Determinants of work produced by skeletal muscle: potential limitations of activation and relaxation

Caiozzo, Vincent J.; Baldwin, K. M.

doi:10.1152/ajpcell.1997.273.3.c1049

Cited by 57 publications

(62 citation statements)

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“…Small differences in intrinsic contractile properties such as twitch and tetanus times and maximal shortening velocities (Fig.·3) do not necessarily have biological relevance (Caizzo and Baldwin, 1997;James et al, 1996). However, the recorded times to peak twitch force and times to half peak tetanus force (Fig.·3) were significantly correlated with the cycle frequencies for optimal power output in our data (N=40, r 2 =0.41 and 0.35, respectively, P<0.0001).…”

Section: Discussionmentioning

confidence: 47%

Scaling of contractile properties of catfish feeding muscles

Wassenbergh

Herrel

James

et al. 2007

Journal of Experimental Biology

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Biomechanical models are intrinsically limited in explaining the ontogenetic scaling relationships for prey capture kinematics in aquatic vertebrates because no data are available on the scaling of intrinsic contractile properties of the muscles that power feeding. However, functional insight into scaling relationships is fundamental to our understanding of the ecology, performance and evolution of animals. In this study, in vitro contractile properties of three feeding muscles were determined for a series of different sizes of African air-breathing catfishes (Clarias gariepinus). These muscles were the mouth closer musculus adductor mandibulae A2A3′, the mouth opener m. protractor hyoidei and the hypaxial muscles responsible for pectoral girdle retraction. Tetanus and twitch activation rise times increased significantly with size, while latency time was size independent. In accordance with the decrease in feeding velocity with increasing size, the cycle frequency for maximal power output of the protractor hyoidei and the adductor mandibulae showed a negative scaling relationship. Theoretical modelling predicts a scaling relationship for in vivo muscle function during which these muscles always produced at least 80% of their maximal in vitro power. These findings suggest that the contractile properties of these feeding muscles are fine-tuned to the changes in biomechanical constraints of movement of the feeding apparatus during ontogeny. However, each muscle appears to have a unique set of contractile properties. The hypaxials, the most important muscle for powering suction feeding in clariid catfish, differed from the other muscles by generating higher maximal stress and mass-specific power output with increased size,whilst the optimum cycle frequency for maximal power output only decreased significantly with size in the larger adults (cranial lengths greater than 60 mm).

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Section: Discussionmentioning

confidence: 47%

Scaling of contractile properties of catfish feeding muscles

Wassenbergh

Herrel

James

et al. 2007

Journal of Experimental Biology

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“…We do not know the maximal shortening velocity of L. nasuta plantaris longus muscle, but previous experimental modeling of work loops suggests that the value will be relatively high compared with other anurans Lichtwark and Wilson 2005). However, previous studies also indicate that the intrinsic contractile properties measured in isometric and force velocity studies are not always good indicators of the likely power output that can be produced under work loop conditions Caizzo and Baldwin 1997). The relatively high optimal cycle frequency for power output achieved in L. nasuta plantaris longus muscle also suggests that this muscle is of a relatively fast fiber type, probably containing more muscle fibers with type I myosin heavy chain and/or other fast muscle protein isoforms (such as myosin light chains) than other frog muscles (Lutz et al 1998;Andruchova et al 2006).…”

Section: Muscle Mechanicsmentioning

confidence: 90%

Explosive Jumping: Extreme Morphological and Physiological Specializations of Australian Rocket Frogs (Litoria nasuta)

James

Wilson

2008

Physiological and Biochemical Zoology

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JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. The University of Chicago Press ABSTRACTAnuran jumping is an ideal system for examining the relationships between key morphological, physiological, and kinematic parameters. We used the Australian rocket frog (Litoria nasuta) as a model species to investigate extreme specialization of the vertebrate locomotor system for jumping. We measured the ground reaction forces applied during maximal jumps using a custom-designed force platform, which allowed us to calculate instantaneous measures of acceleration, velocity, power output, and total jump distance. We quantified the mechanical properties of the plantaris longus muscle using the work loop technique. We found that L. nasuta achieved the second-longest relative jumping distance for any anuran (55.2 body lengths for one individual) and the highest published anuran values for isolated net mean muscle power output measured using work loops (93.5 W kg Ϫ1 muscle mass), hindlimb length to snout-vent length ratio (2.02), and relative hindlimb muscle mass (33% of body mass). Litoria nasuta also had a higher ratio of tibia length to snout-vent length than 19 related species. We found that the mean power output expended during the takeoff phase of jumping in the individual that jumped the farthest was about three times greater than our estimate of available muscle power output.

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“…It has been speculated that pedalling cadences greater than 165 rpm would surpass the maximum shortening velocity of the slow muscle fibres (Sargeant and Beelen, 1993) and as deactivation is longer than activation, during the activation-deactivation cycle of muscle contraction (Buchthal et al, 1973;Burke et al, 1973;Lee et al, 2011) the highest cycle frequencies in this study may exceed the relaxation capabilities of the slowest muscle fibres. The short excitation durations can partially be explained by the ability of the muscle to reach higher cycle frequencies because active shortening accelerates the relaxation dynamics expected from isometric twitches (Caiozzo and Baldwin, 1997;Askew and Marsh, 1998). As noted, the EMG frequency analysis indicated that there was also some manipulation of the timing of muscle fibre recruitment relative to muscle excitation that may have helped enable the slow fibres to participate at such high cycle frequencies.…”

Section: Research Articlementioning

confidence: 99%

Early deactivation of slower muscle fibres at high movement frequencies

Blake

Wakeling

2014

Journal of Experimental Biology

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Animals produce rapid movements using fast cyclical muscle contractions. These types of movements are better suited to faster muscle fibres within muscles of mixed fibre types as they can shorten at faster velocities and achieve higher activation-deactivation rates than their slower counterparts. Preferential recruitment of faster muscle fibres has previously been shown during high velocity contractions. Additionally, muscle deactivation takes longer than activation and therefore may pose a limitation to fast cyclical contractions. It has been speculated that slower fibres may be deactivated before faster fibres to accommodate their longer deactivation time. This study aimed to test whether shifts in muscle fibre recruitment occur with derecruitment of slow fibres before faster fibres at high cycle frequencies. Electromyographic (EMG) signals were collected from the medial gastrocnemius at an extreme range of cycle frequencies and workloads. Wavelets were used to resolve the EMG signals into time and frequency space and the primary sources of variability within the EMG frequency spectra were identified through principal component analysis. Early derecruitment of slower fibres was evident at the end of muscle excitation at higher cycle frequencies, as determined by reduced low-frequency EMG content, and additional slower fibre recruitment was present at the highest cycle frequency. The duration of muscle excitation reached a minimum of about 150 ms and did not change for the three highest cycle frequencies, suggesting a duration limit for the medial gastrocnemius. This study provides further evidence of modifications of muscle fibre recruitment strategies to meet the mechanical demands of movement.

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Determinants of work produced by skeletal muscle: potential limitations of activation and relaxation

Cited by 57 publications

References 0 publications

Scaling of contractile properties of catfish feeding muscles

Scaling of contractile properties of catfish feeding muscles

Explosive Jumping: Extreme Morphological and Physiological Specializations of Australian Rocket Frogs (Litoria nasuta)

Early deactivation of slower muscle fibres at high movement frequencies

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