RESUMO
OBJECTIVE: The objective of this study was to determine the accuracy of 3 clinical tests (lateral step [LS], tandem gait [TG], and single-leg stance [SS]) in identifying older women with reduced hip abductor muscle strength and to determine the post-test probability of each test and of their combination in changing the certainty of diagnosis. METHODS: In this cross-sectional study, a total of 123 older women received clinical testing to obtain the variables LS height, time for TG execution, percentage of errors in TG, and time of permanence on SS and were tested for isometric hip abductor peak torque using an isokinetic dynamometer. Only the dominant lower limb was evaluated. Multiple linear regression analysis with adjustment was performed to determine the association among variables, followed by the receiver operating characteristic curve to identify clinical variables that can discriminate older women with reduced abductor muscle strength. Post-test probability was then calculated based on the receiver operating characteristic curve data. RESULTS: Although the 4 clinical variables showed correlation with abductor peak torque, only LS and TG time were able to discriminate reduced abductor muscle strength with low accuracy (area under the curve was between 0.5 and 0.7). However, the combination of LS and TG time increased post-test probability from 47% (prevalence of weakness in the population) to 76% when both tests were positive and reduced it from 47% to 18% when both tests were negative. CONCLUSION: The combination of the LS test and TG time is useful for the indirect assessment of hip abductor strength in community-dwelling older women. IMPACT: Hip abductor muscle strength is extremely important for function in older women. This study presents clinicians with simple, fast, and inexpensive methods for assessing hip abductor muscle strength.
Assuntos
Teste de Esforço , Análise da Marcha , Quadril/fisiologia , Vida Independente , Força Muscular/fisiologia , Músculo Esquelético/fisiopatologia , Idoso , Estudos Transversais , Feminino , Humanos , Equilíbrio Postural/fisiologiaRESUMO
BACKGROUND: The previous studies have investigated causes of and risk factors for falls and impairment of functional capability in older adults. However, the biomechanical factors involved in functional performance and postural control, and the contribution of hip muscles, are still unknown. AIMS: The aim of the present study was to verify the association between the muscle function of hip abductors and adductors and static and dynamic balance, in a narrow base of support, in community-dwelling older adults. METHODS: Eighty-one older adults, including both women and men, were evaluated. Tandem gait and single-leg stance were used to assess static and dynamic balance, and an isokinetic dynamometer was used to analyze muscle function (peak torque and rate of torque development according to body weight). Data were analyzed by a multivariate linear regression test without adjustment and with adjustment using two models: adjustment I (sex) and adjustment II (age). RESULTS: There was a statistically significant association between peak torque of abductor in single-leg stance and tandem gait speed. The PT of hip adductors contributed to static balance performance, in a narrow base of support from the unadjusted data and from the adjusted data by sex. CONCLUSION: The findings of the present study are relevant, because if deficits in balance and functionality in older adults can be linked to a decline in maximum muscle strength of hip abductors, this parameter can be treated to maintain independence in older adults for as long as possible.
Assuntos
Articulação do Quadril/fisiologia , Músculo Esquelético/fisiologia , Equilíbrio Postural/fisiologia , Torque , Acidentes por Quedas/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Feminino , Análise da Marcha , Humanos , Vida Independente , Masculino , Pessoa de Meia-Idade , Força Muscular/fisiologia , Fatores de Risco , Velocidade de Caminhada/fisiologiaRESUMO
This study assessed the contribution of the "anchor system's" haptic information to balance control during walking at two levels of difficulty. Seventeen young adults and seventeen older adults performed 20 randomized trials of tandem walking in a straight line, on level ground and on a slightly-raised balance beam, both with and without the use of the anchors. The anchor consists of two flexible cables, whose ends participants hold in each hand, to which weights (125â¯g) are attached at the opposing ends, and which rest on the ground. As the participants walk, they pull on the cables, dragging the anchors. Spatiotemporal gait variables (step speed and single- and double-support duration) were processed using retro-reflective markers on anatomical sites. An accelerometer positioned in the cervical region registered trunk acceleration. Walking on the balance beam increased single- and double-support duration and reduced step speed in older adults, which suggests that this condition was more difficult than walking on the level ground. The anchors reduced trunk acceleration in the frontal plane, but the level of difficulty of the walking task showed no effect. Thus, varying the difficulty of the task had no influence on the way in which participants used the anchor system while tandem walking. The older adults exhibited more difficulty in walking on the balance beam as compared to the younger adults; however, the effect of the anchor system was similar in both groups.