BACKGROUND Plantarflexor tightness due to muscle degenerations has been frequently documented in children with spastic cerebral palsy but the contractile behavior of muscles during ambulation is largely unclear. Especially the adaptability of gastrocnemius muscle contraction on sloped surface could be relevant during therapy. METHODS Medial gastrocnemius contractions were measured during flat...

Skeletal muscles are characterized by a large diversity in anatomical architecture and function. Muscle force and contraction are generated by contractile fiber cells grouped in fascicle bundles, which transmit the mechanical action between origin and insertion attachments of the muscle. Therefore, an adequate representation of fascicle arrangements in computational models of skeletal muscles i...

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 ...

In the companion paper (Bastiani, M. J., J. A. Raper, and C. S. Goodman (1984) J. Neurosci. 4: 2311-2328), we show that as the G growth cone reaches its choice point and turns anteriorly on the A/P fascicle, its filopodia demonstrate selective affinity for the A/P fascicle as compared to the other approximately 25 longitudinal axon fascicles, and within the A/P fascicle itself, G's filopodia se...

UNLABELLED Eccentric training for Achilles tendinosis (AT) has been reported to significantly improve patient symptoms. There has been no biomechanical explanation on the mechanism for specific rehabilitation technique. The purpose of this study was to determine changes in muscle architecture that occurred as a result of Achilles tendinosis injury and a subsequent eccentric rehabilitation progr...

Evaluation of muscle structure gives us a better understanding of how muscles contribute to force generation which is significantly altered in children with cerebral palsy (CP). While most muscle structure parameters have shown to be significantly correlated to different expressions of strength development in children with CP and typically developing (TD) children, conflicting results are found...

We compared the histologic picture of myocardial fiber disarray in thin (4 mu) and thick (25 mu) sections of tissues obtained at autopsy from 18 adults and eight infants with clinically normal hearts, from 10 hearts with concentric hypertrophy (hypertensive patients), nine with myocardial infarction and four with hypertrophic cardiomyopathy (HCM). In the thick sections, so-called bizarre myocar...

This study tested the hypothesis that the ratio of changes in muscle fascicle and tendon length that occurs with joint movement scales linearly with the ratio of the slack lengths of the muscle fascicles and tendons. We compared the contribution of muscle fascicles to passive muscle-tendon lengthening in muscles with relatively short and long fascicles. Fifteen healthy adults participated in th...

Many locomotor activities require muscles to actively lengthen, dissipate energy and decelerate the body. These eccentric contractions can disrupt cytoskeletal structures within myofibrils and reduce force output. We examined how architectural features of pennate muscles can provide a protective mechanism against eccentric muscle damage by limiting fascicle lengthening. It has been previously s...

Fascicular tachycardia Fascicular tachycardia is uncommon and not usually associated with underlying structural heart disease. It originates from the region of the posterior fascicle (or occasionally the anterior fascicle) of the left bundle branch and is partly propagated by the His-Purkinje network. It therefore produces QRS complexes of relatively short duration (0.11-0.14 s). Consequently, ...