The 3D muscle morphology and intramuscular innervation of the digital bellies of flexor digitorum profundus: Clinical implications for botulinum toxin injection sites.

Spasticity of flexor digitorum profundus is frequently managed with botulinum toxin injections. Knowledge of the 3D morphology and intramuscular innervation of the digital bellies of flexor digitorum profundus is necessary to optimize the injections. The purpose of this study was to digitize and model in 3D the contractile and connective tissue elements of flexor digitorum profundus to determine muscle morphology, model and map the intramuscular innervation and propose sites for botulinum toxin injection.

The Effects of Power Training Frequency on Muscle Power and Functional Performance in Older Women: A Randomized Controlled Trial.

Katsoulis, K and Amara, CE. The effects of power training frequency on muscle power and functional performance in older women: a randomized controlled trial. J Strength Cond Res 37(11): 2289-2297, 2023-Low-intensity power training (PT) has emerged as an effective method for improving muscle power and functional performance in older adults.

Reliability of Lower Extremity Muscle Power and Functional Performance in Healthy, Older Women.

Evaluation of the long-term reliability of muscle power and functional performance tests in older, healthy adults is warranted since determining whether performance is consistent over longer durations is more relevant for intervention studies. . To assess the long-term test-retest reliability of measures of muscle power and lower body functional performance in healthy, nonexercising, older women.

The Effects of High- Versus Low-Intensity Power Training on Muscle Power Outcomes in Healthy, Older Adults: A Systematic Review.

Power training (PT) improves muscle power in older adults; however, intensity recommendations are less clear. A narrative approach was used to compare high- versus low-intensity PT on muscle power (and function) in healthy, older adults. Searches were performed using Medline, Embase, CINAHL, SPORTDiscus, AgeLine, and Scopus.

Mild eccentric exercise increases Hsp72 content in skeletal muscles from adult and late middle-aged rats.

The loss of muscle mass with age or sarcopenia contributes to increased morbidity and mortality. Thus, preventing muscle loss with age is important for maintaining health. Hsp72, the inducible member of the Hsp70 family, is known to provide protection to skeletal muscle and can be increased by exercise.

Higher mitochondrial respiration and uncoupling with reduced electron transport chain content in vivo in muscle of sedentary versus active subjects.

Objective: This study investigated the disparity between muscle metabolic rate and mitochondrial metabolism in human muscle of sedentary vs. active individuals.

Research Design And Methods: Chronic activity level was characterized by a physical activity questionnaire and a triaxial accelerometer as well as a maximal oxygen uptake test.

Serum leptin is not correlated with body fat in severe food restriction.

Leptin is an adipose-derived hormone with established roles in energy balance that can impact the response to refeeding after malnutrition. Although the amount of circulating leptin has traditionally been associated with the amount of adipose tissue, controversy exists as to whether this relationship is constant in both humans and animals and over a wide range of body composition. Our objective was to evaluate whether the leptin - body fat ratio is constant in the range of healthy to low body mass in female Wistar rats.

Mitochondrial function in vivo: spectroscopy provides window on cellular energetics.

Mitochondria integrate the key metabolic fluxes in the cell. This role places this organelle at the center of cellular energetics and, hence, mitochondrial dysfunction underlies a growing number of human disorders and age-related degenerative diseases. Here we present novel analytical and technical methods for evaluating mitochondrial metabolism and (dys)function in human muscle in vivo.

Synthetic signal injection using inductive coupling.

Conversion of MR signals into units of metabolite concentration requires a very high level of diligence to account for the numerous parameters and transformations that affect the proportionality between the quantity of excited nuclei in the acquisition volume and the integrated area of the corresponding peak in the spectrum. We describe a method that eases this burden with respect to the transformations that occur during and following data acquisition. The conceptual approach is similar to the ERETIC method, which uses a pre-calibrated, artificial reference signal as a calibration factor to accomplish the conversion.

Wavelength shift analysis: a simple method to determine the contribution of hemoglobin and myoglobin to in vivo optical spectra.

The ability to quantify the contributions of hemoglobin (Hb) and myoglobin (Mb) to in vivo optical spectra has many applications for clinical and research use such as noninvasive measurement of local tissue O(2) uptake rates and regional blood content. Recent work has demonstrated an approach to independently measure oxygen saturations of Hb and Mb in optical spectra collected in vivo. However, the utility of this approach is limited without information on tissue concentrations of these species.

Mitochondrial dysfunction: impact on exercise performance and cellular aging.

Innovative noninvasive methods open a new window on the cell in vivo. This window reveals that the tempo of mitochondrial dysfunction with age varies among muscles and in proportion to Type II muscle fiber content. Exercise training can reverse age-related dysfunction, thereby providing an intervention to slow the pace of aging and disability in the elderly.

Mild mitochondrial uncoupling impacts cellular aging in human muscles in vivo.

Faster aging is predicted in more active tissues and animals because of greater reactive oxygen species generation. Yet age-related cell loss is greater in less active cell types, such as type II muscle fibers. Mitochondrial uncoupling has been proposed as a mechanism that reduces reactive oxygen species production and could account for this paradox between longevity and activity.

Mitochondrial function, fibre types and ageing: new insights from human muscle in vivo.

Mitochondrial changes are at the centre of a wide range of maladies, including diabetes, neurodegeneration and ageing-related dysfunctions. Here we describe innovative optical and magnetic resonance spectroscopic methods that non-invasively measure key mitochondrial fluxes, ATP synthesis and O(2) uptake, to permit the determination of mitochondrial coupling efficiency in vivo (P/O: half the ratio of ATP flux to O(2) uptake). Three new insights result.

Allometric scaling of strength in an independently living population age 55-86 years.

Most physiological functions vary allometrically with body size; however, few investigators have examined the relationship between strength and body size with allometric scaling. Thus, we hypothesized that allometric analysis would reveal that both the amount and quality of muscle are significant determinants of strength in the elderly. Allometric analyses were used to determine the influence of limb cross-sectional area (CSA), physical activity, demispan (distance between index-middle finger web and the sternal notch), leg length, and sex on grip and plantar flexor strength in men (n = 188) and women (n = 205) age 55-86 years.