Analysis of the moment arms and kinematics of ostrich (Struthio camelus) double patellar sesamoids

2017 ◽  
Vol 327 (4) ◽  
pp. 163-171 ◽  
Author(s):  
Sophie Regnault ◽  
Vivian R. Allen ◽  
Kyle P. Chadwick ◽  
John R. Hutchinson
Keyword(s):  
Struthio Camelus ◽  
Moment Arms ◽  
The Moment

scholarly journals Musculoskeletal modeling of an ostrich (Struthio camelus) pelvic limb: Influence of limb orientation on muscular capacity during locomotion

2014 ◽  
Author(s):  
John R Hutchinson ◽  
Jeffery W Rankin ◽  
Jonas Rubenson ◽  
Kate H Rosenbluth ◽  
Robert A Siston ◽  
...  
Keyword(s):  
Muscle Function ◽  
Sagittal Plane ◽  
Dynamic Properties ◽  
Three Dimensional ◽  
Limb Muscle ◽  
Struthio Camelus ◽  
Moment Arms ◽  
Extensor Muscles ◽  
Pelvic Limb ◽  
The Moment

We developed a three-dimensional, biomechanical computer model of the 36 major pelvic limb muscle groups in an ostrich (Struthio camelus) to investigate muscle function in this, the largest of extant birds and model organism for many studies of locomotor mechanics, body size, anatomy and evolution. Combined with experimental data, we use this model to test two main hypotheses. We first query whether ostriches use limb orientations (joint angles) that optimize the moment-generating capacities of their muscles during walking or running. Next, we test whether ostriches use limb orientations at mid-stance that keep their extensor muscles near maximal, and flexor muscles near minimal, moment arms. Our two hypotheses relate to the control priorities that a large bipedal animal might evolve under biomechanical constraints to achieve more effective static weight support. We find that ostriches do not use limb orientations to optimize the moment-generating capacities or moment arms of their muscles. We infer that dynamic properties of muscles or tendons might be better candidates for locomotor optimization. Regardless, general principles explaining why species choose particular joint orientations during locomotion are lacking, raising the question of whether such general principles exist or if clades evolve different patterns (e.g. weighting of muscle force-length or force-velocity properties in selecting postures). This leaves theoretical studies of muscle moment arms estimated for extinct animals at an impasse until studies of extant taxa answer these questions. Finally, we compare our model’s results against those of two prior studies of ostrich limb muscle moment arms, finding general agreement for many muscles. Some flexor and extensor muscles exhibit self-stabilization patterns (posture-dependent switches between flexor/extensor action) that ostriches may use to coordinate their locomotion. However, some conspicuous areas of disagreement in our results illustrate some cautionary principles. Importantly, tendon-travel empirical measurements of muscle moment arms must be carefully designed to preserve 3D muscle geometry lest their accuracy suffer relative to that of anatomically realistic models. The dearth of accurate experimental measurements of 3D moment arms of muscles in birds leaves uncertainty regarding the relative accuracy of different modelling or experimental datasets such as in ostriches. Our model, however, provides a comprehensive set of 3D estimates of muscle actions in ostriches for the first time, emphasizing that avian limb mechanics are highly three-dimensional and complex, and how no muscles act purely in the sagittal plane. A comparative synthesis of experiments and models such as ours could provide powerful synthesis into how anatomy, mechanics and control interact during locomotion and how these interactions evolve. Such a framework could remove obstacles impeding the analysis of muscle function in extinct taxa.

scholarly journals Musculoskeletal modeling of an ostrich (Struthio camelus) pelvic limb: Influence of limb orientation on muscular capacity during locomotion

2014 ◽  
Author(s):  
John R Hutchinson ◽  
Jeffery W Rankin ◽  
Jonas Rubenson ◽  
Kate H Rosenbluth ◽  
Robert A Siston ◽  
...  
Keyword(s):  
Muscle Function ◽  
Sagittal Plane ◽  
Dynamic Properties ◽  
Three Dimensional ◽  
Limb Muscle ◽  
Struthio Camelus ◽  
Moment Arms ◽  
Extensor Muscles ◽  
Pelvic Limb ◽  
The Moment

We developed a three-dimensional, biomechanical computer model of the 36 major pelvic limb muscle groups in an ostrich (Struthio camelus) to investigate muscle function in this, the largest of extant birds and model organism for many studies of locomotor mechanics, body size, anatomy and evolution. Combined with experimental data, we use this model to test two main hypotheses. We first query whether ostriches use limb orientations (joint angles) that optimize the moment-generating capacities of their muscles during walking or running. Next, we test whether ostriches use limb orientations at mid-stance that keep their extensor muscles near maximal, and flexor muscles near minimal, moment arms. Our two hypotheses relate to the control priorities that a large bipedal animal might evolve under biomechanical constraints to achieve more effective static weight support. We find that ostriches do not use limb orientations to optimize the moment-generating capacities or moment arms of their muscles. We infer that dynamic properties of muscles or tendons might be better candidates for locomotor optimization. Regardless, general principles explaining why species choose particular joint orientations during locomotion are lacking, raising the question of whether such general principles exist or if clades evolve different patterns (e.g. weighting of muscle force-length or force-velocity properties in selecting postures). This leaves theoretical studies of muscle moment arms estimated for extinct animals at an impasse until studies of extant taxa answer these questions. Finally, we compare our model’s results against those of two prior studies of ostrich limb muscle moment arms, finding general agreement for many muscles. Some flexor and extensor muscles exhibit self-stabilization patterns (posture-dependent switches between flexor/extensor action) that ostriches may use to coordinate their locomotion. However, some conspicuous areas of disagreement in our results illustrate some cautionary principles. Importantly, tendon-travel empirical measurements of muscle moment arms must be carefully designed to preserve 3D muscle geometry lest their accuracy suffer relative to that of anatomically realistic models. The dearth of accurate experimental measurements of 3D moment arms of muscles in birds leaves uncertainty regarding the relative accuracy of different modelling or experimental datasets such as in ostriches. Our model, however, provides a comprehensive set of 3D estimates of muscle actions in ostriches for the first time, emphasizing that avian limb mechanics are highly three-dimensional and complex, and how no muscles act purely in the sagittal plane. A comparative synthesis of experiments and models such as ours could provide powerful synthesis into how anatomy, mechanics and control interact during locomotion and how these interactions evolve. Such a framework could remove obstacles impeding the analysis of muscle function in extinct taxa.

Analysis of the mero-carpopodite joint of the American lobster and snow crab. II. Kinematics, morphometrics and moment arms

2003 ◽  
Vol 83 (6) ◽  
pp. 1249-1259 ◽  
Author(s):  
S.C. Mitchell ◽  
M.E. DeMont
Keyword(s):  
Joint Angle ◽  
Snow Crab ◽  
Moment Arm ◽  
Scaling Effects ◽  
Joint Angles ◽  
Positive Allometry ◽  
Moment Arms ◽  
Arm Reaching ◽  
Flexion Extension ◽  
The Moment

This research reports on the kinematics of lobster and snow crab walking, documents changes in the moment arms of the mero-carpopodite joint during rotation, and examines scaling effects of morphological and mechanical variables in these crustacean species. Forward walking lobsters and lateral walking crabs were recorded and images analysed to describe the kinematics of these animals, and subsequently morphometric and moment arm measurements made. During forward walking the lobster maintains fixed mero-carpopodite joint angles during both the power and recovery strokes, though each of the walking legs maintains different joint angles. Legs 3 and 5 are maintained at angles which appear to equalize the flexor and extensor moment arms, and leg 4 joint angle appears to maximize the extensor moment arm. The snow crab has a joint excursion angle of between approximately 50° to 150° and, during flat bed walking, the leading and trailing legs move through similar excursion angles. The length of the meropodite for both species are longer for the anterior two leg pairs relative to the posterior two pairs and the rate of growth of the meropodite is largely isometric for the lobster while consistently increases with positive allometry in the crab. The flexor and extensor moment arms generated as the joint undergoes flexion/extension show two distinct patterns with the extensor moment arm being maximized at relatively low joint angles (55°–115°) and the flexor moment arm reaching a plateau at joint extension with angles between 95° and 155°. The flexor apodeme possesses the largest moment arms in all legs for both species, suggesting the flexors are able to generate greater torques. It appears that, mechanically, these laterally moving animals may be ‘pulling’ with the leading legs to a greater extent than ‘pushing’ with the trailing legs.

scholarly journals A comparison of the moment arms of pelvic limb muscles in horses bred for acceleration (Quarter Horse) and endurance (Arab)

2010 ◽  
Vol 217 (1) ◽  
pp. 26-37 ◽  
Author(s):  
T. C. Crook ◽  
S. E. Cruickshank ◽  
C. M. McGowan ◽  
N. Stubbs ◽  
A. M. Wilson ◽  
...  
Keyword(s):  
Moment Arms ◽  
Quarter Horse ◽  
Limb Muscles ◽  
Pelvic Limb ◽  
The Moment

Effects of Partially-Filled Containers in Dynamic Behavior of Tanker Trains Traveling on Curved Tracks

2008 ◽  
Author(s):  
Iman Hazrati Ashtiani ◽  
Davood Younesian ◽  
Mehrnoosh Abedi ◽  
Ebrahim Esmailzadeh
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Dynamic System ◽  
Dynamic Analysis ◽  
Parametric Study ◽  
Fluid Density ◽  
Moment Arms ◽  
Rail Irregularities ◽  
Curved Track ◽  
The Moment

Dynamic analysis of a partially-filled tanker train traveling on a curved track is studied in this paper. A partially-filled tanker is dynamically modeled when it is traveling along a real curved track. For three classes of tracks, rail irregularities are randomly generated by using Monte-Carlo simulation. An equivalent dynamic system is used to model sloshing motion of the fluid. Two derailment indexes i.e. derailment quotient and unloading ratio are obtained numerically as safety indicators. A parametric study is carried out to investigate how different parameters like the operational speed, fluid modeling, rail irregularities, and fluid density may affect the derailment potential. It is found that descending of the center of gravity and consequently reduction of the moment arms is more dominant than the oscillating forces due to sloshing motion.

Trapeziometacarpal Joint Instability Affects the Moment Arms of Thumb Motor Tendons

2000 ◽  
Vol 372 ◽  
pp. 262-271 ◽  
Author(s):  
Shohei Omokawa ◽  
Jaiyoung Ryu ◽  
Jin-Bo Tang ◽  
JunSoo Han ◽  
Vincent L. Kish
Keyword(s):  
Joint Instability ◽  
Trapeziometacarpal Joint ◽  
Moment Arms ◽  
The Moment

THE INFLUENCE OF THE NUMBER AND POSITION OF DOWELS ON THE BENDING MOMENT CAPACITY OF HEAT-TREATED WOOD DOWEL JOINTS

2021 ◽  
Vol 14(63) (1) ◽  
pp. 67-76
Author(s):  
Bogdan I. BEDELEAN ◽  
Iosif NECULĂEȘ ◽  
Cosmin G. SPÎRCHEZ ◽  
Sergiu RĂCĂȘAN
Keyword(s):  
Cross Section ◽  
Treated Wood ◽  
Bending Moment ◽  
Moment Capacity ◽  
Moment Arms ◽  
Heat Treated ◽  
Wood Dowel ◽  
Ultimate Failure ◽  
The Cross ◽  
The Moment

In this work, the influence of the number of dowels and the option to place the dowels in the cross section of part on the bending moment capacity of heat-treated wood dowel joints was analysed. The joints, which were made of heat-treated ash, were tested by means of a universal testing machine.The ultimate failure load and the moment arms were used to figure out the bending moment capacity of the joints loaded in compression or in tension. The number of dowels affected the tensile strength of the L-shaped heat-treated wood joints. The modality to place the dowels in the cross section of rail, namely, in collinearity or in a triangular shape, did not significantly affect the strength of the heat-treated wood dowel joints.

Changes in the moment arms of the rotator cuff and deltoid muscles with abduction and rotation.

1994 ◽  
Vol 76 (5) ◽  
pp. 667-676 ◽  
Author(s):  
J C Otis ◽  
C C Jiang ◽  
T L Wickiewicz ◽  
M G Peterson ◽  
R F Warren ◽  
...  
Keyword(s):  
Rotator Cuff ◽  
Moment Arms ◽  
The Moment

Impact of Individual Anatomy on the Benefit of cup Medialisation in Total Hip Arthroplasty

2016 ◽  
Vol 26 (6) ◽  
pp. 537-542 ◽  
Author(s):  
Alexandre Terrier ◽  
Valérie Parvex ◽  
Hannes A. Rüdiger
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Gluteus Medius ◽  
Femoral Anteversion ◽  
Patient Specific ◽  
Moment Arm ◽  
Total Hip ◽  
Moment Arms ◽  
The Moment ◽  
Anatomical Parameters

Introduction In total hip arthroplasty, cup medialisation with compensatory increase of femoral offset has been proposed to increase the moment arms of abductor muscles. However, this technique is associated with a loss of acetabular bone stock. Previous data indicates that the potential benefit is not constant among patients and is likely related to patient anatomy. Method Therefore, to be able to select patients who would benefit most from this technique, we measured several anatomical parameters of the pelvis and femur in 15 patients; and evaluated correlations between them and the changes of moment arms associated with cup medialisation. The anatomical measurements were performed on 3-D reconstructions of preoperative CT scans. The moment arms of the gluteus medius and gluteus minimus were calculated for an abduction and flexion movement using patient-specific finite element models. Results 6 anatomical parameters were correlated with muscle moment arm variations after cup medialisation. This effect was not systematic for either muscles or movements. Among all parameters, femoral anteversion was the most important parameter in explaining the effect of cup medialisation. Discussion Patients with small femoral anteversion or low-riding greater trochanter benefit more from cup medialisation in terms of moment arm increase in abduction motion.

scholarly journals A Hybrid Method for Computing Achilles Tendon Moment Arm Using Ultrasound and Motion Analysis

2010 ◽  
Vol 26 (2) ◽  
pp. 224-228 ◽  
Author(s):  
Kurt Manal ◽  
Justin D. Cowder ◽  
Thomas S. Buchanan
Keyword(s):  
Achilles Tendon ◽  
Motion Capture ◽  
Hybrid Method ◽  
Moment Arm ◽  
Measurement Instruments ◽  
Moment Arms ◽  
Perpendicular Distance ◽  
The Moment ◽  
Joint Center

In this article, we outline a method for computing Achilles tendon moment arm. The moment arm is computed from data collected using two reliable measurement instruments: ultrasound and video-based motion capture. Ultrasound is used to measure the perpendicular distance from the surface of the skin to the midline of the tendon. Motion capture is used to determine the perpendicular distance from the bottom of the probe to the ankle joint center. The difference between these two measures is the Achilles tendon moment arm. Unlike other methods, which require an angular change in joint position to approximate the moment arm, the hybrid method can be used to compute the moment arm directly at a specific joint angle. As a result, the hybrid method involves fewer error-prone measurements and the moment arm can be computed at the limits of the joint range of motion. The method is easy to implement and uses modalities that are less costly and more accessible than MRI. Preliminary testing using a lamb shank as a surrogate for a human ankle revealed good accuracy (3.3% error). We believe the hybrid method outlined here can be used to measure subject-specific moment arms in vivo and thus will potentially benefit research projects investigating ankle mechanics.

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