ABSTRACT
INTRODUCCIÓN: La mayoría de los establecimientos educacionales tienen una jornada escolar completa, generando que el estudiante transporte mayor cantidad de útiles escolares en su mochila. OBJETIVO: Analizar el peso promedio de las mochilas de espalda en estudiantes de educación básica de la comuna de Copiapó. METODOLOGÍA: se realizó un estudio descriptivo de corte transversal con alcance correlacional, la muestra estuvo constituida por 286 estudiantes (139 varones y 147 mujeres) de educación básica, de un establecimiento escolar de la comuna de Copiapó. Se analizó el peso corporal, la altura y el peso de las mochilas durante una semana, mediante una plataforma de fuerza y estadiómetro. RESULTADOS: Se encontró que entre los días lunes a jueves los estudiantes llevaban en su mochila un peso que sobrepasaba el 10/ de su peso corporal. Asimismo, las mochilas de espaldas son las más utilizadas en comparación con las mochilas con ruedas, con un 88,1% de la muestra. Sin embargo, las mochilas de espalda presentaron menor peso al compararlas con las mochilas con ruedas, las cuales tuvieron valores cercanos al 20% del peso corporal. CONCLUSIÓN: La mayoría de los estudiantes transportaban en sus mochilas, pesos que superan el 10% de peso recomendado, siendo las mochilas con rueda las de mayor peso. Se recomienda desarrollar normas establecidas dentro de los colegios, para evitar el traslado de dichas cargas y prevenir alteraciones posturales, biomecánicas y fisiológicas.
INTRODUCTION: Most educational establishments have a full school day, causing the student to carry a greater number of school supplies in their backpack. OBJECTIVE: To analyze the average weight of backpacks in basic education students of the Copiapó district. METHODOLOGY: a descriptive cross-sectional study with correlational scope was carried out, the sample consisted of 286 students (139 men and 147 women) of basic education, from a school in the district of Copiapó. Body weight, height and backpack weight were analyzed for one week, using a force platform and stadiometer. RESULTS: It was found that between Monday and Thursday the students carried a weight in their backpack that exceeded 10% of their body weight. Likewise, backpacks on the back are the most used compared to backpacks with wheels, with 88.1% of the sample. However, the backpacks presented less weight when compared to the backpacks with wheels, which had values close to 20% of body weight. CONCLUSION: Most of the students carried weights in their backpacks that exceed 10% of the recommended weight, with wheeled backpacks being the heaviest. It is recommended to develop established norms within the schools, to avoid the transfer of said loads and prevent postural, biomechanical and physiological alterations.
Subject(s)
Humans , Male , Female , Child , Students , Weight Lifting/physiology , Lifting , Body Weight , Chile , Cross-Sectional StudiesABSTRACT
BACKGROUND: Stemless anatomic total shoulder arthroplasty (TSA) has been gaining significant popularity but poses unique challenges for subscapularis repair. Tenotomy with side-to-side repair has been the most frequently reported technique for subscapularis repair with stemless TSA but has the poorest biomechanical properties, and clinical failures have been reported. There is limited biomechanical evidence evaluating other subscapularis repair techniques for stemless TSA. Therefore, the goal of this study was to investigate 2 additional techniques using a subscapularis peel for subscapularis repair with a stemless TSA. METHODS: We used 18 male cadaveric specimens to investigate the native subscapularis (n = 6) and 2 subscapularis repair techniques (n = 12) after stemless anatomic TSA (Eclipse). A subscapularis peel with double-row, knotless anchor-based repair (n = 6) was compared with a subscapularis peel with a "backpack" repair (n = 6). The specimens then underwent biomechanical testing, including cyclic displacement and load-to-failure testing. The mode of failure was also recorded. RESULTS: The native tendon had the highest ultimate load to failure (mean, 1017.1 N). Load to failure was similar between the 2 study groups: 397.9 N for the peel and backpack repair and 593.7 N for the knotless anchor-based repair (P > .05 for all comparisons). Moreover, no significant differences in cyclic displacement or construct stiffness were found between the groups (P > .05 for all comparisons). CONCLUSIONS: A double-row, knotless anchor-based repair of a subscapularis peel for stemless anatomic shoulder arthroplasty has similar biomechanical properties to a backpack repair technique; however, both techniques fail to reproduce the native biomechanical properties at time zero.
Subject(s)
Arthroplasty, Replacement, Shoulder , Shoulder Joint , Biomechanical Phenomena , Cadaver , Humans , Male , Osteotomy , Rotator Cuff/surgery , Shoulder Joint/surgery , Suture Anchors , Suture TechniquesABSTRACT
BACKGROUND: Wearing a school backpack every day may cause postural problems and affect the gait pattern of children and adolescents. The aim of the present study was to analyze the influence of a 4â¯kg backpack load on the gait pattern and postural sway. OBJECTIVES: The aim of the present study was to analyze the influence of a backpack load of 4 kg on the gait and postural sway of elementary school children. MATERIAL AND METHODS: In this prospective study, a group of 12 elementary school children aged between 7 and 10 years without neurological or orthopedic problems participated. The measurements included a clinical examination, three-dimensional gait analysis with electromyographic recordings and measurement of postural sway on a force plate. RESULTS: The backpack load, on average 15% of the body weight, led to a slower walking speed, shorter step length and increased double-support phase. Increased anterior pelvic and trunk tilt, as well as hip flexion were also observed. Furthermore, the muscle activity and postural sway of the children were affected by the increased load. CONCLUSIONS: School backpacks weighing 4â¯kg caused changes in gait, muscle activity, posture and stability in elementary school children. Due to the weight of the backpack, the centre of mass shifted backwards and the children became less stable. During gait, this was compensated by increased anterior pelvic and trunk tilt and increased hip flexion. The activity of the paraspinal muscles was decreased and indicates that the backpack is carried passively. This may cause a negative long-term effect.
