Spinal posture in the sagittal plane is associated with future dependence in activities of daily living: a community-based cohort study of older adults in Japan.
BACKGROUND
Accumulated evidence shows how important spinal posture is for aged populations in maintaining independence in everyday life. However, the cross-sectional designs of most previous studies prevent elucidation of the relationship between spinal posture and future dependence in activities of daily living (ADL). We tried to clarify the association by measuring spinal posture noninvasively in a community-based prospective cohort study of older adults, paying particular attention to thoracic curvature, lumbar curvature, sacral hip angle, and inclination to determine which parameter is most strongly associated with dependence in ADL.


METHODS
Spinal posture was evaluated in 804 participants (338 men, 466 women, age range: 65-94 years) who were independent in ADL at baseline. We defined dependence in ADL as admission to a nursing home or need of home assistance. During the 4.5-year follow-up period, 126 (15.7%) participants became dependent in ADL. The relationship between the spinal posture parameters and outcome was assessed by dividing the participants into sex-specific quartiles of the parameters.


RESULTS
Only inclination (angle subtended between the vertical and a line joining C7 to the sacrum) was associated with outcome, although lumbar curvature also showed a marginal association. The age- and sex-adjusted odds ratio for a 1 unit increase in the quartiles of inclination was 1.79 (confidence interval: 1.44, 2.23). After mutual adjustment for the 4 parameters, statistical significance for inclination still remained, with no substantial changes in the association estimates.


CONCLUSIONS
This study indicates that spinal inclination is associated with future dependence in ADL among older adults.
Department of Environmental and Occupational Health, School of Medicine, Toho University, 5-21-16 Omori-nishi, Otaku, Tokyo 143-8540, Japan.
Kojiro
K
Kamitani
Takehiro
T
Michikawa
Satoko
S
Iwasawa
Norihito
N
Eto
Taichiro
T
Tanaka
Toru
T
Takebayashi
Yuji
Y
Nishiwaki
D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D015577:Geriatric Assessment / Q000379:methods; D006801:Humans; D057187:Independent Living / Q000706:statistics & numerical data*; D007564:Japan / Q000453:epidemiology; D008124:Locomotion; D008161:Lumbosacral Region / Q000473:pathology; D008297:Male; D053580:Muscle Strength; D009140:Musculoskeletal Diseases / Q000453:epidemiology / Q000503:physiopathology; D004856:Postural Balance; D011187:Posture; D011446:Prospective Studies; D013131:Spine / Q000503:physiopathology