Neuromuscular Attributes Associated With Lower Extremity Mobility Among Community-Dwelling Older Adults

• Published in: The journals of gerontology. Series A, Biological sciences and medical sciences Biological sciences and medical sciences, 2019-03, Vol.74 (4), p.544-549
• Main Authors: Jacob, Mini E, Travison, Thomas G, Ward, Rachel E, Latham, Nancy K, Leveille, Suzanne G, Jette, Alan M, Bean, Jonathan F
• Format: Article
• Language: English
• Subjects: Aged; Ankle; Ankle Joint - physiology; Balance; Body mass index; Cognition; Cognitive ability; Cross-Sectional Studies; Feet; Female; Gait; Gait - physiology; Geriatric Assessment; Geriatrics; Humans; Independent Living; Knee; Knee Joint - physiology; Leg; Lower Extremity - physiology; Male; Mental depression; Mobility; Mobility Limitation; Muscle Strength - physiology; Neuromuscular diseases; Older people; Postural Balance - physiology; Range of Motion, Articular - physiology; Regression analysis; Rehabilitation; The Journal of Gerontology: Medical Sciences; Velocity
• ISSN: 1079-5006; 1758-535X
• DOI: 10.1093/gerona/gly102

Abstract Background The Short Physical Performance Battery (SPPB) is advocated as a screening tool in geriatric care for predicting future disability. We aimed to identify the leg neuromuscular attributes to be targeted in rehabilitative care among older adults with poor SPPB scores. Methods Boston Rehabilitative Impairment Study of the Elderly (Boston RISE) participants (n = 430) underwent assessment of neuromuscular attributes (leg strength, leg velocity, trunk extensor endurance, knee flexion range of motion [ROM], ankle ROM, and foot sensation). Linear regression models examined association between each neuromuscular attribute and SPPB, adjusting for age, race, gender, comorbidity, body mass index, depression, cognition, and other neuromuscular attributes. Results Participants with 1 SD unit higher leg strength, leg velocity, and trunk extensor endurance had 0.52, 0.30, and 0.52 points higher SPPB total score. Participants with ankle ROM impairment and foot sensory loss had 0.43 and 0.57 lower SPPB total score compared with those without these. Leg strength and trunk extensor endurance were associated with balance; leg velocity, trunk extensor endurance, and ankle ROM were associated with gait speed; and strength, trunk extensor endurance, knee ROM, and feet sensation were associated with chair stand score. Neuromuscular attributes, along with covariates, explained 40.4% of the variance in the total SPPB score, a substantial increase over the 22.7% variance explained by covariates alone. Conclusions Neuromuscular attributes affect mobility performance in older patients as measured by the SPPB. Specific impairments are associated with poor performance in specific component scores. Assessment of the SPPB components and rehabilitation of associated impairments may help improve the functional performance among older adults.