Ivan Silveira de Avelar

Back Pain Prevalence and Its Associated Factors in Brazilian Athletes from Public High Schools: A Cross-Sectional Study

Most studies on the prevalence of back pain have evaluated it in developed countries (Human Development Index—HDI > 0.808), and their conclusions may not hold for developing countries. The aim of this study was to identify the prevalence of back pain in representative Brazilian athletes from public high schools. This cross-sectional study was performed during the state phase of the 2015 Jogos dos Institutos Federais (JIF), or Federal Institutes Games, in Brazil (HDI = 0.744), and it enrolled 251 athletes, 173 males and 78 females (14–20 years old). The dependent variable was back pain, and the independent variables were demographic, socioeconomic, psychosocial, hereditary, exercise-level, anthropometric, strength, behavioral, and postural factors. The prevalence ratio (PR) was calculated using multivariable analysis according to the Poisson regression model (α = 0.05). The prevalence of back pain in the three months prior to the study was 43.7% (n = 104), and 26% of the athletes reported feeling back pain only once. Multivariable analysis showed that back pain was associated with demographic (sex), psychosocial (loneliness and loss of sleep in the previous year), hereditary (ethnicity, parental back pain), strength (lumbar and hand forces), anthropometric (body mass index), behavioral (sleeping time per night, reading and studying in bed, smoking habits in the previous month), and postural (sitting posture while writing, while on a bench, and while using a computer) variables. Participants who recorded higher levels of lumbar and manual forces reported a lower prevalence of back pain (PR < 0.79), whereas feeling lonely in the previous year, obesity, and ethnicity exhibited the highest prevalence ratio (PR > 1.30). In conclusion, there is no association between exercise levels and back pain but there is an association between back pain and non-exercise related variables.

Body composition of chronic renal patients: anthropometry and bioimpedance vector analysis

OBJECTIVE to compare the body composition of patients undergoing hemodialysis with that of healthy individuals using different methods. METHOD cross-sectional study assessing male individuals using anthropometric markers, electrical bioimpedance and vector analysis. RESULTS the healthy individuals presented larger triceps skinfold and arm circumference (p<0.001). The bioimpedance variables also presented significant higher values in this group. Significant difference was found in the confidence interval of the vector analysis performed for both the patients and healthy individuals (p<0.0001). The tolerance intervals showed that 55.20% of the patients were dehydrated, 10.30% presented visible edema, and 34.50% were within normal levels of hydration. Bioimpedance and vector analysis revealed that 52% of the patients presented decreased cell mass while 14.00% presented increased cell mass. CONCLUSIONS the differences in the body composition of patients and healthy individuals were revealed through bioimpedance and vector analysis but not through their measures of arm circumference and arm muscle area.OBJETIVO: comparar a composicao corporal de pacientes em hemodialise com sujeitos saudaveis, por diferentes metodos de avaliacao. METODOS: estudo transversal realizado com sujeitos do sexo masculino com avaliacoes antropometricas, bioimpedância eletrica e analise vetorial. RESULTADOS: a prega cutânea tricipital e a circunferencia de braco foram maiores (p<0,001) nos sujeitos saudaveis. As variaveis da bioimpedância, tambem, tiveram valores maiores e significativos nesse grupo. O intervalo de confianca da analise vetorial dos pacientes e sujeitos saudaveis mostrou diferenca significativa (p<0,0001). Os intervalos de tolerância para hidratacao revelaram que 55,20% dos pacientes estavam desidratados; 10,30% com edema aparente e 34,50% com hidratacao normal. A bioimpedância e a analise vetorial determinaram que 52% dos pacientes tinham reducao e 14% aumento da massa celular. CONCLUSOES: as diferencas na composicao corporal entre pacientes e sujeitos saudaveis foram demonstradas por meio da bioimpedância e analise vetorial, mas, nao pelas medidas da circunferencia e da area muscular de braco.

Evaluation of factors associated with severe and frequent back pain in high school athletes

Several studies have shown that half of all young athletes experience back pain (BP). However, high intensity and frequency of BP may be harmful, and the factors associated with BP severity have not been investigated in detail. Here, we investigated the factors associated with a high intensity and high frequency of BP in high school athletes. We included 251 athletes (173 boys and 78 girls [14–20 years old]) in this cross-sectional study. The dependent variables were a high frequency and high intensity of BP, and the independent variables were demographic, socioeconomic, psychosocial, hereditary, anthropometric, behavioural, and postural factors and the level of exercise. The effect measure is presented as prevalence ratio (PR) with 95% confidence interval (CI). Of 251 athletes, 104 reported BP; thus, only these athletes were included in the present analysis. Results of multivariable analysis showed an association between high BP intensity and time spent using a computer (PR: 1.15, CI: 1.01–1.33), posture while writing (PR: 1.41, CI: 1.27–1.58), and posture while using a computer (PR: 1.39, CI: 1.26–1.54). Multivariable analysis also revealed an association of high BP frequency with studying in bed (PR: 1.19, CI: 1.01–1.40) and the method of carrying a backpack (PR: 1.19, CI: 1.01–1.40). In conclusion, we found that behavioural and postural factors are associated with a high intensity and frequency of BP. To the best of our knowledge, this study is the first to compare different intensities and frequencies of BP, and our results may help physicians and coaches to better understand BP in high school athletes.

Use of a backpack alters gait initiation of high school students

We assessed how backpack carriage influences the gait initiation (GI) process in high school students, who extensively use backpacks. GI involves different dynamics from gait itself, while the excessive use of backpacks can result in adverse effects. 117 high school students were evaluated in three experimental conditions: no backpack (NB), bilateral backpack (BB), and unilateral backpack (UB). Two force plates were used to acquire ground reaction forces (GRFs) and moments for each foot separately. Center of pressure (COP) scalar variables were extracted, and statistical parametric mapping analysis was performed over the entire COP/GRFs time series. GI anticipatory postural adjustments (APAs) were reduced and were faster in backpack conditions; medial-lateral COP excursion was smaller in this phase. The uneven distribution of the extra load in the UB condition led to a larger medial-lateral COP shift in the support-foot unloading phase, with a corresponding vertical GRF change that suggests a more pronounced unloading swing foot/loading support foot mechanism. The anterior-posterior GRFs were altered, but the COP was not. A possible explanation for these results may be the forward trunk lean and the center of mass proximity of the base of support boundary, which induced smaller and faster APA, increased swing foot/support foot weight transfer, and increased load transfer to the first step.

Composición corporal de pacientes renales crónicos en hemodiálisis: antropometría y análisis vectorial por impedancia bioeléctrica

OBJECTIVE to compare the body composition of patients undergoing hemodialysis with that of healthy individuals using different methods. METHOD cross-sectional study assessing male individuals using anthropometric markers, electrical bioimpedance and vector analysis. RESULTS the healthy individuals presented larger triceps skinfold and arm circumference (p<0.001). The bioimpedance variables also presented significant higher values in this group. Significant difference was found in the confidence interval of the vector analysis performed for both the patients and healthy individuals (p<0.0001). The tolerance intervals showed that 55.20% of the patients were dehydrated, 10.30% presented visible edema, and 34.50% were within normal levels of hydration. Bioimpedance and vector analysis revealed that 52% of the patients presented decreased cell mass while 14.00% presented increased cell mass. CONCLUSIONS the differences in the body composition of patients and healthy individuals were revealed through bioimpedance and vector analysis but not through their measures of arm circumference and arm muscle area.OBJETIVO: comparar a composicao corporal de pacientes em hemodialise com sujeitos saudaveis, por diferentes metodos de avaliacao. METODOS: estudo transversal realizado com sujeitos do sexo masculino com avaliacoes antropometricas, bioimpedância eletrica e analise vetorial. RESULTADOS: a prega cutânea tricipital e a circunferencia de braco foram maiores (p<0,001) nos sujeitos saudaveis. As variaveis da bioimpedância, tambem, tiveram valores maiores e significativos nesse grupo. O intervalo de confianca da analise vetorial dos pacientes e sujeitos saudaveis mostrou diferenca significativa (p<0,0001). Os intervalos de tolerância para hidratacao revelaram que 55,20% dos pacientes estavam desidratados; 10,30% com edema aparente e 34,50% com hidratacao normal. A bioimpedância e a analise vetorial determinaram que 52% dos pacientes tinham reducao e 14% aumento da massa celular. CONCLUSOES: as diferencas na composicao corporal entre pacientes e sujeitos saudaveis foram demonstradas por meio da bioimpedância e analise vetorial, mas, nao pelas medidas da circunferencia e da area muscular de braco.

Effects of four days hiking on postural control.

Hiking is a demanding form of exercise that may cause delayed responses of the postural muscles and a loss of somatosensory information, particularly when repeatedly performed for several days. These effects may negatively influence the postural control of hikers. Therefore, the aim of this study was to investigate the effects of a four-day hike on postural control. Twenty-six adults of both sexes travelled 262 kilometers, stopping for lunch and resting in the early evening each day. Force platforms were used to collect center of pressure (COP) data at 100 Hz for 70 seconds before hiking started and immediately after arriving at the rest station each day. The COP time course data were analyzed according to global stabilometric descriptors, spectral analysis and structural descriptors using sway density curve (SDC) and stabilometric diffusion analysis (SDA). Significant increases were found for global variables in both the anterior-posterior and medial-lateral directions (COP sway area, COP total sway path, COP mean velocity, COP root mean square value and COP range). In the spectral analysis, only the 80% power frequency (F80) in the anterior-posterior direction showed a significant increase, reflecting the increase of the sway frequencies. The SDC revealed a significant increase in the mean distance between peaks (MD) and a significant decrease in the mean peak amplitudes (MP), suggesting that a larger torque amplitude is required for stabilization and that the postural stability is reduced. The SDA revealed a decrease in the long-term slope (Hl) and increases in the short-term (Ks) and the long-term (Kl) intercepts. We considered the likelihood that the presence of local and general fatigue, pain and related neuromuscular adaptations and somatosensory deficits may have contributed to these postural responses. Together, these results demonstrated that four days of hiking increased sway frequencies and deteriorated postural control in the standing position.

Analysis of postural control in elderly on horizontal and inclined surfaces using classical descriptors and DFA

Understanding how the postural control system is impaired with aging can help identify elderly at risk of falling. In order to study the postural control, center of pressure (COP) behavior can be analyzed. The objective of this study was to evaluate the capacity of Detrended Fluctuation Analysis (DFA) to discriminate the postural control of elderly in horizontal and inclined (14 degrees) surfaces, with and without visual input, comparing the results with the ones obtained with the classical variables, like mean velocity and total COP displacement. Results with classical variables revealed significant differences in all comparisons realized, but DFA was not able to classify the differences between conditions. It is suggested further studies to verify the efficiency of DFA in physiologically different groups, like subjects with some pathology that affects the balance or the ones wearing a robotic prosthesis from healthy subjects, in which it seems to have a greater sensitivity.

Composição corporal de pacientes renais crônicos em hemodiálise: antropometria e análise vetorial por bioimpedância

OBJECTIVE to compare the body composition of patients undergoing hemodialysis with that of healthy individuals using different methods. METHOD cross-sectional study assessing male individuals using anthropometric markers, electrical bioimpedance and vector analysis. RESULTS the healthy individuals presented larger triceps skinfold and arm circumference (p<0.001). The bioimpedance variables also presented significant higher values in this group. Significant difference was found in the confidence interval of the vector analysis performed for both the patients and healthy individuals (p<0.0001). The tolerance intervals showed that 55.20% of the patients were dehydrated, 10.30% presented visible edema, and 34.50% were within normal levels of hydration. Bioimpedance and vector analysis revealed that 52% of the patients presented decreased cell mass while 14.00% presented increased cell mass. CONCLUSIONS the differences in the body composition of patients and healthy individuals were revealed through bioimpedance and vector analysis but not through their measures of arm circumference and arm muscle area.OBJETIVO: comparar a composicao corporal de pacientes em hemodialise com sujeitos saudaveis, por diferentes metodos de avaliacao. METODOS: estudo transversal realizado com sujeitos do sexo masculino com avaliacoes antropometricas, bioimpedância eletrica e analise vetorial. RESULTADOS: a prega cutânea tricipital e a circunferencia de braco foram maiores (p<0,001) nos sujeitos saudaveis. As variaveis da bioimpedância, tambem, tiveram valores maiores e significativos nesse grupo. O intervalo de confianca da analise vetorial dos pacientes e sujeitos saudaveis mostrou diferenca significativa (p<0,0001). Os intervalos de tolerância para hidratacao revelaram que 55,20% dos pacientes estavam desidratados; 10,30% com edema aparente e 34,50% com hidratacao normal. A bioimpedância e a analise vetorial determinaram que 52% dos pacientes tinham reducao e 14% aumento da massa celular. CONCLUSOES: as diferencas na composicao corporal entre pacientes e sujeitos saudaveis foram demonstradas por meio da bioimpedância e analise vetorial, mas, nao pelas medidas da circunferencia e da area muscular de braco.

Avaliação da inicialização da marcha na gestante de baixo risco nos três trimestres gestacionais

OBJETIVOS: Descrever o processo de inicializacao da marcha de gestantes e comparar o comportamento do centro de pressao nos tres trimestres gestacionais. METODOS: Foram avaliadas 57 gestantes de baixo risco, com idades de 18 a 35 anos, em tres trimestres gestacionais, selecionadas por conveniencia. Foram dividas em tres grupos por idade gestacional - 1o trimestre (4-12 semanas), 2o trimestre (13-28 semanas) e 3o trimestre (29-42 semanas) -, sendo 19 gestantes para cada trimestre. Cada gestante foi posicionada em posicao ortostatica, com um pe em cada plataforma de forca AMTI, ficando assim ate ouvir um sinal sonoro para iniciar a marcha em um percurso de quatro metros. Os dados obtidos foram submetidos a analise estatistica com o programa SPSS. Para a comparacao dos grupos utilizou-se os teste de Kolmogorov Smirnov, teste de Tukey e o coeficiente de correlacao de Spearman. Em todas as analises considerou-se o nivel de significância de 5%. RESULTADOS: Foram encontradas diferencas significativas quando comparados os grupos 1o trimestre (GPT) e 3o trimestre (GTT), para as variaveis amplitude de oscilacao medio lateral GPT (0,4 cm) e GTT (0,2 cm) e velocidade de deslocamento medio-lateral - GPT (0,9 cm/s) e GTT (0,4 cm/s). Observou-se uma diminuicao gradativa nas variaveis de amplitude de oscilacao anteroposterior e medio-lateral, bem como, na velocidade de deslocamento do primeiro trimestre na plataforma 1 em relacao a plataforma 2. Houve diferencas significativas nas variaveis de amplitude de oscilacao medio-lateral e velocidade de deslocamento medio-lateral comparando GPT e GTT. CONCLUSAO: As variaveis analisadas apresentaram pequenas diferencas e nao constituem risco eminente para a estabilidade dinâmica da gestante.