ObjectiveTo investigate the effects of asymptomatic back muscle weakness and spinal deformity on low back pain (LBP).MethodsSixty healthy subjects without LBP participated in this study. Radiography and an isokinetic/isometric dynamometer were used to respectively measure spinal scoliosis/lordosis and the strength of the trunk flexors/extensors. After 2 years, 48 subjects visited the hospital again and LBP episodes, its severity and the Korean version of the Oswestry Disability Index were assessed. Differences between the group with LBP and the group without LBP were evaluated and the association with LBP incidence and severity was determined.ResultsSex, age, and trunk strength were significantly different in both group. Sex and age were significantly positive associated with LBP incidence. The isometric trunk flexor and extensor strength, maximum isokinetic trunk flexor and extensor strength were significantly and negatively associated with the LBP severity. The maximum isokinetic trunk extensor and maximum isometric trunk extensor strength was significantly negative associated with the LBP incidence.ConclusionLBP incidence is associated with isometric and isokinetic trunk extensor weakness, whereas LBP severity is associated with age, sex, isokinetic trunk extensor and flexor weakness, isometric trunk extensor and flexor weakness.

No abstract

1)The purpose of this study was to investigate the effects of active and passive postural perturbation on ankle dorsiflexor responses in stroke patients. The subjects consisted of 13 stroke patients. Using wireless electromyography, the patients' ankle dorsiflexor muscle responses were measured under the following conditions: active dorsiflexion (AD), active perturbation (AP), and passive perturbation (PP). Tibialis anterior muscle activity increased most significantly during PP of the affected side (118.64±56.28). The most significant increase for the non-affected side was in AD (72.64±24.56). Tibialis anterior muscle activity was compared under each condition. The affected side showed significant differences between PP and AD and between PP and AP (p<.05). The non-affected side showed not significant differences between each condition. The ratios of tibialis anterior muscle activity under AP to that under AD were 1.00 on the affected side and .75 on the non-affected side and the difference was not significant (p>.05). The ratios of tibialis anterior muscle activity under PP to that under AD were 3.30 on the affected side and 1.14 on the non-affected side and the difference was significant (p<.05). Passive perturbation improved tibialis anterior muscle activity on the affected side, and training based on this approach may have the potential to improve the ankle dorsiflexion of people with stroke.

No abstract