The mechanics of a fascicle insertion into the skin by a mosquito of the type aedes aegypti has been studied experimentally using high-speed video (HSV) imaging, and analytically using a mathematical model. The fascicle is a polymeric microneedle composed of a ductile material, chitin. It has been proposed that the mosquito applies a non-conservative follower force component in addition to the ...

Skeletal muscle is widely perceived as nearly incompressible despite the fact that blood and lymphatic vessels within the endomysial and perimysial spaces undergo significant changes in diameter and length during stretch and contraction. These fluid shifts between fascicle and interstitial compartments have proved extremely difficult to measure. In this paper, we propose a theoretical framework...

The purpose of this study was to investigate the relationship between muscle fascicle length and sprint running performance in 37 male 100-m sprinters. The sample was divided into two performance groups by the personal-best 100-m time: 10.00-10.90 s (S10; n = 22) and 11.00-11.70 s (S11; n = 15). Muscle thickness and fascicle pennation angle of the vastus lateralis and gastrocnemius medialis and...

Ultrasound images were obtained of the medial gastrocnemius at different ankle joint positions with the knee extended. Fascicle length and deep fascicle angle were measured in five normally developing adults (mean age 33 years, age range 24 to 36 years) and in five normally developing children (mean age 7.8 years, age range 7 to 11 years), and in seven children with spastic diplegia (mean age 1...

The insufficient temporal resolution of imaging devices has made the analysis of very fast movements, such as those required to measure active muscle-tendon unit stiffness, difficult. Thus the relative contributions of tendon, aponeurosis, and fascicle to muscle-tendon unit compliance remain to be determined. The present study analyzed the dynamic interactions of fascicle, tendon, and aponeuros...

25 26 During human walking, muscle activation strategies are approximately constant across 27 consecutive steps over a short time, but it is unknown whether they are maintained over 28 a longer duration. Prolonged walking may increase tendinous tissue compliance, which 29 can influence neural activation, but the neural responses of individual muscles have not 30 been investigated. This study in...

On the basis of differences in physiology, e.g., histochemical properties and spindle density, and the structural design of the cat soleus (SO) and medial gastrocnemius (MG) muscles, we hypothesized that 1) fascicle length changes during overground walking would be both muscle and slope dependent, which would have implications for the muscles' force output as well as sensory function, and that ...

This study assessed muscle-specific force in vivo following strength training in old age. Subjects were assigned to training (n = 9, age 74.3 +/- 3.5 yr; mean +/- SD) and control (n = 9, age 67.1 +/- 2 yr) groups. Leg-extension and leg-press exercises (2 sets of 10 repetitions at 80% of the 5 repetition maximum) were performed three times/wk for 14 wk. Vastus lateralis (VL) muscle fascicle forc...

We have developed a technique to determine fascicle length in human vastus lateralis muscle in vivo by using ultrasonography. When the subjects had the knee fully extended passively from a position of 110 degree flexion (relaxed condition), the fascicle length decreased from 133 to 97 mm on average. During static contractions at 10% of maximal voluntary contraction strength (tensed condition), ...

The purpose of this study was to choose between two popular models of skeletal muscle: one with the parallel elastic component in parallel with both the contractile element and the series elastic component (model A), and the other in which it is in parallel with only the contractile element (model B). Passive and total forces were obtained at a variety of muscle lengths for the medial gastrocne...