Reliability of lower extremity strength measures in persons with chronic stroke

Abstract

Objective-To determine the reliability of isokinetic concentric strength measures of both the hemiparetic and non-involved limbs for flexion and extension motions of the hip, knee, and ankle joints in individuals who have had a stroke.Design-Test-retest, repeated-measures intraobserver reliability design. Setting-Tertiary rehabilitation center.Participants-20 community-dwelling individuals who have had a stroke, with motor deficits ranging from 3 to 6 on the Chedoke-McMaster Stroke Assessment; volunteer sample. Interventions-Not applicable.Main Outcome Measures-Peak torque and average torque (ie, mean over the range of motion tested) from an ensemble-averaged (three trials) torque-angle curve during isokinetic concentric extension and flexion movements of the ankle, knee, and hip.Results-Although peak and average torque were significantly less for the hemiparetic limb compared with the non-involved limb, the intraclass correlation coefficients (ICCs) between the two test sessions were high (0.95-0.99 for peak torque, 0.88-0.98 for average torque) for both limbs for all 3 joints. However, there was a learning effect, as observed by the slightly greater values attained from the second test session.Conclusions-Peak and average isokinetic torque can be used to assess reliably lower extremity strength in persons with chronic stroke. Practice sessions may be required before the actual test to reduce the effect of learning.

Effects of isokinetic strength training on walking in persons with stroke: A double-blind controlled pilot study

“…The Kin-Com Isokinetic Dynamometer has been shown to be accurate for position, velocity, and force. 30,31 The calibration of the instrument was tested before the study with known weights and was accurate to within ±1 N. All participants had a practice session 2 to 4 days before the actual testing day to reduce the learning effect as recommended by Eng et al 17 An angular velocity of 60°/s was initiated throughout their available range of motion (as assessed by their active range on the paretic side) for the isokinetic strength assessment. This velocity was selected because the majority of our participants had difficulty generating faster movements.…”

“…The strength assessment protocol has been described previously and shown to be reliable in persons with stroke with intra-class correlation coefficients greater than 0.85 for average torque values. 17 …”

“…In addition, muscle strengthening was not recommended because it was thought to increase spasticity and rein-force abnormal movement. 15 Recent studies, however, have shown that strength testing can be done reliably in individuals with spasticity [16][17][18] and that strength training is not associated with increases in spasticity. 11,19 Several studies have suggested that lower extremity strength training can improve functional performance in addition to self-perceived health in individuals with stroke.…”

Confiabilidade das medidas de dinamometria isocinética computadorizada para os movimentos do tronco em sobreviventes de acidente vascular encefálico com hemiparesia crônica

“…Uma dessas deficiências adquiridas após o AVE, caracteriza-se pela diminuição da força muscular, conhecida como hemiparesia e é definida como a ausência da habilidade de gerar níveis normais de força muscular 25,26 .…”

“…A tabela 4 permite ainda melhor observar uma maior constância de valores de ICC para os movimentos de flexão, ao mesmo tempo em que apresenta uma maior variação e ICC ligeiramente menores para os movimentos de extensão do tronco, com tendência para melhores repetições para ambos examinadores durante o reteste, podendo sugerir um efeito relacionado ao fator aprendizagem, bem discutido em outros estudos que avaliaram confiabilidade 25,34 . Esses fatos corroboram com nosso estudo visto que os valores de ICC para as análise de P e T variaram proporcional ao aumento da velocidade angular para o grupo com hemiparesia, mas não interfere no grupo sem hemiparesia (Tabelas 5).…”