Musculoskeletal System Commons^™

Acute Effects Of Trunk Stretching On Aortic Arterial Stiffness And Central And Peripheral Blood Pressure In Middle-Aged Older Adults, Kylee West

Electronic Theses and Dissertations

BACKGROUND: Physical activity may alter the trajectory of age-related arterial stiffening, which is associated with cardiovascular morbidity and mortality. Trunk stretching has reduced arterial stiffness (AS) in young males, but its effect in middle-aged to older adults is unclear. This study examined the effects of passively assisted trunk stretching (PATS) on aortic arterial stiffness and central and peripheral blood pressure in middle-aged to older adults. METHODS: Carotid-femoral pulse wave velocity (cf-PWV) and Augmentation Index normalized to a heart rate of 75 beats per minute (AIx75) were measured in 28 middle-aged to older adults (14M/14F; 72 ± 7 years; 28.5 …

Evaluating Sex Related Differences In The Osteocyte Lacunar Canalicular Network Across The Lifespan: A Confocal Laser Scanning Microscopy Approach, Gina Tubo

Williams Honors College, Honors Research Projects

Bone is a dynamic tissue with the ability to remodel itself. This capability is facilitated via communication mechanisms through the osteocyte-lacunar-canalicular (LCN) network. Osteocytes are bone cells housed in small, hollow spaces called lacunae. Lacunae are linked by canals called canaliculi. A diminished network can lead to the inability to form bone following breakdown. A decrease in osteocyte-LCN density has been shown to correlate with aging (Ashique et al. 2017). This decline leads to the development of osteoporosis. Osteoporosis preferentially affects women. Prior studies have shown that women older than 50 are four times more likely to be osteoporotic when …

Anticipatory Postural Adjustments And Spatial Organization Of Motor Cortex: Evidence Of Adaptive Compensations In Healthy Older Adults, Jo Armour Smith, Beth E. Fisher

Physical Therapy Faculty Articles and Research

During anticipated postural perturbations induced by limb movement, the central nervous system generates anticipatory postural adjustments (APAs) in the trunk and hip musculature to minimize disturbances to equilibrium. Age-related changes in functional organization of the nervous system may contribute to changes in APAs in healthy older adults. Here we examined if altered APAs of trunk/hip musculature in older adults are accompanied by changes in the representation of these muscles in motor cortex. Twelve healthy older adults, 5 with a history of falls and 7 nonfallers, were compared with 13 young adults. APAs were assessed during a mediolateral arm raise task …

Mechanisms Of Fatigue With Aging: Evidence From The Whole-Limb To The Single Cell In Humans, Christopher W. Sundberg

Dissertations (1934 -)

Aging is accompanied by a loss of muscle mass and increased fatigability of limb muscles making it difficult for old adults to generate the force and power necessary to perform daily activities, such as ascending a flight of stairs. The mechanisms for the age-related increase in fatigability in old and very old adults (≥80 yrs) and whether there are differences between men and women are unknown. The purpose of this dissertation was to determine the mechanisms for the age-related increase in fatigability in men and women by studying fatigue at the level of the whole-limb and within the muscle cells. …

Human Body Composition And Immunity: Visceral Adipose Tissue Produces Il-15 And Muscle Strength Inversely Correlates With Nk Cell Function In Elderly Humans, Ahmad Al-Attar, Steven R. Presnell, Jody L. Clasey, Douglas E. Long, R. Grace Walton, Morgan Sexton, Marlene E. Starr, Philip A. Kern, Charlotte A. Peterson, Charles T. Lutz

Pathology and Laboratory Medicine Faculty Publications

Natural killer (NK) lymphocyte-mediated cytotoxicity and cytokine secretion control infections and cancers, but these crucial activities decline with age. NK cell development, homeostasis, and function require IL-15 and its chaperone, IL-15 receptor alpha (IL-15Rα). Macrophages and dendritic cells (DC) are major sources of these proteins. We had previously postulated that additional IL-15 and IL-15Rα is made by skeletal muscle and adipose tissue. These sources may be important in aging, when IL-15-producing immune cells decline. NK cells circulate through adipose tissue, where they may be exposed to local IL-15. The objectives of this work were to determine (1) if human muscle, …

Metformin To Augment Strength Training Effective Response In Seniors (Masters): Study Protocol For A Randomized Controlled Trial, Douglas E. Long, Bailey D. Peck, Jenny L. Martz, S. Craig Tuggle, Heather M. Bush, Gerald Mcgwin, Philip A. Kern, Marcas M. Bamman, Charlotte A. Peterson

Physical Therapy Faculty Publications

Background: Muscle mass and strength are strong determinants of a person’s quality of life and functional independence with advancing age. While resistance training is the most effective intervention to combat age-associated muscle atrophy (sarcopenia), the ability of older adults to increase muscle mass and strength in response to training is blunted and highly variable. Thus, finding novel ways to complement resistance training to improve muscle response and ultimately quality of life among older individuals is critical. The purpose of this study is to determine whether a commonly prescribed medication called metformin can be repurposed to improve the response to resistance …

Aging And Muscle Fatigability In The Upper Extremity, Andrew Kuplic

Master's Theses (2009 -)

Aging is accompanied by reductions in strength and contraction velocity, and increased fatigability of limb muscles during high-velocity dynamic contractions. These age-related changes affect functional tasks and are well described for the lower limb, with less known about the upper limb muscles. The aims of the thesis were to compare in young and old men and women: (1) maximal torque and power of the elbow flexor muscles across a range of isokinetic velocities, and (2) the neural (supraspinal) and muscular mechanisms of fatigue induced by high-velocity dynamic contractions of the elbow flexor muscles. 28 young (23.2 ± 2.6 years) men …

Micrornas, Heart Failure, And Aging: Potential Interactions With Skeletal Muscle, Kevin A. Murach, John J. Mccarthy

Center for Muscle Biology Faculty Publications

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression by targeting mRNAs for degradation or translational repression. MiRNAs can be expressed tissue specifically and are altered in response to various physiological conditions. It has recently been shown that miRNAs are released into the circulation, potentially for the purpose of communicating with distant tissues. This manuscript discusses miRNA alterations in cardiac muscle and the circulation during heart failure, a prevalent and costly public health issue. A potential mechanism for how skeletal muscle maladaptations during heart failure could be mediated by myocardium-derived miRNAs released to the circulation is presented. An overview …

Validity Of Boston Marathon Qualifying Times, Paul M. Vanderburgh

Paul M. Vanderburgh

Purpose: To assess the validity of Boston Marathon qualifying (BMQ) standards for men and women. Methods: Percent differences between BMQ and current world records (WR) by sex and age group were computed. WR was chosen as the criterion comparison because it is not confounded by intensity, body composition, lifestyle, or environmental factors. A consistent difference across age groups would indicate an appropriate slope of the age-vs-BMQ curve. Inconsistent differences were corrected by adjusting BMQ standards to achieve a uniform percentage difference from WR. Results: BMQ standards for men were consistently ~50% slower than WR (mean 51.5% ± 1.4%, range 49.6–54.4%), …

Impaired Skeletal Muscle Blood Flow Control With Advancing Age In Humans: Attenuated Atp Release And Local Vasodilation During Erythrocyte Deoxygenation, Brett S. Kirby, Anne R. Crecelius, Wyatt F. Voyles, Frank A. Dinenno

Anne R. Crecelius

Rationale: Skeletal muscle blood flow is coupled with the oxygenation state of hemoglobin in young adults, whereby the erythrocyte functions as an oxygen sensor and releases ATP during deoxygenation to evoke vasodilation. Whether this function is impaired in humans of advanced age is unknown. Objective: To test the hypothesis that older adults demonstrate impaired muscle blood flow and lower intravascular ATP during conditions of erythrocyte deoxygenation. Methods and Results: We showed impaired forearm blood flow responses during 2 conditions of erythrocyte deoxygenation (systemic hypoxia and graded handgrip exercise) with age, which was caused by reduced local vasodilation. In young adults, …

Impaired Skeletal Muscle Blood Flow Control With Advancing Age In Humans: Attenuated Atp Release And Local Vasodilation During Erythrocyte Deoxygenation, Brett S. Kirby, Anne R. Crecelius, Wyatt F. Voyles, Frank A. Dinenno

Health and Sport Science Faculty Publications

Rationale: Skeletal muscle blood flow is coupled with the oxygenation state of hemoglobin in young adults, whereby the erythrocyte functions as an oxygen sensor and releases ATP during deoxygenation to evoke vasodilation. Whether this function is impaired in humans of advanced age is unknown.

Objective: To test the hypothesis that older adults demonstrate impaired muscle blood flow and lower intravascular ATP during conditions of erythrocyte deoxygenation.

Methods and Results: We showed impaired forearm blood flow responses during 2 conditions of erythrocyte deoxygenation (systemic hypoxia and graded handgrip exercise) with age, which was caused by reduced local vasodilation. In young adults, …

The Role Of Lower Leg Muscle Activity In Blood Pressure Maintenance Of Older Adults, Michelle M. Masterson, Amy L. Morgan, Christine E. Multer, Daniel Cipriani

Physical Therapy Faculty Articles and Research

Purpose. Age-associated muscle weakness, postural instability, and orthostatic hypotension have been identified as contributing factors to falls , but the relationships among them are not clear. Therefore, the purpose of this study, a two-way factorial design, was to investigate the differences in lower extremity (LE) muscle activity, blood pressure (BP), and heart rate (HR) between young and older individuals in an upright position. Methods. Ten young males (20-24 yrs.) and 10 older males (65-82 yrs.) stood for 15 minutes while BP, HR, and LE electromyography (EMG) were recorded at one minute intervals . A two-way ANOVA was used …