Gender-Related Differences in Reliability of Thorax, Lumbar, and Pelvis Kinematics During Gait in Patients With Non-specific Chronic Low Back Pain

OBJECTIVE: To evaluate test-retest reliability of trunk kinematics relative to the pelvis during gait in two groups (males and females) of patients with non-specific chronic low back pain (NCLBP) using three-dimensional motion capture system. METHODS: A convenience sample of 40 NCLBP participants (20 males and 20 females) was evaluated in two sessions. Participants were asked to walk with self-selected speed and kinematics of thorax and lumbar spine were captured using a 6-infrared-cameras motion-analyzer system. Peak amplitude of displacement and its measurement errors and minimal detectable change (MDC) were then calculated. RESULTS: Intraclass correlation coefficients (ICCs) were relatively constant but small for certain variables (lower lumbar peak flexion in female: inter-session ICC=0.51 and intra-session ICC=0.68; peak extension in male: inter-session ICC=0.67 and intra-session ICC=0.66). The measurement error remained constant and standard error of measurement (SEM) difference was large between males (generally ≤4.8°) and females (generally ≤5.3°). Standard deviation (SD) was higher in females. In most segments, females exhibited higher MDCs except for lower lumbar sagittal movements. CONCLUSION: Although ICCs were sufficiently reliable and constant in both genders during gait, there was difference in SEM due to difference in SD between genders caused by different gait disturbance in chronic low back pain. Due to the increasing tendency of measurement error in other areas of men and women, attention is needed when measuring lumbar motion using the method described in this study.

Correction: Gender-Related Differences in Reliability of Thorax, Lumbar, and Pelvis Kinematics During Gait in Patients With Non-specific Chronic Low Back Pain

In this article, the affiliation of the first author should be changed.

Gender differences in intra limb coordination while walking in older people

Knowledge about gender differences in intra-limb coordination during walking provides insight into the adaptability of central nervous system for controlling gait in older adults. We assessed the variability and phase dynamic of the intra-limb coordination in older men and women during walking. Twenty two older people, 11 female and 11 male, participated in this study. They were asked to perform walk on a treadmill at their preferred speed. Deviation phase and mean absolute relative phase values -indicators of variability and phase dynamic of intra-limb coordination, respectively- were calculated using the data collected by a motion capture system. We used independent sample t-test for statistical analysis. The results showed that women had a significant higher deviation phase in pelvis-thigh intersegmental relationships on both sides. Additionally, the mean absolute relative phase of left pelvis-thigh, thigh-shank and shank-foot were significantly different between men and women. While women showed a lower mean absolute relative phase in pelvis-thigh, men had a lower mean absolute relative phase in shank-thigh inter-segmental relationships. We suggest that gender could affect the intra-limb coordination variability and phase dynamic during walking in older people. This may be a reflection of the great adaptability of neuromuscular system to modify control strategies for walking in older women/ men

Temperature changes during and after eccentric contractions and its effect on force and desmin loss in rat

The typical features of eccentric exercise-induced muscle damage is prolonged loss of muscle strength and the most rapid structural change in the fibers is loss of immunostaining for the intermediate filament protein, desmin. In this study isolated perfused rat muscle was used to examine the direct effect of temperature changes on the eccentric contraction-induced force and desmin loss. The left medial gastrocnemius muscle was separated and the entire lower limb was transferred into a prewarmed [35 Degree C] organ bath. Temperature was adjusted to 31 or 39 Degree C during and after eccentric contractions. Maximal isometric force and desmin loss were measured after 15 isometric or eccentric contractions. According to our data, organ bath temperature changes during or after eccentric contractions had no significant effect on force loss. However, a strong correlation between desmin loss and temperature changes during [r = 0.886, P< 0.05] and a weak correlation between desmin loss and temperature changes after [r= 0.699, P<0.05] eccentric contractions was observed. Our results suggest that cooling during eccentric contractions may decrease desmin loss but temperature changes after eccentric contractions have no effect on desmin loss