Relation between Spinal Sagittal Alignment and Physical Function of Community-dwelling Elderly Men

Abstract

The normal human spine is formed of physiological curvature, but this curvature shape becomes distorted during aging. Few reports have described the influence of distortion of the physiological spinal curvature on physical functions, particularly in elderly men. PURPOSE: To investigate the relation between the sagittal spinal alignment and physical functions in elderly men. METHODS: Subjects were 57 elderly male community residents (74.8 ± 5.8 yr, 1.57 ± 0.20 m, 58.7 ± 8.6 kg). The sagittal spinal alignment of all participants was measured on a thoracic kyphosis angle (TKA) and lumbar lordosis angle (LLA) using Spinal Mouse (Idiag AG, Switzerland). The TKA (deg) is presented as the total of angles between the upper and lower vertebral bodies from the 1st to 12th thoracic vertebrae. The LLA (deg) is presented as the total of angles between the upper and lower vertebral bodies from the 1st lumbar to the 1st sacral vertebra. Regarding physical functions, quadriceps femoris muscle strength (QMF) measured in a sitting position using a hand-held dynamometer (Anima Corp., Japan), one-leg standing (OLS) time with eyes open, maximum walking speed (MWS), 10-m obstacle course walk time (10OWT), and 6-min walking test (6MWT) were measured in all participants. Statistical analyses using Pearson's correlation coefficient were made of the association between the spinal curvature angles and measured values. StatView 5.0 software was used. A significance level of less than 5% was inferred as significant. RESULTS: The TKA and LLA were 37.3 ± 10.1 deg and -10.4 ± 9.6 deg, respectively. The QMF, time of OLS, MWS, 10OWT, and 6MWT distance were 28.3 ± 8.0 kg, 36.7 ± 37.0 s, 2.0 ± 0.6 m/s, 7.1 ± 3.6 s, and 491.1 ± 74.3 m, respectively. The LLA was significantly correlated with the MWS (r=-0.53, p<0.01), 10OWT (r=0.42, p<0.01), QMF (r=-0.40, p<0.01), 6MWT distance (r=-0.37, p<0.01), age (r=0.36, p<0.01), and OLS (r=-0.31, p<0.05), respectively. Results show that TKA was not correlated with any measured physical function parameter. CONCLUSIONS: Results suggest that the physical function of elderly men is correlated with LLA rather than TKA. Correlation with parameters related to the walking ability was significant.