A influência de duas mochilas sobre a cinemática da coluna de crianças

This study aimed to analyze the effect of backpack load carriage over the spine. The studies that have investigated load carriage using backpacks have analyzed the lower limb dynamics and have not focused on the spine. In addition, the strategies applied by children may differ from adults as the relative weight differs between adolescents and adults. Methods: Ten schoolboys (13.9 ± 0.6 years-old; 1.53 ± 0.05 m; 44.9 ± 3.3 kg) volunteered to participate after their parents sign an informed consent form. Participants walked in a treadmill during approximately 15 minutes carrying a specially built backpack with a load that corresponded to 0.10 and 20% BW. A number of landmarks were placed over the subjects back and allowed reconstruction of the spinal profiles in the sagittal and frontal planes. The relation between the segments formed between acromium markers and the posterior superior iliac crest markers was used as a spinal rotation index. The maximum, minimal, mean and range of motion of the thoracic and lumbar regions and the whole spine were analyzed. The gait cycle was applied to normalize the gait cycle. Results indicated differences between the two loads (10%BW and 20%BW). A number of changes in the spinal kinematics was found. In the saggital plane the range of movement was unaltered, although there was an increased in the flexion, which was interpreted as a compensatory strategy to counteract the effect of the load. These results are in line with the idea that the use of a backpack increases anterior leaning of the trunk, but are in disagreement with the notion that pronounced changes in the range of motion occur. Carrying a backpack did not produce a clear effect over the variables selected to identify thoracic and lumbar spine regions in the sagittal plane. Conclusion: Carrying a load that corresponded to 20%BW influences spinal kinematics in all planes of movements. These changes may impose an important change in posture and stress applied over the posterior aspect of the vertebral column. The slow walking speed used in the present study may have not induced large changes in the kinematics of the vertebral column as in other studies in which walking was performed in greater speeds. Thus, it is suggested that weight of the backpack is not the only factor that determines the movements of the vertebral column.Este estudo visou analisar o efeito do carregamento de cargas por meio de mochilas sobre a coluna. Os estudos que investigaram o carregamento de cargas utilizando mochilas têm analisado a dinâmica de membros inferiores e não tem focado a coluna vertebral. Em adição, as estratégias aplicadas por crianças podem diferir visto que as cargas relativas podem diferir entre adolescentes e adultos. Métodos: dez escolares (13,9 ± 0,6 anos; 1,53 ± 0,05 m; 44,9 ± 3,3 kg) foram voluntários para participar do estudo após seus pais consentirem e assinarem um formulário livre e esclarecido. Os participantes caminharam em uma esteira. Durante aproximadamente 15 minutos carregando uma mochila especialmente feita que correspondia a 0,10 e 20% do peso corporal. Um número de marcas corporais foi colocada nas costas dos sujeitos que permitiram a reconstrução dos perfis da coluna nos planos sagital e frontal. A relação entre os segmentos formados pelas marcas entre os acrômios e as cristas ilíacas foi usada como um índice de rotação da coluna. Os valores máximos, mínimos, médios e as amplitudes de movimento das regiões torácica e lombar e a coluna toda foram analisados. O ciclo da marcha foi normalizado pelo contato sucessivo de dois contatos do calcanhar com o solo. Resultados indicaram diferenças entre as cargas (10 e 20% PC). Um número de mudanças na cinemática da coluna foi encontrada. No plano sagital a amplitude de movimento permaneceu inalterada, todavia, houve um aumento na flexão a qual foi interpretada como uma estratégia compensatória em resposta ao efeito da carga. Os resultados estão em linha com a idéia que o uso de mochilas aumenta a inclinação anterior do tronco, mas em discordância com a noção que pronunciadas mudanças na amplitude de movimento ocorrem. O carregamento de cargas não produz um efeito claro sobre as variáveis selecionadas para identificar as alterações nas regiões lombar e torácica no plano sagital. Conclusão: o carregamento de cargas que correspondem a 20% PC influenciam a cinemática da coluna em todos os planos de movimento. Essas mudanças podem impor importantes mudanças sobre a postura e o estresse aplicado sobre os aspectos anteriores e posteriores da coluna vertebral. A baixa velocidade de deslocamento usada no presente estudo podem não ter induzido grandes mudanças na cinematica da coluna vertebral, como demonstrado em outros estudos que usaram maiores velocidades de deslocamento. Desta forma, sugere-se que o peso da mochila não é o único ator que determina os movimentos da coluna vertebral

CHANGES IN POSTURAL CONTROL POST AN 8-WEEK DANCE PROGRAM IN FEMALE ELDERLY

This study investigated the effect of an 8wk dance program on orthostatic postural control in elderly. Thirty-four elderly participants were randomly assigned to dance group (DG: n=19; 69.1 ± 6.57 years, 72.5 ± 11.7kg) and control group (CG: n=15; 71.5 ± 7.45 years; 70.9 ± 9.3kg). A force plate was used to measure three dimensional ground reaction force data in three conditions: narrow stance position eyes open and closed and tandem position eyes open, randomly registered over a period of 60 seconds pre and post the intervention. The mean velocity sway and the COP path area were calculated. The results showed that the ballroom dancing program with low/moderate intensity significantly improved balance. Dance would be an optimal activity for an elderly population since it can improve postural control and thus prevent fall incidence

Kinematic Variables of Disabled Swimmers and Their Correlation With the International Paralympic Committee Classification.

This study described the kinematic variables of disabled swimmers' performance and correlated them with their functional classification. Twenty-one impaired swimmers (S5-S10) performed 50-m maximum front-crawl swimming while being recorded by four underwater cameras. Swimming velocity, stroke rate, stroke length, intracycle velocity variation, stroke dimensions, hand velocity, and coordination index were analyzed. Kendall rank was used to correlate stroke parameters and functional classification with p .05). Thus, some objective kinematic variables of the impaired swimmers help to support current classification. Improving hand velocity seems to be a crucial point to be improved among disabled swimmers

Comparação de inibições medulares entre indivíduos com doença de Parkinson e saudáveis

O objetivo do presente estudo foi comparar os níveis de inibição pré-sináptica (IPS) e inibição recíproca (IR) entre indivíduos com Doença de Parkinson e saudáveis e, a correlação entre essas inibições e a rigidez muscular e a severidade clínica de indivíduos com Doença de Parkinson (avaliadas através da Escala Unificada de Avaliação da Doença de Parkinson). Foram avaliados 11 indivíduos nos estágios 2 e 3 da doença e 13 indivíduos saudáveis pareados pela idade. A IPS foi menor em indivíduos com Doença de Parkinson (31,6%) do que em saudáveis (67,1%) (p = 0,02). A IR não diferiu entre indivíduos com Doença de Parkinson (26,9%) e saudáveis (27,6%) (p = 0,91). Adicionalmente, não foram detectadas correlações entre os níveis de IPS com a rigidez e a severidade clínica (p >; 0,05). Portanto, mecanismos inibitórios não explicam totalmente a rigidez muscular e a severidade clinica da doença. Alterações entre ativação de músculos agonistas e antagonistas parecem estar relacionadas a influências supraespinhais anormais nos mecanismos espinhais decorrentes da doença.The purposes of the present study were to compare presynaptic inhibition (PI) and disynaptic reciprocal inhibition (DRI) levels between parkinsonians and healthy individuals and to verify the correlation of such inhibitions with muscle rigidity and clinical severity (assessed by the Unified Parkinson Disease Rating Scale). We evaluated 11 parkinsonians in stages 2 and 3 of the disease and 13 healthy individuals matched for age. The PI was significant lower in parkinsonians (31.6%) than in healthy individuals (67.1%) (p = 0.02). The DRI did not differ between parkinsonians (26.9%) and healthy individuals (27.6%) (p = 0.91). Furthermore, no significant correlation was observed between PI with muscle rigidity and clinical severity (p >; 0.05). Therefore, inhibitory mechanisms do not fully explain the cause of muscle rigidity and clinical severity of parkinsonians. Changes between the activation of agonist and antagonist muscles seem to be caused by abnormal supraspinal influence on spinal mechanisms

Body mass as a factor in stature change

Abstract Background. Back pain is a common condition which has been described as a serious public health problem. Spinal shrinkage has been used as an index of spinal loading in a range of tasks. Epidemiological evidence shows that body mass index (BMI: 30 kg/m 2 ) is related to the development of low back pain however, no studies have described the stature change patterns of obese individuals. This study aimed to compare changes in stature after an exercise task in obese and non-obese individuals. Methods. Twenty volunteers were divided into two equal groups; obese: BMI > 30 kg/m 2 , non-obese: BMI < 25 kg/m 2 . Stature was measured at 3 min intervals during a 30 min walking task and a 30 min standing recovery period. Tests were performed on two occasions, once with participants loaded during the walking task (10% body mass) and once unloaded. The influence of obesity and load condition on the magnitude and rate of stature change were compared by a two-way ANOVA. Findings. In both groups the stature loss was greater in the loaded than unloaded condition (mean (SD)) (6.52 (1.45) mm and 3.55 (0.93) mm non-obese; 8.49 (1.75) mm and 7.02 (1.32) mm obese: P = 0.016). The obese presented a greater reduction in stature in both task conditions. The obese group were unable to recover stature regardless of the task condition during the recovery period (loaded: 0.06 (0.3) mm; unloaded: 0.32 (0.6) mm; P = 0.013). Interpretation. It was concluded that the acute response of the spine to loading may represent a risk factor for low back pain in the obese, in addition to the chronic adaptations previously reported. A greater period of recovery may be necessary for obese individuals to re-establish intervertebral disc height. These findings may help to explain the high incidence of back disorders in obese individuals

<b>Assessment of motor imagery ability and training</b>

The aim of this study was to evaluate changes in motor imagery ability in response to a specific dart throwing training. Twelve subjects (17-22 years) with no previous experience in dart throwing or imagery agreed to participate. Changes in imagery ability were assessed using the Sports Imagery Questionnaire before (pretreatment) and after (post-treatment) an imagery training program consisting of 10 sessions. Retention (RET) was assessed 2 weeks after training. The program included mental exercises designed to develop vivid images, to control one’s own images, and to increase perception about performance. Comparison of the imagery training conditions (training alone, training accompanied, observing a colleague, and during assessment) showed no differences between the pretreatment, post-treatment and RET evaluations. Although imagery ability did not respond to training, significant differences between imagery domains (visual, auditory, kinesthetic, and animic) were found (p<0.05), except between the visual and animic domains (p=0.58). These differences might be related to subject’s domain preference subject during the imagery process and to the nature of the task in which the skill technique used seems to be a relevant aspect