RESUMO
Abstract Objective To determine gender-based variations in trunk range of motion (RoM) and isometric strength (IS) in symptomatic and asymptomatic young adults. Methods In this prospective case-control study, 73 subjects with low back pain (LBP) and 80 asymptomatic subjects were analyzed. Dynamometer-based device trunk RoM and IS measurements in extension, flexion, and rotation were compared in both groups and gender-based subgroups. Multivariate analysis was used to determine factors influencing trunk RoM and IS. Results Symptomatic males had significantly less extension RoM and extension, flexion, and rotation isometric trunk strength (ITS) (p < 0.0001) compared with asymptomatic males, whereas no significant difference was found between asymptomatic and symptomatic females. However, the mean extension-flexion RoM and mean extension-flexion ITS ratios were significantly lower (p = 0.04) in asymptomatic females compared with symptomatic females. Female gender was significantly associated with less extension and flexion ITS in both asymptomatic and symptomatic subjects. Conclusion Males with LBP had significant global ITS weakness when compared with asymptomatic males. Despite no significant ITS difference in symptomatic versus asymptomatic females, LBP caused significant extension-flexion RoM and ITS imbalance in females. These gender-based variations in trunk RoM and IS, especially the extensor-flexor IS imbalance in females, must be considered while designing rehabilitation treatment protocols for LBP.
Resumo Objetivo Determinar as variações na amplitude de movimento (ADM) do tronco e na força isométrica do tronco (FIT) em jovens adultos sintomáticos e assintomáticos baseadas no gênero dos indivíduos. Métodos Neste estudo caso-controle prospectivo, 73 indivíduos com dor lombar (DL) e 80 indivíduos assintomáticos foram analisados. As medidas de ADM do tronco e FIT de extensão, flexão e rotação foram comparadas em ambos os grupos e em subgrupos organizados por gênero. A análise multivariada foi usada para determinar os fatores que influenciam a ADM do tronco e a FIT. Results Symptomatic males had significantly less extension RoM and extension, flexion, and rotation isometric trunk strength (ITS) (p < 0.0001) compared with asymptomatic males, whereas no significant difference was found between asymptomatic and symptomatic females. However, the mean extension-flexion RoM and mean extension-flexion ITS ratios were significantly lower (p = 0.04) in asymptomatic females compared with symptomatic females. Female gender was significantly associated with less extension and flexion ITS in both asymptomatic and symptomatic subjects. Conclusão Indivíduos do sexo masculino com DL apresentaram significativa fraqueza global relacionada à FIT quando comparados com indivíduos do sexo masculino assintomáticos. Apesar de não haver diferença significativa de FIT em indivíduos do sexo feminino sintomáticos versus assintomáticos, a DL impactou a ADM e a FIT de extensão-flexão em indivíduos do sexo feminino. Essas variações de ADM do tronco e FIT baseadas no sexo, especialmente o desequilíbrio extensor-flexor de força isométrica em indivíduos do sexo feminino, devem ser consideradas ao projetar-se protocolos de tratamento de reabilitação para lombalgia.