Natural aging course of lumbar extensor muscle mass and strength in community-dwelling older women: a 1-year prospective observational study

Lumbar Extensor Muscle Strength and Physical Performance in Community-Dwelling Older Adults: Findings From SarcoSpine Cohort

BACKGROUND

The lumbar extensor muscles (LEMs) play an important role in body posture and physical function in older adults. Because lumbar extensor strength decreases more rapidly than limb muscle strength with age, it should be evaluated to aid healthy aging. This study investigated the association between LEM strength and physical performance in community-dwelling older adults.

METHODS

This prospective observational cohort study of spinal sarcopenia (SarcoSpine) was conducted at a single center. One hundred and ten consecutive individuals who completed the baseline survey, including conventional sarcopenic indices, lumbar spine three-dimensional magnetic resonance imaging, isokinetic lumbar extensor strength, and physical performance tests (Short Physical Performance Battery, Berg Balance Scale, and Back Performance Scale [BPS]), were enrolled. A multivariate linear regression analysis was performed to determine the variables for evaluating their association with LEM strength.

RESULTS

Among the conventional sarcopenic indices, gait speed was significantly correlated with Short Physical Performance Battery results and Berg Balance Scale score in men and women. Handgrip strength was significantly correlated with the BPS score for both sexes. In the multivariable linear regression, age (β = -2.12, p < .01) and BPS score (β = -3.54, p = .01, R2 = .29) were independent indicators of LEM strength.

CONCLUSIONS

Our findings reveal the substantial association between LEM strength and BPS score in older women. The targeted intervention aimed at improving the LEMs strength would be needed to enhance physical performance in the aging population.

Quantitative multi-parameter assessment of age- and gender-related variation of back extensor muscles in healthy adults using Dixon MR imaging

OBJECTIVES

Investigate sex differences in age-related back extensor muscle degeneration using Dixon MRI and analyze the relationship between quantitative muscle parameters and back muscle strength in healthy adults.

METHODS

105 healthy subjects underwent lumbar Dixon MRI. Fat fraction (FF), cross-sectional area (CSA), functional CSA (FCSA), and relative FCSA (RFCSA) of multifidus muscle (MF) and erector spinae (ES) were quantified. Back extension muscle strength was measured using an external fixation dynamometer. ANOVA with post hoc Tukey correction was used for age group comparisons. Partial and Spearman's correlation analyzed relationships between age, muscle parameters, and muscle strength.

RESULTS

MF and ES FF significantly increased with age in both genders (r = 0.55-0.85; p < 0.001). Muscle FF increased prominently for females (40-49 years, MF and 50-59 years, ES) and males (60-73 years, MF and ES). In females, total ES FCSA and RFCSA (r =  - 0.42, - 0.37; p < 0.01) correlated with age. While in males, all MF and ES muscle size parameters, except total MF CSA, correlated with age (r =  - 0.30 to - 0.58; p < 0.05). Back extension muscle strength correlated with mean FF, total CSA, and total FCAS for MF and ES individually (p < 0.001). The combined MF + ES FCSA correlation coefficient (r = 0.63) was higher than FF (r =  - 0.51) and CSA (r = 0.59) (p < 0.001).

CONCLUSIONS

Age-related back extensor muscle degeneration varies by muscle type and sex. FCSA has the highest association with back muscle strength compared to FF and CSA.

CLINICAL RELEVANCE STATEMENT

The investigation of sex differences in age-related back extensor muscle degeneration utilizing Dixon imaging may hold significant implications for evaluating spine health and enabling earlier intervention. Muscles' FCSA could contribute to acquiring additional evidence for reflecting muscle function change.

KEY POINTS

• The multifidus muscle (MF) and erector spinae (ES) fat fraction (FF) increased with age at all lumbar disc levels in females and males. • Age-related changes in muscle morphological quantitative parameters of healthy adults were specific by muscle type and gender. • The muscle functional cross-sectional area (FCSA) measured by Dixon imaging may better monitor back extensor muscle strength changes than muscle FF and cross-sectional area (CSA).

The effects of back extensor strength in different body positions on health-related quality of life in patients with degenerative spinal deformity

BACKGROUND

Degenerative spinal deformity (DSD) is believed to originate from degeneration of the discs and facet joints and vertebral wedging. Currently, the nosogeny of DSD is not yet fully clarified and there has been no systematic study on the impact of their lower back muscle strength on quality of life.

OBJECTIVE

To determine the characteristics of back extensor strength (BES) in different body positions and examine their correlations with health-related quality of life (HQOL) in degenerative spinal deformity (DSD) patients.

METHODS

Participants comprised 60 DSD patients and 40 healthy volunteers. Maximal isometric BES was evaluated by dynamometers with the subject in three different positions (standing, prone, sitting). The visual analogue scale (VAS) score, Oswestry Disability Index (ODI), Roland-Morris Disability Questionnaire (RMQ), and 36-item Short Form Health Survey (SF-36) score were used to evaluate patient HQOL. Correlations between the BES in different body positions and HQOL were analysed.

RESULTS

The BES values in three body positions were significantly smaller in DSD patients than healthy subjects (P< 0.05). The standing BES was found to be negatively associated with ODI and RMQ (R= 0.313, p< 0.05 and R= 0.422, p< 0.01, respectively). A negative relationship between sitting BES and RMQ was also seen (R= 0.271, p< 0.05). In addition, the standing and prone BES were positively correlated with the physical functioning score of the SF-36 (R= 0.471, p< 0.01 and R= 0.289, p< 0.05, respectively), and the sitting BES was positively correlated with the role-physical score of the SF-36 (R= 0.436, p< 0.01).

CONCLUSION

The results indicate that the back extensor muscle is compromised in DSD patients and there are differences in predicting the severity of disability and physical HQOL scores with BES in different positions. Standing BES was the most reliable contributor to HQOL among three body positions.