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Biomaterials in Bone and Muscle Regeneration
Published in Rajesh K. Kesharwani, Raj K. Keservani, Anil K. Sharma, Tissue Engineering, 2022
Shesan John Owonubi, Eric Gayom, Blessing A. Aderibigbe, Neerish Revaprasadu
Muscle architecture, the arrangement of muscle fibers in relation to the axis of force generation, is constrained by the length of the muscle, the length of myofibers, the pennation angle, and the physiological cross-sectional area (Lieber and Fridén, 2000). Even in pennate muscles, adjacent myofibers have parallel alignment and the surrounding ECM is highly uniform in direction. When designing bioreactors for tissue-engineered skeletal muscle, researchers are deliberate in developing alignment within their constructs (Aubin et al., 2010; Aviss et al., 2010; Vandenburgh and Karlisch, 1989). Parallel alignment of myofibers has been shown to be important for developing phenotypically normal muscle tissue under in vitro conditions (Aubin et al., 2010; Lam et al., 2009; Vandenburgh and Karlisch, 1989; Wang et al., 2015). Researchers obtain parallel alignment through micropatterning (Cimetta et al., 2009; Flaibani et al., 2009; Huang et al., 2010; Shimizu et al., 2009), aligned deposition of fibers (Aviss et al., 2010; Choi et al., 2008; Wang et al., 2015), or by selecting a scaffold that has native parallel alignment. Myofiber alignment indicative of a mature muscle phenotype has also been induced in vitro using bioreactors that deliver mechanical or electrical stimulation to cells and/or tissue constructs (Flaibani et al., 2009; Ahadian et al., 2013; Boonen et al., 2010; Donnelly et al., 2010; Grossi et al., 2007; Langelaan et al., 2011; Powell et al., 2002; Vandenburgh and Karlisch, 1989).
Tissue Structure and Function
Published in Joseph W. Freeman, Debabrata Banerjee, Building Tissues, 2018
Joseph W. Freeman, Debabrata Banerjee
Understanding muscle architecture is necessary to understand the functional properties of different skeletal muscles. There are three common skeletal muscle arrangements: parallel (longitudinally) arranged, unipennate, multipennate, and circular (Figure 4.34). Parallel muscles have fibers that extend parallel to the muscle force-generating axis (Figure 4.34). Although the fibers extend parallel to the force-generating axis, they never extend the entire muscle length. Biceps are an example. Unipennate muscles have fibers that are oriented at a single angle relative to the force-generating axis (Figure 4.34). The angle between the fiber and the force-generating axis generally varies from 0° to 30°. The vastus lateralis is an example. Multipennate muscles are composed of fibers that are oriented at several angles relative to the axis of force generation (Figure 4.34). Most muscles fall into this category; the gluteus medius is an example. Circular muscles (sphincters) have fibers that are concentrically arranged around an opening or recess (Figure 4.34). When the muscle contracts the diameter of the opening decreases. Sphincters guard entrances and exits of internal passageways including the digestive and urinary tracts. The orbicularis oris muscle of the mouth is an example.
Muscle mechanics and neural control
Published in Youlian Hong, Roger Bartlett, Routledge Handbook of Biomechanics and Human Movement Science, 2008
The sum of active and passive components describes the functional force-length relationship of a given muscle. However, due to the differences in muscle architecture, the shape and the relative contribution of both components varies largely among different muscles (Figure 6.1C). For functional interpretations of force-length behaviour in human movement it is important to note that the area underneath the sum of active and passive components describes the 'ontrol zone'in which the neuronal system can 'etermine' force output of the muscle tendon complex.
Is there a relationship between back squat depth, ankle flexibility, and Achilles tendon stiffness?
Published in Sports Biomechanics, 2022
João Gomes, Tiago Neto, João R. Vaz, Brad Jon Schoenfeld, Sandro R. Freitas
The back squat is widely employed to enhance lower limb strength in athletes from different sports (Escamilla et al., 2001; McCurdy, Langford, Doscher, Wiley, & Mallard, 2005; Senter & Hame, 2006). This exercise has been proposed to be performed at different depths based on the premise that doing so induces different functional and morphological adaptations in the muscle-tendon complex (Bloomquist et al., 2013; Schoenfeld, 2010). For instance, a deeper back squat has been reported to be advantageous in developing lower limb strength (Bloomquist et al., 2013) and jumping height (Hartmann et al., 2012). Such strength gain is thought to occur do to a greater increase in skeletal muscle hypertrophy, as well as changes in the geometry of muscle fascicles, i.e., muscle architecture (Bloomquist et al., 2013; Schoenfeld, 2010). However, since back squat depth capacity varies across individuals (Kathiresan, Jali, Afiqah, Aznie, & Osop, 2010), it is important to understand the factors underlying back squat depth capacity.
A low-volume Nordic hamstring curl programme improves change of direction ability, despite no architectural, strength or speed adaptations in elite youth soccer players
Published in Research in Sports Medicine, 2022
James Siddle, Kristian Weaver, Matt Greig, Damian Harper, Christopher Michael Brogden
Muscle architecture characteristics, muscle thickness (MT), pennation angle (PA) and fascicle length (FL) of the biceps femoris long head (BFlh), semimembranosus (SM) and semitendinosus (ST) were assessed using two-dimensional B-mode ultrasound images (GE Healthcare, LOGIQ e R7, Wauwatosa, USA) taken along the longitudinal axis of each muscle belly (frequency 12 MHz; depth 8 cm; field of view 12.7 × 47 mm, probe L4-12 t) on the dominant limb. The participant lay in prone, with hip in a neutral position and the knee extended. The scanning site was determined as the mid-point between the ischial tuberosity and popliteal crease, along the line of the BFlh, SM and ST. Three ultrasound images were recorded and stored for analysis using ImageJ software. MT was determined as the distance between the intermediate and superficial aponeuroses, whilst PA was defined as the angle between a fascicle of interest and the inferior aponeuroses (Timmins et al., 2021). FL were reported in absolute terms relative to each measured muscle’s length. As the entire fascicle was not visible in the probe’s field of view, its length was estimated using the following equation (Kellis et al., 2009) (AA = aponeuroses angle):
Skeletal muscle properties and vascular function do not differ between healthy, young vegan and omnivorous men
Published in European Journal of Sport Science, 2022
Joe Page, Robert M. Erskine, Nicola D. Hopkins
Unlike vascular properties, to our knowledge, no previous study has investigated the effects of habitual vegan diet on skeletal muscle architecture. The VL muscle thickness and fascicle pennation angle values in our study were similar to those reported previously in similar populations (Erskine et al., 2010; Erskine et al., 2011; Franchi et al., 2018). We found no differences in VL thickness or fascicle pennation angle between vegans and omnivores, despite omnivores consuming a higher daily protein intake compared with vegans. This is surprising, given plant-based sources of protein, such as wheat and soy, fail to stimulate muscle protein synthesis to the same extent as some animal protein sources (e.g. whey protein) (Gorissen et al., 2016; Tang, Moore, Kujbida, Tarnopolsky, & Phillips, 2009). However, it has been demonstrated that gains in lean body mass and muscular strength are similar in response to supplementation with either soy or animal protein sources (Messina, Lynch, Dickinson, & Reed, 2018). Therefore, although the quality of protein might be important for efficient delivery of amino acids to the muscle following resistance exercise (thereby potentially maximising the muscle hypertrophic response in athletes), it may not be so important in non-resistance trained individuals. Furthermore, although vegans consumed less protein than omnivores in our study, they still consumed 0.9 g/kg/d protein, which is within the recommended range for daily protein intake (0.8–2 g/kg/d) (Thomas, Erdman, & Burke, 2016), thus potentially explaining the similar muscle size and architecture between our vegans and omnivores.