OBJECTIVES The purpose of the study was to establish regression equations that could be used to predict muscle thickness and pennation angle at different intensities from electromyography (EMG) based measures of muscle activation during isometric contractions. DESIGN Cross-sectional study. METHODS Simultaneous ultrasonography and EMG were used to measure pennation angle, muscle thickness an...

Fascicle curvature of human medial gastrocnemius muscle (MG) was determined in vivo by ultrasonography during isometric contractions at three (distal, central, and proximal) locations (n = 7) and at three ankle angles (n = 7). The curvature significantly (P < 0.05) increased from rest to maximum voluntary contraction (MVC) (0.4-5.2 m(-1)). In addition, the curvature at MVC became larger in the ...

[Purpose] This study aimed to quantitatively analyze characteristics of and changes in internal muscle structure according to the time of delayed onset muscle soreness (DOMS) using ultrasound imaging, thereby presenting clinical evidential data for evaluation of muscle damage. [Subjects] We recruited 38 male subjects. [Methods] Ultrasound images of the medial gastrocnemius muscle prior to induc...

INTRODUCTION Muscle performance depends on the geometrical arrangement of fascicles and contribution of connective tissue both external and internal to the muscle belly. During concentric contractions the muscle belly shortens, the pennation angle increases and the belly thickness changes as a muscle produces force and power. As we age, the muscle structural parameters change [1] and this may c...

Diffusion-tensor magnetic resonance imaging (DT-MRI) offers objective measures of muscle characteristics, providing insights into age-related changes. We used DT-MRI to probe skeletal microstructure and architecture in a large healthy-aging cohort, with the aim characterizing differences comparing these strength. recruited 94 participants (43 female; median age = 56, range 22-89 years) measured...

INTRODUCTION Muscle weakness determines functional impairment in spastic cerebral palsy (SCP). Measurement of specific force (SF) allows for strength comparison with unimpaired populations (controls) accounting for neural (activation and coactivation), architectural (fascicle length and pennation angle), and structural differences (moment arm length). METHODS Medial gastrocnemius (MG) SF (and...

The aim of this study was to investigate the changes of musculotendon parameters of triceps brachii in persons after stroke based on subject-specific biomechanical modeling technique combined with in vivo ultrasound measurement. Five chronic stroke survivors and five normal control subjects were recruited. B-mode ultrasound was applied to measure muscle pennation angle and the optimal length of...

Abstract Pennate muscle is characterized by fibers that are oriented at a certain angle (pennation angle) relative to the muscle’s line of action and rotation during contraction. This fiber amplifies shortening velocity muscle, match loading conditions without any control system. unique variable gearing mechanism, which Architecture Gear Ratio (AGR), involves complex interaction among three key...