Architectural Properties of Sloth Forelimb Muscles (Pilosa: Bradypodidae)

@article{Olson2017ArchitecturalPO,
  title={Architectural Properties of Sloth Forelimb Muscles (Pilosa: Bradypodidae)},
  author={Rachel A. Olson and Z. D. Glenn and Rebecca N. Cliffe and Michael T. Butcher},
  journal={Journal of Mammalian Evolution},
  year={2017},
  volume={25},
  pages={573-588}
}
Tree sloths have reduced skeletal muscle mass, and yet they are able to perform suspensory behaviors that require both strength and fatigue resistance to suspend their body mass for extended periods of time. The muscle architecture of sloths is hypothesized to be modified in ways that will enhance force production to compensate for this reduction in limb muscle mass. Our objective is to test this hypothesis by quantifying architecture properties in the forelimb musculature of the brown-throated… Expand

Figures and Tables from this paper

Myosin fiber type distribution and metabolic characteristics in the hindlimb muscles of sloths (Xenarthra: Pilosa)
TLDR
These findings emphasize joint stabilization in the hindlimb during suspensory habits, most notably in three-toed sloths, and imply that two-toe sloths are capable of faster muscle contraction as a potential compensatory mechanism for increasing joint power. Expand
Cheap labor: myosin fiber type expression and enzyme activity in the forelimb musculature of sloths (Pilosa: Xenarthra).
TLDR
It is suggested that sloth forelimb muscles may rely heavily on rapid ATP resynthesis pathways, and lactate accumulation may be beneficial as means to systemically conserve energy. Expand
Keep calm and hang on: EMG activation in the forelimb musculature of three-toed sloths (Bradypus variegatus)
TLDR
The hypothesis is that three-toed sloths may selectively recruit smaller, fast motor units for suspensory postures but have the ability to offset the cost of force production by recruitment of large, slow motor units during locomotion. Expand
A Horse of a Different Color?: Tensile Strength and Elasticity of Sloth Flexor Tendons.
Tendons must be able to withstand the tensile forces generated by muscles to provide support while avoiding failure. The properties of tendons in mammal limbs must therefore be appropriate toExpand
Hind Foot Drumming: Muscle Architecture of the Hind Limb in Three Bathyergidae Species
TLDR
The internal structure of 32 hind limb muscles was evaluated in two drumming and one non-drumming species of Bathyergidae, finding that M . Expand
Coming to grips with life upside down: how myosin fiber type and metabolic properties of sloth hindlimb muscles contribute to suspensory function
TLDR
A joint stabilization role by the hindlimbs during suspension, especially in smaller three-toed sloths, is emphasized, and modifications to muscle metabolism rather than MHC expression may be more reflective of functional adaptation in sloth limbs. Expand
Architectural properties of the musculoskeletal system in the shoulder of two callitrichid primate species derived from virtual dissection
TLDR
There were only slight differences between species in regard to muscle lengths and moment arms, which suggests that these properties are not dependent on the preferred locomotor mode. Expand
Comparative forelimb myology and muscular architecture of a juvenile Malayan tapir (Tapirus indicus)
TLDR
This quantitative dataset of muscle architecture in a functionally tetradactyl perissodactyl is a pivotal first step towards reconstructing the locomotor capabilities of extinct, four‐toed ancestors of modern perissdactyls, and providing further insights into the equid locomotor transition. Expand
A suspensory way of life: Integrating locomotion, postures, limb movements, and forces in two‐toed sloths Choloepus didactylus (Megalonychidae, Folivora, Pilosa)
TLDR
This study integrated positional activities in naturalistic conditions with kinematic and kinetic observations collected on a simulated runway to best capture the biomechanical behavior of Linnaeus's two-toed sloths to gain a comprehensive understanding of the functional-adaptive profile of a particular species. Expand
Evolutionary adaptations in the flexor digitorum profundus muscle in Tamandua mexicana (Xenarthra, Myrmecophagidae)
TLDR
The flexor digitorum profundus muscle is highly developed in Tamandua and occupies the caudal part of the arm and forearm, which is an evolutionary adaptation that could have occurred during evolution from the common ancestor of TamandUA and Myrmecophaga. Expand
...
1
2
...

References

SHOWING 1-10 OF 65 REFERENCES
Forelimb muscle architecture and myosin isoform composition in the groundhog (Marmota monax)
TLDR
Overall, the forelimb musculature of the groundhog is capable of relatively low sustained force and power, and these properties are consistent with the findings of a predominant expression of the MHC-2A isoform. Expand
Functional anatomy of the cheetah (Acinonyx jubatus) forelimb
TLDR
The musculoskeletal anatomy of the cheetah forelimb is described and quantify and it is suggested that this limb is resisting large ground reaction force joint torques and therefore is not functioning as a simple strut during the high‐speed manoeuvring in hunting. Expand
Functional anatomy of the cheetah (Acinonyx jubatus) hindlimb
TLDR
It is proposed that the cheetah powers acceleration using its extensive back musculature, which possesses several unique adaptations for high‐speed locomotion and fast accelerations, when compared to the racing greyhound. Expand
Architectural specialization of the intrinsic thoracic limb musculature of the American badger (Taxidea taxus)
TLDR
The findings support the hypothesis and indicate that forelimb muscle architecture is consistent with specializations for scratch‐digging, and Quantified muscle properties in the American badger serve as a comparator to evaluate the range of diversity in muscle structure and contractile function that exists in mammals specialized for fossorial habits. Expand
Functional specialisation of the pelvic limb of the hare (Lepus europeus)
TLDR
The pelvic limb of the hare was found to contain substantial amounts of hip extensor and adductor/abductor muscle volume, which is likely to be required for power production and stability during rapid turning. Expand
Skeletal muscle architecture of the rabbit hindlimb: Functional implications of muscle design
TLDR
Differences were observed between plantarflexors and dorsiflexors, which have architectural features that suit them for force production and excursion respectively, which represented clear morphological distinctions that have functional consequences. Expand
Muscle architecture and out‐force potential of the thoracic limb in the eastern mole (Scalopus aquaticus)
TLDR
Moles have several specializations of their digging apparatus that greatly enhance the application of out‐force, and these morphological features suggest convergence on limb form and burrowing function between New and Old World moles. Expand
Functional specialisation of the thoracic limb of the hare (Lepus europeus)
TLDR
The Subscapularis muscle was capable of generating surprisingly high forces, suggesting that the hare must be able to withstand/produce high forces during activities that need medio‐lateral stability, such as turning. Expand
Anatomy of raccoon (Procyon lotor) and coati (Nasua narica and N. nasua) forearm and leg muscles: Relations between fiber length, moment‐arm length, and joint‐angle excursion
Muscle architecture, moment arms, and locomotor movements in the distal limb segments of the procyonids Nasua (coati) and Procyon (raccoon) are analyzed with reference to patterns of muscle fiberExpand
Architecture of the hind limb muscles of cats: Functional significance
TLDR
Rations of wet weight to predicted maximal tetanic tension for each muscle and group were calculated to compare the relative priority of muscle force versus muscle length‐velocity for a given mass of muscle, suggesting that velocity and/or displacement is a priority for the hamstrings, whereas force is apriority for the quadriceps and lower leg muscles. Expand
...
1
2
3
4
5
...