Study Design: Cross-sectional study. Objective: To determine whether there are differences in trunk muscle characteristics between older adults with and without chronic low back pain (LBP), while controlling for age, sex, and body mass index. Background: Muscle support for the trunk is provided by the multifidi, erector spinae, psoas, and quadratus lumborum. Trunk muscle characteristics may be altered with aging and/or chronic LBP. To date, most trunk muscle research has been conducted among younger adults. Given age-related muscle changes, such as reduced size and increased intramuscular fat, studies are needed in older adults, including those comparing older adults with and without LBP. Methods: One hundred two older adults with (n = 53) and without (n = 49) chronic LBP were included. Cross-sectional area (CSA) measurements were taken by tracing inside the fascial borders on magnetic resonance images. Pixel intensity summaries were obtained to compute muscle-to-fat indices and relative muscle CSA, that is, CSA void of fat. Right/left averages for levels L2 through L5 were determined. Mixed-design analyses of covariance were used to test for differences between groups, based on LBP presence and sex, across levels (P≤.05). Results: Older adults with LBP had a greater average multifidus muscle-to-fat index (0.51 versus 0.49) and smaller average erector spinae relative muscle CSA (8.56 cm² versus 9.26 cm²) when compared to control participants without LBP. No interactions between LBP status and average muscle characteristics were found for the psoas or quadratus lumborum (P>.05). Conclusion: Up to 54% of older adult trunk muscle CSA may be fat. Women have smaller muscles and greater intramuscular fat (at lower spinal levels) than men. J Orthop Sports Phys Ther 2017;47(3):173–179. Epub 3 Feb 2017. doi:10.2519/jospt.2017.7002

Nges in muscles may minimize activity limitations and enhance participation post stroke. This article reviews the impact of aging and stroke on muscle morphology and composition, including fiber atrophy, reductions in muscle cross-sectional area, changes in muscle fiber distributions, and increases in intramuscular fat. Relationships between changes in muscle structure, muscle function, and physical mobility are reviewed. Clinical recommendations that preserve and enhance skeletal muscle in the aging adult and individuals post stroke are discussed. Future research directions that include systematic comparison of the differences in skeletal muscle between younger and older adults who have sustained a stroke are suggested....

Background. Although fear-avoidance beliefs (FABs) have been explored in younger adults and Spanish older adults, their relationships to measures of low back pa

Study Design: Intraexaminer and interexaminer, within- and between-day reliability study. Objectives: To compare the intraexaminer and interexaminer procedural reliability of ultrasound imaging (USI) thickness measurements of the lumbar multifidus muscle at rest and during a contralateral lower-limb lift (CLL) between older (60–85 years of age) and younger (18–40 years of age) adults. Background: Among younger adults, USI has been shown to be reliable and valid for assessing multifidus thickness. Older adults present with age-related changes that may impact assessment. To our knowledge, no USI studies have focused on establishing reliability for multifidus thickness assessments in older adults. Methods: Two examiners performed assessments of lumbar multifidus thickness at rest and during a CLL in 30 older and 31 younger adults. Intraclass correlation coefficient (ICC) with 95% confidence interval, standard error of measurement, 95% minimal detectable change for resting and during the CLL, and percent thickness change were calculated. Results: Within-day interexaminer procedural reliability for multifidus thickness measurements was similar among younger (ICC = 0.90–0.92) and older adults (ICC = 0.86–0.90), as was between-day intraexaminer and interexaminer reliability (younger adults, ICC = 0.84–0.94; older adults, ICC = 0.86–0.93). Throughout, estimates of percent thickness change were inconsistent (ICC = 0.31–0.86), and standard errors of measurement and minimal detectable changes were larger for older adults. Conclusion: Ultrasound imaging reliability for measurements of multifidus thickness at rest and during a CLL among older adults is consistent with previously published findings for younger adults. Among older adults, it may be preferable to have a single examiner conduct USI assessments. J Orthop Sports Phys Ther 2014;44(6):425–434. Epub 25 April 2014. doi:10.2519/jospt.2014.4584