunteers is poorly understood. RESEARCH QUESTION: The degree of PI-LL mismatch and trunk anterior tilt in the static standing posture influences dynamic balance during gait. METHODS: In this study, 131 healthy volunteers were divided into two groups: harmonious group (PI - LL ≤ 10°; n = 91) and unharmonious group (PI - LL > 10°; n = 40). A two-point accelerometer system was used for gait analysis; accelerometers were attached to the pelvis and upper trunk to measure acceleration in the forward-backward, right-left, and vertical directions so that sagittal (front-back) deviation width, coronal (right-left) width, and vertical width and their ratios were calculated. Measurements were compared between the two groups, and correlations between alignment and accelerometer data were examined. RESULTS: The harmonious group showed a negative correlation between pelvic sagittal width and PI - LL, pelvic tilt (PT), and sagittal vertical axis (SVA) (correlation coefficient ρ = -0.42, -0.38, and -0.4, respectively), and a positive correlation between sagittal ratio and PI - LL (ρ = 0.35). The unharmonious group showed a positive correlation between pelvic sagittal width and PI and PT (ρ = 0.43 and 0.33, respectively) and between sagittal ratio and SVA (ρ = 0.32). The unharmonious group showed a positive correlation between upper trunk sagittal width and PI - LL and PT (ρ = 0.38 and 0.36, respectively). SIGNIFICANCE: The association between spinal alignment and gait parameters differs depending on the presence or absence of PI-LL mismatch. The degree of pelvic compensation and trunk anterior tilt during static standing were associated with unstable gait balance.

Quantitatively assessing the effect of cervical sagittal alignment on dynamic intervertebral kinematics by video-fluoroscopy technique.

BACKGROUND: Cervical sagittal alignment is crucial for distributing the head load to lower cervical segments and maintaining normal cervical spine function, but its biomechanical effect on the cervical spine was not fully elucidated. OBJECTIVE: To investigate the effect of cervical sagittal alignment on dynamic intervertebral kinematics. DESIGN: Cross-sectional study. METHODS: Healthy participants without neck pain were recruited and divided into lordosis, straight and kyphosis groups according to the C2-C7 Cobb angle at the neutral position. The anti-directional and total joint motions were extracted across 10 epochs of dynamic cervical flexion and extension movements. RESULTS: /findings: The overall anti-directional joint motion during flexion is larger in the kyphosis group when compared with the lordosis group (p = 0.021), while the range of flexion is smaller in the kyphosis group than that in the lordosis group (p = 0.017). The C2/C3 anti-directional joint motion during extension in the straight group is larger than that in the lordosis group (p = 0016). The range of extension in the kyphosis group (p < 0.001) and the straight group (p = 0.002) are larger than that in the lordosis group. The increased range of extension in the kyphosis and straight groups were mainly from the C3/C4, C4/C5, and C5/C6 joints(p < 0.05). CONCLUSION: Changes in cervical sagittal alignment alter both the quality and quantity of the individual joint motions. More adjustments are required by the cervical joints to complete neck movements with the loss of lordosis. The lordotic curvature is a relatively effort-saving mode for the cervical spine from a biomechanical perspective.

Prolonged Standing-Induced Low Back Pain Is Linked to Extended Lumbar Spine Postures: A Study Linking Lumped Lumbar Spine Passive Stiffness to Standing Posture.

Postural assessments of the lumbar spine lack valuable information about its properties. The purpose of this study was to assess neutral zone (NZ) characteristics via in vivo lumbar spine passive stiffness and relate NZ characteristics to standing lumbar lordosis. A comparison was made between those that develop low back pain during prolonged standing (pain developers) and those that do not (nonpain developers). Twenty-two participants with known pain status stood on level ground, and median lumbar lordosis angle was calculated. Participants were then placed in a near-frictionless jig to characterize their passive stiffness curve and location of their NZ. Overall, both pain developers and nonpain developers stood with a lumbar lordosis angle that was more extended than their NZ boundary. Pain developers stood slightly more extended (in comparison to nonpain developers) and had a lower moment corresponding to the location of their extension NZ boundary. Overall, in comparison to nonpain developers, pain developers displayed a lower moment corresponding to the location of their extension NZ boundary which could correspond to greater laxity in the lumbar spine. This may indicate why pain developers have a tendency to stand further beyond their NZ with greater muscle co-contraction.

Stronger association of objective physical metrics with baseline patient-reported outcome measures than preoperative standing sagittal parameters for adult spinal deformity patients.

OBJECTIVE: Sagittal alignment measured on standing radiography remains a fundamental component of surgical planning for adult spinal deformity (ASD). However, the relationship between classic sagittal alignment parameters and objective metrics, such as walking time (WT) and grip strength (GS), remains unknown. The objective of this work was to determine if ASD patients with worse baseline sagittal malalignment have worse objective physical metrics and if those metrics have a stronger relationship to patient-reported outcome metrics (PROMs) than standing alignment. METHODS: The authors conducted a retrospective review of a multicenter ASD cohort. ASD patients underwent baseline testing with the timed up-and-go 6-m walk test (seconds) and for GS (pounds). Baseline PROMs were surveyed, including Oswestry Disability Index (ODI), Patient-Reported Outcomes Measurement Information System (PROMIS), Scoliosis Research Society (SRS)-22r, and Veterans RAND 12 (VR-12) scores. Standard spinopelvic measurements were obtained (sagittal vertical axis [SVA], pelvic tilt [PT], and mismatch between pelvic incidence and lumbar lordosis [PI-LL], and SRS-Schwab ASD classification). Univariate and multivariable linear regression modeling was performed to interrogate associations between objective physical metrics, sagittal parameters, and PROMs. RESULTS: In total, 494 patients were included, with mean ± SD age 61 ± 14 years, and 68% were female. Average WT was 11.2 ± 6.1 seconds and average GS was 56.6 ± 24.9 lbs. With increasing PT, PI-LL, and SVA quartiles, WT significantly increased (p < 0.05). SRS-Schwab type N patients demonstrated a significantly longer average WT (12.5 ± 6.2 seconds), and type T patients had a significantly shorter WT time (7.9 ± 2.7 seconds, p = 0.03). With increasing PT quartiles, GS significantly decreased (p < 0.05). SRS-Schwab type T patients had a significantly higher average GS (68.8 ± 27.8 lbs), and type L patients had a significantly lower average GS (51.6 ± 20.4 lbs, p = 0.03). In the frailty-adjusted multivariable linear regression analyses, WT was more strongly associated with PROMs than sagittal parameters. GS was more strongly associated with ODI and PROMIS Physical Function scores. CONCLUSIONS: The authors observed that increasing baseline sagittal malalignment is associated with slower WT, and possibly weaker GS, in ASD patients. WT has a stronger relationship to PROMs than standing alignment parameters. Objective physical metrics likely offer added value to standard spinopelvic measurements in ASD evaluation and surgical planning.

Avaliação da lordose lombar e sua relação com a dor lombopélvica em gestantes / Evaluation of lumbar lordosis and its relation to the lumbopelvic pain in pregnants

O objetivo deste trabalho foi avaliar a magnitude da lordose lombar, sua influência na dor lombopélvica e a qualidade de vida em gestantes. Para tal, foi realizado um estudo com 20 mulheres não gestantes (C) e 13 gestantes ao longo dos trimestres gestacionais (G1, G2 e G3). Todas as mulheres foram submetidas à avaliação inicial para registro dos dados pessoais, hábitos de vida, antecedentes pessoais, uso de medicamentos, história ginecológica e obstétrica. Posteriormente, as voluntárias do grupo controle foram avaliadas uma vez e as gestantes foram avaliadas em três momentos distintos, no 10, 20 e 30 trimestres gestacionais. A avaliação do grau de lordose lombar foi realizada por meio de técnica fotogramétrica; a avaliação de locais de dor, o tipo de dor e sua intensidade foram feitas por meio do Questionário McGill de dor; e a avaliação da qualidade de vida foi feita pelo Questionário WHOQOL-bref. Neste trabalho, não foi possível observar padrão de alteração da curvatura lombar no decorrer da gestação. Também não foi observada relação entre a curvatura lombar e a dor lombopélvica relacionada à gestação.

The purpose of this study was to evaluate the magnitude of lumbar lordosis, its influence on lumbopelvic pain and quality of life in pregnant women. To this end, a study was done with 20 non-pregnant women (C) and 13 pregnant women during the trimesters of pregnancy (G1, G2 and G3). All women underwent initial assessment for registration of personal data, lifestyle, personal history, medications, gynecological and obstetric history. Later, the volunteers in the control group were evaluated once and pregnant women were evaluated at three different times, the first, second and third trimesters of pregnancy. The evaluation of the degree of lumbar lordosis was performed by a photogrammetric technique. The assessment of points/places of pain, the kind of pain and its intensity were made by McGill Pain Questionnaire, and the quality of life assessment was made by WHOQOL-bref. In this study, it was not possible to observe a pattern of change in lumbar curvature during pregnancy. There was also no relationship between lumbar curvature and lumbopelvic pain related to pregnancy.

Incidencia y factores de riesgo de degeneración de los discos límites a una fusión lumbar / Incidence and risk factors of adjacent disc degeneration after lumbar fusion

Objetivo. Determinar la incidencia y analizar los posibles factores de riesgo de desarrollar una degeneración del disco adyacente después de una artrodesis lumbar instrumentada. Material y método. Estudio retrospectivo consecutivo de 230 pacientes con patología degenerativa lumbar, tratados entre los años 1990 y 2000 mediante una artrodesis instrumentada posteroexterna lumbar o lumbosacra. Se ha valorado la afectación del disco adyacente, mediante un criterio radiológico con RX y RM, y se han analizado los siguientes factores de riesgo: la edad, el sexo, el número de niveles instrumentados, el estado del disco límite previo a la cirugía, la lordosis del segmento instrumentado y la lordosis lumbosacra, y la sagitalización de las facetas articulares del disco límite. Resultados. Hemos observado 41 pacientes (17,82%) afectos de síndrome del disco adyacente, con un seguimiento medio de 8,5 años. La edad media fue de 59 años con predominio del sexo femenino. La fusión L5-S1 presenta menos incidencia de afectación del disco límite (p<0,05). Se afectó mayoritariamente el disco adyacente proximal en 36 pacientes (87,8%) y 19 pacientes (46%) requirió cirugía. El tiempo medio hasta el diagnóstico del disco adyacente radiológico ha sido de 6,1 años. Conclusiones. Existe un riesgo del 17,82% (41 pacientes) de presentar disco adyacente radiológico a los 6 años después de la primera cirugía con un riesgo de 6,26% (19 pacientes) de ser intervenido. El sexo, el número de niveles fusionados y la fusión hasta el sacro han sido los principales factores de riesgo (AU)

Objective. The aim of this retrospective study is to determine the incidence, the rate of adjacent disc degeneration (ADD) and to analyse the major risk factors after instrumented lumbar fusion. Materials and methods. Retrospective consecutive study of 230 patients, with lumbar degenerative disease, who underwent lumbar or lumbosacral instrumented spine fusion between 1990 and 2000. We used radiographic criteria (X-RAY and MRI) in order to determine ADD, and we analysed the following risk factors: age, gender, number of levels fused, adjacent disc status before surgery, segmental lordosis and lumbosacral lordosis, and finally, the facet joint angle of adjacent disc. Results. ADD was found in 41 (17.82%) patients, the mean follow-up period was 8.5years. The average age was 59years with female predominance. L5-S1 fusion showed a significant (P<.05) lower risk for developing degenerative changes at the adjacent segments than any other fusions. The cranial level of the fused segment was mainly affected in 36 (87.8%) patients and 19 (46%) patients required surgery. The average interval from surgery to the development of ADD was 6.1years. Conclusions. There is a risk of 17.82% (41 patients) of being affected by radiographic ADD in an average of 6years after the first surgery, with a risk of 6.26% (19 patients) of having surgery. The gender, number of levels fused and fusion to the sacrum were the main risk factors (AU)

Estudo experimental do sequenciamento das manobras da ligamentotaxia na descompressão do canal vertebral / Experimental study of ligamentotaxis maneuvers sequencing in vertebral canal decompression

A descompressão do canal vertebral, para aliviar as estruturas nervosas, pode ser realizada por meio da ligamentotaxia. O objetivo foi analisar a influência da seqüência de realização da ligamentotaxia sobre a descompressão do canal vertebral. Foram utilizados segmentos de vértebras de suínos (Landrace). Um equipamento especialmente desenvolvido foi utilizado para produção de fratura do tipo explosão. Após a tomografia computadorizada, 10 espécimes que melhores apresentavam fraturas do tipo explosão foram fixados com fixador interno (Synthes). Foram formados dois grupos. No primeiro (n=5) foi realizada a lordose e depois a distração. Posteriormente, foram submetidos à nova compressão por meio de morsa até o retorno da fratura à posição inicial, a seguir foram novamente submetidos à distração e lordose. No segundo grupo (n=5) foi realizada a distração e depois a lordose. Após cada manobra era realizado o exame tomográfico para medir o diâmetro do canal vertebral. Os deslocamentos dos fragmentos dos corpos vertebrais fraturados foram mensurados e comparados utilizando t de Student (p<0,05). Comparando os deslocamentos entre os grupos, não foram observadas diferenças estatísticas (p<0,06). Esse resultado é próximo ao nível de significância adotado, sugerindo uma forte tendência que demonstra a eficácia superior da manobra iniciada pela realização da lordose.

Vertebral canal decompression, intended to provide relief to nervous structures, may be performed by means of legamentotaxis. The objective of this study was to assess the influence of the ligamentotaxis sequence on vertebral canal decompression. Vertebral segments of Landrace swine specimens were used. A device especially developed for producing a burst-type fracture was employed. Subsequently to the computerized tomography scan, 10 specimens that best showed a burst-type fracture were fixated with internal fixator (Synthes). Two groups were formed. On the first group (n=5), lordosis followed by distraction were performed. Then, they were submitted to distraction and lordosis. On the second group (n=5), distraction was provided first, and then lordosis was performed. After each maneuver, vertebral canal was measured by tomography scan. Fractured vertebral body fragments were measured and compared using the Student's t test (p<0,05). By comparing dislocations between groups, no statistical differences were found (p<0,06). This result is close to the significance level adopted, suggesting a strong trend towards a better effectiveness of the maneuver started with lordosis.

Radiographic evaluation of cervical spine of subjects with temporomandibular joint internal disorder

Apesar de a etiofisiopatologia dos distúrbios internos (DI) da articulação temporomandibular (ATM) ser ainda desconhecida, sugere-se que as posturas de cabeça e corpo estariam associadas a seu desencadeamento, desenvolvimento e sua perpetuação. O objetivo deste estudo foi verificar a relação entre alterações radiográficas de coluna cervical e distúrbios internos da ATM. Este estudo avaliou 30 indivíduos com distúrbios da ATM (grupo teste) e 20 saudáveis (grupo controle). Os indivíduos submeteram-se à avaliação clínica e radiográfica. A avaliação clínica consistiu de anamnese e exame físico do sistema estomatognático. A avaliação radiográfica consistiu de análise de radiografias laterais de coluna cervical por fisioterapeutas e traçados. O grupo teste apresentou o dobro da prevalência de hiperlordose de coluna cervical (20,7% versus 10,5%) e quase a metade (41,4% versus 79,0%) de retificação (p = 0,03). Em um segundo momento, o grupo teste foi subdividido em três subgrupos em função da gravidade clínica da disfunção temporomandibular, avaliada pelo índice de Helkimo. Não houve diferença estatisticamente significante entre os subgrupos, mas se constatou uma tendência do subgrupo com disfunção grave a apresentar prevalência de hiperlordose cervical. Esses resultados sugerem uma tendência dos indivíduos com disfunção temporomandibular (DTM) grave a apresentarem hiperlordose. No entanto, futuros estudos devem ser feitos, analisando-se um maior número de indivíduos portadores de DTM grave para corroborar nossos achados.

Estudio de la postura sedente en una población infantil / Study of the position in a children population

Introducción: El estudio describe la postura sedente que adopta una población infantil durante el periodo de atención al profesor, el cuál comprende la mayor parte del tiempo de las clases en el colegio. Material y método: Se elige al azar una población escolar perteneciente a un colegio público de la ciudad de Salamanca y se observa, de una forma directa, su postura sedente durante el periodo de atención al profesor. Se rellena una ficha para cada sujeto que contiene diferentes parámetros de la postura sedente: tipo de postura, posición de la columna vertebral, apoyo de los pies en el suelo, cruce de piernas y pies, apoyo en el asiento, utilización del respaldo, flexión de rodilla, apoyo asimétrico sobre la mesa, rotación del tronco y posición del cuello. Se realiza un análisis estadístico de los datos comparando la postura sedente que adoptan los sujetos en cada uno de los cursos estudiados y en función del género. Resultados: Los sujetos estudiados son 68 pertenecientes a los cursos de 3.º, 4.º, 5.º y 6.º de primaria, con edades comprendidas entre los 8 años y 7 meses y los 12 años y 7 meses siendo la media 10,38 ñ 1,244, el 48,5 por ciento de ellos niños y el 51,5 por ciento niñas. La postura sedente adoptada con mayores porcentajes es la siguiente: postura sedente media (54,4 por ciento), posición flexionada de la columna vertebral (55,9 por ciento), apoyo de la planta del pie en el suelo (50 por ciento), pies cruzados (55,8 por ciento), apoyo al fondo del asiento (63,2 por ciento), piernas sin cruzar (92,6 por ciento), no utilización del respaldo (47,1 por ciento)-uso correcto del respaldo (41,2 por ciento), flexión de rodillas de más de 90 grados (38,2 por ciento), apoyo de ambos codos sobre la mesa (55,9 por ciento), no rotación del tronco al escribir (52,9 por ciento) y flexión de la columna cervical (42,6 por ciento). Conclusiones: Los niños en edad escolar estudiados no adoptan la postura sedente correcta y recomendada por numerosos autores. Aparecen diferencias en la postura sedente de los niños de la misma clase y entre los diferentes cursos lo que sin duda está en relación con las dimensiones del mobiliario utilizado (AU)