scholarly journals Musculoskeletal modelling of the Nile crocodile ( Crocodylus niloticus ) hindlimb: Effects of limb posture on leverage during terrestrial locomotion

2021 ◽  
Author(s):  
Ashleigh L. A. Wiseman ◽  
Peter J. Bishop ◽  
Oliver E. Demuth ◽  
Andrew R. Cuff ◽  
Krijn B. Michel ◽  
...  
Keyword(s):  
Musculoskeletal Modelling ◽  
Terrestrial Locomotion ◽  
Limb Posture ◽  
Nile Crocodile

Nile crocodile is two species

Nature ◽  
2011 ◽  
Author(s):  
Ed Yong
Keyword(s):  
Nile Crocodile

The hominin lineage

2017 ◽  
Author(s):  
Francisco J. Ayala ◽  
Camilo J. Cela-Conde
Keyword(s):  
Rift Valley ◽  
Climate Changes ◽  
Human Lineage ◽  
Terrestrial Locomotion ◽  
Geological Formations ◽  
Difficult Issue ◽  
Human Fossils

This chapter describes the origin of the human lineage within the evolution of the hominoids, which raises the difficult issue of how to integrate the evolution of dentition and terrestrial locomotion. Next is the investigation of the appearance and initial dispersal of the hominins toward the end of the Miocene, with particular attention to the models of colonization of new territories as a function of climate changes. The hypothesis of the adaptation to the open savanna by bipedalism is explored. Finally, there is a summary description of the different deposits and localities of the main African localities with human fossils, pointing out the different geological formations and exemplars found in each deposit, including two sites north of the Rift Valley of great importance: Toros-Menalla (Tchad) and Dmanisi (Georgia).

Differences in muscular activation and fatigue for intermittent and constant load

2005 ◽  
Vol 5 (1) ◽  
pp. 43-56
Author(s):  
Danuta Roman-Liu ◽  
Krzysztof Kȩdzior
Keyword(s):  
External Force ◽  
Upper Limb ◽  
Muscle Activation ◽  
Regression Line ◽  
Constant Load ◽  
Median Frequency ◽  
Experimental Conditions ◽  
Emg Signal ◽  
Limb Posture ◽  
Muscular Activation

The aim of this study was to compare the influence of constant or intermittent load on muscle activation and fatigue. The analysis and assessment of muscular activation and fatigue was based on surface EMG measurements from eight muscles (seven muscles of the right upper limb and trapezius muscle). Two EMG signal parameters were analyzed for each of the experimental conditions distinguished by the value of the external force and the character of the load – constant or intermittent. The amplitude related to its maximum (AMP) and the slope of the regression line between time and median frequency (SMF) were the EMG parameters that were analyzed. The results showed that constant load caused higher muscular fatigue than intermittent load despite the lower value of the external force and lower muscle activation. Results suggest that additional external force might influence muscle activation and fatigue more than upper limb posture. The results of the study support the thesis that all biomechanical factors which influence upper limb load and fatigue (upper limb posture, external force and time sequences) should be considered when work stands and work processes are designed. They also indicate that constant load should be especially avoided.

scholarly journals Exploring the functional morphology of the Gorilla shoulder through musculoskeletal modelling

2021 ◽  
Author(s):  
Julia van Beesel ◽  
John R. Hutchinson ◽  
Jean‐Jacques Hublin ◽  
Stephanie M. Melillo
Keyword(s):  
Functional Morphology ◽  
Musculoskeletal Modelling

Dynamic Splints, Functionally-Customized With Nitinol, Can Reduce Joint Rigidity in Pediatric Subjects With Spasticity

2013 ◽  
Author(s):  
Lorenzo Garavaglia ◽  
Elena Beretta ◽  
Sandra Strazzer ◽  
Felice Sala ◽  
Morena Delle Fave ◽  
...  
Keyword(s):  
Niti Alloy ◽  
Neuromuscular Diseases ◽  
Contact Forces ◽  
Muscle Rigidity ◽  
Cortical Function ◽  
Paretic Limb ◽  
Limb Posture ◽  
Joint Rigidity ◽  
Complex Phenomena

Neuromuscular diseases as a consequence of brain damage are complex phenomena involving disuse, immobility, brain tissue remodeling and cortical function remapping. They may have various causes and strike any part of the population. The vicious circle leading to a worsening of the patients’ conditions proceeds through muscle shortening by contractures, disruption of the normal reflex behavior and sensory problems, development of spasticity [1]. Physical rehabilitation alone or in association with surgery or pharmacological treatments can be useful in limiting those degenerations. Besides manual rehabilitation, splints and braces are prescribed to control the limb posture and obtain stretching of the muscles. The role of those orthoses is to maintain the paretic limb in a set ‘physiological’ position and let it relax into that posture, in an attempt to reduce muscle rigidity and contractures. However applying a fixed constraint to the limb and waiting for relaxation to take place, may cause discomfort, pain, skin rash, and sundry different complications [2]. Also, any residual voluntary movement is prevented by a fixed-angle splinting. In addition, all these negative characteristics limit tolerability and daily application times. This work presents a different way to promote limb repositioning, based on the application of NiTi-alloy-based dynamic splints, which favor mobility and any residual use of the affected limb. Furthermore it suggests that application of mild contact forces prolonged in time has the advantage of feeling less painful and uncomfortable for the patients, improving overall treatment tolerability.

Concurrent prediction of ground reaction forces and moments and tibiofemoral contact forces during walking using musculoskeletal modelling

2018 ◽  
Vol 52 ◽  
pp. 31-40 ◽  
Author(s):  
Yinghu Peng ◽  
Zhifeng Zhang ◽  
Yongchang Gao ◽  
Zhenxian Chen ◽  
Hua Xin ◽  
...  
Keyword(s):  
Contact Forces ◽  
Ground Reaction Forces ◽  
Musculoskeletal Modelling ◽  
Reaction Forces

scholarly journals Body size and lower limb posture during walking in humans

PLoS ONE ◽  
2017 ◽  
Vol 12 (2) ◽  
pp. e0172112 ◽  
Author(s):  
Martin Hora ◽  
Libor Soumar ◽  
Herman Pontzer ◽  
Vladimír Sládek
Keyword(s):  
Body Size ◽  
Lower Limb ◽  
Limb Posture

The Role of the ‘Walking Legs’ in Aquatic and Terrestrial Locomotion of the Crayfish Austropotamobius Pallipes (Lereboullet)

1975 ◽  
Vol 62 (2) ◽  
pp. 447-454 ◽  
Author(s):  
CAROLINE M. POND
Keyword(s):  
The Body ◽  
Hydrodynamic Drag ◽  
Terrestrial Locomotion ◽  
Austropotamobius Pallipes ◽  
The Third ◽  
Fourth Pair

1. The hydrodynamic drag acting on the crayfish Austropotamobius pallipes is measured and it is concluded that, in the range of velocities used in walking, the drag is independent of the posture of the limbs and the direction of motion of the body. At swimming velocities the streamlining caused by promotion of the legs reduces the drag losses to half that of a crayfish moving in the forwards walking posture at the same speed. 2. The forwards walking of intact crayfish is compared with that of the same animal after amputation of one or more pairs of legs. It is concluded that the third and fourth pair of legs provide most of the propulsion under water and the second pair is not essential to locomotion under any of the conditions tried.

Warm-blooded isochore structure in Nile crocodile and turtle

1999 ◽  
Vol 16 (11) ◽  
pp. 1521-1527 ◽  
Author(s):  
S. Hughes ◽  
D. Zelus ◽  
D. Mouchiroud
Keyword(s):  
Nile Crocodile
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