Article

Muscle dimension of the upper limb in the orangutan

Department of Anatomy 1st, School of Veterinary Medicine, Azabu University, Kanagawa, 229-8501, Japan.
Primates (Impact Factor: 1.34). 04/2008; 49(3):204-9. DOI: 10.1007/s10329-008-0082-5
Source: PubMed

ABSTRACT

We dissected the left upper limb of a female orangutan and systematically recorded muscle mass, fascicle length, and physiological cross-sectional area (PCSA), in order to quantitatively clarify the unique muscle architecture of the upper limb of the orangutan. Comparisons of the musculature of the dissected orangutan with corresponding published chimpanzee data demonstrated that in the orangutan, the elbow flexors, notably M. brachioradialis, tend to exhibit greater PCSAs. Moreover, the digital II-V flexors in the forearm, such as M. flexor digitorum superficialis and M. flexor digitorum profundus, tend to have smaller PCSA as a result of their relatively longer fascicles. Thus, in the orangutan, the elbow flexors demonstrate a higher potential for force production, whereas the forearm muscles allow a greater range of wrist joint mobility. The differences in the force-generating capacity in the upper limb muscles of the two species might reflect functional specialization of muscle architecture in the upper limb of the orangutan for living in arboreal environments.

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    • "The muscle architecture summarises all microstructural conditions, such as fibre length, fibre number, or pennation angle inside the muscle. To determine those parameters, a number of studies on various mammalian species reaching from humans (Kawakami et al., 1995; Chow et al., 2000; Lieber and Fridén, 2000; Blazevich et al., 2006, 2007; Ward et al., 2009; Kellis et al., 2009, 2010) and monkeys (Roy et al., 1984a; Carlson, 2006; Payne et al., 2006; Oishi et al., 2008; Ogihara et al., 2009) over cats (Spector et al., 1980; Sacks and Roy, 1982; Loeb et al., 1987) and mice/rats (Roy et al., 1984b; Burkholder et al., 1994; Eng et al., 2008; Mathewson et al., 2012) to guinea pigs (Roy et al., 1984b; Powell et al., 1984) and rabbits (Roy et al., 1984b; Lieber and Blevins, 1989; Schenk et al., 2013) have been conducted to demonstrate the specialisations of muscles based on their functions. In the aforementioned studies, from a mechanical perspective, skeletal muscle architecture is specified by a low number of single intrinsic parameters wherein the fibre length, cross-sectional area, and mean pennation angle are directly correlated to the generated muscle force (Azizi et al., 2008). "
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    ABSTRACT: There are several studies dealing with experimental and structural analyses of skeletal muscles that are aimed at gaining a better understanding of three-dimensional muscle deformation and force generation. A variety of these contributions have performed structural or mechanical analyses, but very few have combined these approaches at different levels. To fill this gap, the present study aims to bring together three-dimensional micro-structural and mechanical findings in rabbit M. plantaris to study load transfer mechanisms inside the muscle during passive loading and active muscle contraction. During these two deformation states, the three-dimensional surface of the aponeurosis-tendon complex was recorded using optical measurement systems. In this way, the strain distribution on the muscle can be calculated to interpret the load transfer mechanisms inside the muscle. The results show that the three-dimensional strain distribution during muscle activation is completely different from the distribution during passive loading. Under both loading conditions, the strain distribution is irregular. To interpret these findings, the gross try and the fascicle architecture of the M. plantaris were determined. In doing so, a highly complex microstructure featuring tube- and sail-like structure was identified. Moreover, a compartmentalisation of the muscle into two compartments was detected. The smaller, bipennated muscle compartment was embedded into the larger, unipennated compartment. To the authors׳ knowledge, this type of inner structure has never been previously documented in single-headed muscles. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Full-text · Article · Jul 2015 · Journal of the Mechanical Behavior of Biomedical Materials
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    • "The muscle architecture summarises all microstructural conditions, such as fibre length, fibre number, or pennation angle inside the muscle. To determine those parameters, a number of studies on various mammalian species reaching from humans (Kawakami et al., 1995; Chow et al., 2000; Lieber and Fridén, 2000; Blazevich et al., 2006, 2007; Ward et al., 2009; Kellis et al., 2009, 2010) and monkeys (Roy et al., 1984a; Carlson, 2006; Payne et al., 2006; Oishi et al., 2008; Ogihara et al., 2009) over cats (Spector et al., 1980; Sacks and Roy, 1982; Loeb et al., 1987) and mice/rats (Roy et al., 1984b; Burkholder et al., 1994; Eng et al., 2008; Mathewson et al., 2012) to guinea pigs (Roy et al., 1984b; Powell et al., 1984) and rabbits (Roy et al., 1984b; Lieber and Blevins, 1989; Schenk et al., 2013) have been conducted to demonstrate the specialisations of muscles based on their functions. In the aforementioned studies, from a mechanical perspective, skeletal muscle architecture is specified by a low number of single intrinsic parameters wherein the fibre length, cross-sectional area, and mean pennation angle are directly correlated to the generated muscle force (Azizi et al., 2008). "
    [Show abstract] [Hide abstract]
    ABSTRACT: There are several studies dealing with experimental and structural analyses of skeletal muscles that are aimed at gaining a better understanding of three-dimensional muscle deformation and force generation. A variety of these contributions have performed structural or mechanical analyses, but very few have combined these approaches at different levels. To fill this gap, the present study aims to bring together three-dimensional micro-structural and mechanical findings in rabbit M. plantaris to study load transfer mechanisms inside the muscle during passive loading and active muscle contraction. During these two deformation states, the three-dimensional surface of the aponeurosis-tendon complex was recorded using optical measurement systems. In this way, the strain distribution on the muscle can be calculated to interpret the load transfer mechanisms inside the muscle. The results show that the three-dimensional strain distribution during muscle activation is completely different from the distribution during passive loading. Under both loading conditions, the strain distribution is irregular. To interpret these findings, the gross try and the fascicle architecture of the M. plantaris were determined. In doing so, a highly complex microstructure featuring tube- and sail-like structure was identified. Moreover, a compartmentalisation of the muscle into two compartments was detected. The smaller, bipennated muscle compartment was embedded into the larger, unipennated compartment. To the authors knowledge, this type of inner structure has never been previously documented in single-headed muscles.
    Full-text · Article · Jul 2015 · Journal of the Mechanical Behavior of Biomedical Materials
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    • "Mass and PCSA Potau et al., 2009 3 c Mass Pongo Oishi et al., 2008 1 Mass and PCSA Oishi et al., 2009 2 Mass and PCSA Potau et al., 2009 2 c Mass Zihlman et al., 2011 3 Mass Homo Veeger et al., 1991 9 d Mass and PCSA Potau et al., 2009 30 c Mass Keating et al., 1993 5 PCSA Gorilla Zihlman et al., 2011 5 "
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