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Human Soleus Muscle (human + soleus_muscle)

Distribution by Scientific Domains

Life Sciences	100%

Selected Abstracts

Mechanical and neural stretch responses of the human soleus muscle at different walking speeds

THE JOURNAL OF PHYSIOLOGY, Issue 13 2009
Neil J. Cronin
During human walking, a sudden trip may elicit a Ia afferent fibre mediated short latency stretch reflex. The aim of this study was to investigate soleus (SOL) muscle mechanical behaviour in response to dorsiflexion perturbations, and to relate this behaviour to short latency stretch reflex responses. Twelve healthy subjects walked on a treadmill with the left leg attached to an actuator capable of rapidly dorsiflexing the ankle joint. Ultrasound was used to measure fascicle lengths in SOL during walking, and surface electromyography (EMG) was used to record muscle activation. Dorsiflexion perturbations of 6 deg were applied during mid-stance at walking speeds of 3, 4 and 5 km h,1. At each walking speed, perturbations were delivered at three different velocities (slow: ,170 deg s,1, mid: ,230 deg s,1, fast: ,280 deg s,1). At 5 km h,1, fascicle stretch amplitude was 34,40% smaller and fascicle stretch velocity 22,28% slower than at 3 km h,1 in response to a constant amplitude perturbation, whilst stretch reflex amplitudes were unchanged. Changes in fascicle stretch parameters can be attributed to an increase in muscle stiffness at faster walking speeds. As stretch velocity is a potent stimulus to muscle spindles, a decrease in the velocity of fascicle stretch at faster walking speeds would be expected to decrease spindle afferent feedback and thus stretch reflex amplitudes, which did not occur. It is therefore postulated that other mechanisms, such as altered fusimotor drive, reduced pre-synaptic inhibition and/or increased descending excitatory input, acted to maintain motoneurone output as walking speed increased, preventing a decrease in short latency reflex amplitudes. [source]

Intramuscular innervation of the human soleus muscle: A 3D model

CLINICAL ANATOMY, Issue 5 2003
Eldon Y. Loh
Abstract The purpose of this study was to document the neural distribution patterns within the human soleus muscle using 3D computer modelling. Through serial dissection, pinning, and digitization, nerve distribution and muscle volume of a human cadaveric soleus muscle were documented and a detailed 3D computer model of neural distribution within the muscle volume was generated. Branching patterns demonstrated divisions that parallel architectural partitions within the soleus; that is, into anterior, posterior, and marginal soleus. Additionally, branching patterns demonstrated further partitioning of the posterior soleus into five distinct regions and the anterior soleus into two regions. Communication between nerve branches of the five regions of posterior soleus and between the anterior and posterior soleus were recorded. Knowledge of these anatomical partitions and their interaction is important as it will aid in the development of functional muscle models and in the understanding of normal and pathological muscle function. Clin. Anat. 16:378,382, 2003. © 2003 Wiley-Liss, Inc. [source]

Documentation and three-dimensional modelling of human soleus muscle architecture

CLINICAL ANATOMY, Issue 4 2003
Anne M. Agur
Abstract The purpose of this study was to visualize and document the architecture of the human soleus muscle throughout its entire volume. The architecture was visualized by creating a three-dimensional (3D) manipulatable computer model of an entire cadaveric soleus, in situ, using B-spline solid to display muscle fiber bundles that had been serially dissected, pinned, and digitized. A database of fiber bundle length and angle of pennation throughout the marginal, posterior, and anterior soleus was compiled. The computer model allowed documentation of the architectural parameters in 3D space, with the angle of pennation being measured relative to the tangent plane of the point of attachment of a fiber bundle. Before this study, the only architectural parameters that have been recorded have been 2D. Three-dimensional reconstruction is an exciting innovation because it makes feasible the creation of an architectural database and allows visualization of each fiber bundle in situ from any perspective. It was concluded that the architecture is non-uniform throughout the volume of soleus. Detailed architectural studies may lead to the development of muscle models that can more accurately predict interaction between muscle parts, force generation, and the effect of pathologic states on muscle function. Clin. Anat. 16:285,293, 2003. © 2003 Wiley-Liss, Inc. [source]