Impact of spinal imbalance and back muscle strength on locomotive syndrome in community-living elderly people.

BACKGROUND

The Japanese Orthopaedic Association has proposed the term locomotive syndrome ("locomo") to designate a condition of individuals in high-risk groups with musculoskeletal disease who are highly likely to require nursing care. The specific characteristics of "locomo" must still be determined. The spinal column is a major and important component affected by "locomo," but no literature has examined the relationship between spinal factors and "locomo." The current study investigates the influence of spinal factors on "locomo" in the elderly.

METHODS

A total of 135 subjects >70 years old were enrolled in the study (Yakumo study). Those answering yes to least one of the seven categories in the self-assessment checklist for "locomo" were defined as having "locomo." We evaluated lateral lumbar radiographs, sagittal parameters, sagittal balance using the spinal inclination angle (SIA) as an index, spinal mobility as determined with SpinalMouse(®), back muscle strength (BMS), and body mass index (BMI).

RESULTS

Age, BMS, and SIA showed significant correlations with "locomo" and five of the seven self-assessment categories. Multivariate logistic regression analysis indicated that a decrease in BMS (OR 0.971, p < 0.001) and an increase in SIA (OR 1.144, p < 0.05) were significantly associated with "locomo." BMS had significant negative correlations with age (r = -0.363), SIA (r = -0.294), and lumbar kyphosis (r = -0.254), and positive correlations with sacral slope angle (r = 0.194). SIA had significant negative correlations with BMS (r = -0.294), lumbar spinal range of motion (ROM) (r = -0.186) and total spinal ROM (r = -0.180), and positive correlations with age (r = 0.403) and lumbar kyphosis (r = 0.593).

CONCLUSIONS

A decrease in BMS and an increase in SIA may be the most important risk factors for "locomo." Lumbar kyphosis is an important factor related to BMS and SIA. Back muscle strengthening and lumbar spinal ROM exercises could be useful for improving the status of an individual suffering from "locomo."