scholarly journals On the hindlimb biomechanics of the avian take-off leap

2021 ◽  
Author(s):  
Erik Anthony Meilak ◽  
Pauline Provini ◽  
Colin Palmer ◽  
Neil J Gostling ◽  
Markus O Heller
Keyword(s):  
Zebra Finch ◽  
Inverse Dynamics ◽  
Bird Species ◽  
Knee Extension ◽  
External Loading ◽  
Leg Length ◽  
Hip Joints ◽  
Peak Knee ◽  
Reaction Forces ◽  
The Mean

Although extant land birds take to the air by leaping, generating the initial take-off velocity primarily from the hindlimbs, the detailed musculoskeletal mechanics remain largely unknown. We therefore simulated in silico the take-off leap of the zebra finch, Taeniopygia guttata, a model species of passerine, a class of bird which includes over half of all extant bird species. A 3D computational musculoskeletal model of the zebra finch hindlimb, comprising of 43 musculotendon units was developed and driven with previously published take-off ground reaction forces and kinematics. Using inverse dynamics, the external moments at the ankle, knee, and hip joints were calculated and contrasted to the cumulative muscle capability to balance these moments. Mean peak external flexion moments at the hip and ankle were 0.55 bodyweight times leg length (BWL) each whilst peak knee extension moments were about half that value (0.29 BWL). Muscles had the capacity to generate 146%, 230%, and 212 % of the mean peak external moments at the hip, knee, and ankle, respectively. Similarities in hindlimb morphology and external loading across passerine species suggest that the effective take-off strategy employed by the zebra finch may be shared across the passerine clade and therefore half of all birds.

scholarly journals The Effects of Walking Speed on Tibiofemoral Loading Estimated Via Musculoskeletal Modeling

2014 ◽  
Vol 30 (2) ◽  
pp. 197-205 ◽  
Author(s):  
Zachary F. Lerner ◽  
Derek J. Haight ◽  
Matthew S. DeMers ◽  
Wayne J. Board ◽  
Raymond C. Browning
Keyword(s):  
Walking Speed ◽  
Inverse Dynamics ◽  
Knee Extension ◽  
Musculoskeletal Model ◽  
Contact Forces ◽  
Muscle Forces ◽  
Musculoskeletal Models ◽  
Peak Knee ◽  
Muscle Moments ◽  
Vector Sum

Net muscle moments (NMMs) have been used as proxy measures of joint loading, but musculoskeletal models can estimate contact forces within joints. The purpose of this study was to use a musculoskeletal model to estimate tibiofemoral forces and to examine the relationship between NMMs and tibiofemoral forces across walking speeds. We collected kinematic, kinetic, and electromyographic data as ten adult participants walked on a dual-belt force-measuring treadmill at 0.75, 1.25, and 1.50 m/s. We scaled a musculoskeletal model to each participant and used OpenSim to calculate the NMMs and muscle forces through inverse dynamics and weighted static optimization, respectively. We determined tibiofemoral forces from the vector sum of intersegmental and muscle forces crossing the knee. Estimated tibiofemoral forces increased with walking speed. Peak earlystance compressive tibiofemoral forces increased 52% as walking speed increased from 0.75 to 1.50 m/s, whereas peak knee extension NMMs increased by 168%. During late stance, peak compressive tibiofemoral forces increased by 18% as speed increased. Although compressive loads at the knee did not increase in direct proportion to NMMs, faster walking resulted in greater compressive forces during weight acceptance and increased compressive and anterior/posterior tibiofemoral loading rates in addition to a greater abduction NMM.

scholarly journals Effect of knee extensor fatigue level and sex on bilateral jump-landing

2020 ◽  
Vol 6 (1) ◽  
pp. e000660 ◽  
Author(s):  
Byungjoo Noh ◽  
Chang Hong Youm ◽  
Myeounggon Lee ◽  
Hwayoung Park ◽  
Minji Son ◽  
...  
Keyword(s):  
Force Plate ◽  
Knee Extensor ◽  
Knee Extension ◽  
Knee Joints ◽  
Jump Landing ◽  
Severe Fatigue ◽  
Peak Knee ◽  
Reaction Forces ◽  
Study Participants ◽  
Maximal Effort

ObjectiveThe purpose of this study was to determine the effect of fatigue level and sex on the range of motions of the lower extremities and impulses during the jump-landing phase after performing bilateral fatiguing tasks.MethodsIn total, 41 healthy young adults volunteered for this study. Participants’ jump-landing trajectories were monitored using nine cameras, and ground reaction forces were measured using a force plate. Participants performed five maximal bilateral countermovement jumps as prefatiguing tasks. The fatiguing tasks consisted of maximal effort contractions of the knee extensor at 60°/s on a dynamometer until task failure, defined as the inability to reach 50% of the peak knee extension torque for three consecutive times. The post-task maximal bilateral jumps were immediately captured after the participants failed the fatiguing task. Participants were asked to perform this cycle again, performing the fatiguing contraction task until failure to reach 30% of the peak knee extension torque.Results and conclusionIt was found that the knee joint was more extended in the post-30% fatiguing task, which was due to the reduction of the flexion angle of the hip and knee joints in response to fatigue level. The impulses for both sexes were reduced at the severe fatigue level. Fatigability altered jump-landing kinematics, jump heights and impulses in response to fatigue level. The post-30% fatiguing task elicited more fatigue than the post-50% fatiguing task.

Changes in muscle activities and kinematics due to simulated leg length inequalities

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hannah Lena Siebers ◽  
Jörg Eschweiler ◽  
Filippo Migliorini ◽  
Valentin Michael Quack ◽  
Markus Tingart ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Rectus Femoris ◽  
Knee Extension ◽  
Pelvic Obliquity ◽  
Lateral Flexion ◽  
Leg Length ◽  
Joint Angles ◽  
Leg Muscles ◽  
Compensation Mechanisms ◽  
Musculoskeletal Problems

Abstract Muscle imbalances are a leading cause of musculoskeletal problems. One example are leg length inequalities (LLIs). This study aimed to analyze the effect of different (simulated) LLIs on back and leg muscles in combination with kinematic compensation mechanics. Therefore, 20 healthy volunteers were analyzed during walking with artificial LLIs (0–4 cm). The effect of different amounts of LLIs and significant differences to the reference condition without LLI were calculated of maximal joint angles, mean muscle activity, and its symmetry index. While walking, LLIs led to higher muscle activity and asymmetry of back muscles, by increased lumbar lateral flexion and pelvic obliquity. The rectus femoris showed higher values, independent of the amount of LLI, whereas the activity of the gastrocnemius on the shorter leg increased. The hip and knee flexion of the long leg increased significantly with increasing LLIs, like the knee extension and the ankle plantarflexion of the shorter leg. The described compensation mechanisms are explained by a dynamic lengthening of the short and shortening of the longer leg, which is associated with increased and asymmetrical muscle activity. Presenting this overview is important for a better understanding of the effects of LLIs to improve diagnostic and therapy in the future.

scholarly journals A Prospective Clinical and Radiological Evaluation at 5 Years After Arthroscopic Matrix-Induced Autologous Chondrocyte Implantation

2016 ◽  
Vol 45 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Jay R. Ebert ◽  
Michael Fallon ◽  
David J. Wood ◽  
Gregory C. Janes
Keyword(s):  
Autologous Chondrocyte Implantation ◽  
Knee Extension ◽  
Composite Score ◽  
Physical Component Score ◽  
Knee Extension Strength ◽  
Sf 36 ◽  
Peak Knee ◽  
Chondrocyte Implantation ◽  
Minute Walk ◽  
Autologous Chondrocyte

Background: While midterm outcomes after matrix-induced autologous chondrocyte implantation (MACI) are encouraging, the procedure permits an arthroscopic approach that may reduce the morbidity of arthrotomy and permit accelerated rehabilitation. Hypothesis: A significant improvement in clinical and radiological outcomes after arthroscopic MACI will exist through to 5 years after surgery. Study Design: Case series; Level of evidence, 4. Methods: We prospectively evaluated the first 31 patients (15 male, 16 female) who underwent MACI via arthroscopic surgery to address symptomatic tibiofemoral chondral lesions. MACI was followed by a structured rehabilitation program in all patients. Clinical scores were administered preoperatively and at 3 and 6 months as well as 1, 2, and 5 years after surgery. These included the Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm knee scale (LKS), Tegner activity scale (TAS), visual analog scale for pain, Short Form–36 Health Survey (SF-36), active knee motion, and 6-minute walk test. Isokinetic dynamometry was used to assess peak knee extension and flexion strength and limb symmetry indices (LSIs) between the operated and nonoperated limbs. High-resolution magnetic resonance imaging (MRI) was performed at 3 months and at 1, 2, and 5 years postoperatively to evaluate graft repair as well as calculate the MRI composite score. Results: There was a significant improvement ( P < .05) in all KOOS subscale scores, LKS and TAS scores, the SF-36 physical component score, pain frequency and severity, active knee flexion and extension, and 6-minute walk distance. Isokinetic knee extension strength significantly improved, and all knee extension and flexion LSIs were above 90% (apart from peak knee extension strength at 1 year). At 5 years, 93% of patients were satisfied with MACI to relieve their pain, 90% were satisfied with improving their ability to undertake daily activities, and 80% were satisfied with the improvement in participating in sport. Graft infill ( P = .033) and the MRI composite score ( P = .028) significantly improved over time, with 90% of patients demonstrating good to excellent tissue infill at 5 years. There were 2 graft failures at 5 years after surgery. Conclusion: The arthroscopically performed MACI technique demonstrated good clinical and radiological outcomes up to 5 years, with high levels of patient satisfaction.

scholarly journals Long term results after transepiphysal ACL reconstruction in children and adolescent

2018 ◽  
Vol 6 (4_suppl2) ◽  
pp. 2325967118S0001
Author(s):  
Christian Eberle ◽  
Wolfgang Schopf ◽  
Andree Ellermann
Keyword(s):  
Acl Reconstruction ◽  
Cartilage Damage ◽  
Long Term Results ◽  
Angular Deformity ◽  
Leg Length ◽  
Growth Disturbance ◽  
Children And Adolescent ◽  
The Mean

The aim of our study was to review the long term clinical and radiological (MRI) outcomes of adult patients who underwent ACL reconstruction as children or adolescent with emphasize to the features of growth disturbance, angular deformity, meniscal and cartilage damage and revision rate We retrospectively evaluated patient who underwent ACL reconstruction in our clinic with arthroscopic transepiphyseal technique using hamstrings graft in childhood or adolescence between the years 1997 and 2009. A total of 43 Patients were assessed. 25 male and 18 female. The average age at time of surgery was 13,5 years (8 - 16 y.), at time of assessement 22,4 years (18 - 30 y.) . The mean follow up was 10 years (4 - 16 years). The physical development of the patients was assessed with the Lysholm score and the Cincinnati Knee score scale, their satisfaction was recorded on the basis of the IKDC subjective knee evaluation form and the Tegner activity score . Leg deformity or leg length discrepancy was evaluated clinically by the observers. The instrumented Lachman test using KT1000 and manual Pivot shift test was performed to assess knee stability. MRI was used to detect graft integrity, cartilage and meniscal damages. No significant leg deformities or leg length discrepancy had been detected. The average Lysholm score was 91 points (83 - 100), the Cincinnati Knee Score was 90,4 (79 - 100) points on average . The mean IKDC score was 92 points (82 -100). The Tegner-Activity-Score changed from preop 6,8 (2-10) to post op 5,8 (2-9). 2 Patient underwent revision ACL reconstruction due to rerupture (3 and 9 years post op). 2 Patients underwent meniscal surgery during follow up (1 resection and one refixation). KT1000 evaluation showed 67% excellent, 21% good and in 12% bad results. The MRI scan showed 42 intact grafts and one unverifiable graft. One patient with cartilage damage up to 3° (ICRS), 3 patients with meniscal degeneration up to grade 2. Each patient showed a free range of motion Our data underlines that transepiphyseal ACL reconstruction in children and adolescent with hamstrings is a save procedure leading to good long term results without causing angular deformity or growth disturbance

Comparison of minimally invasive and non-invasive systems in lengthening total femoral prostheses

2018 ◽  
Vol 100-B (12) ◽  
pp. 1640-1646 ◽  
Author(s):  
M. R. Medellin ◽  
T. Fujiwara ◽  
R. Clark ◽  
L. M. Jeys
Keyword(s):  
Minimally Invasive ◽  
Leg Length Discrepancy ◽  
Implant Survival ◽  
Leg Length ◽  
Range Of Movement ◽  
Musculoskeletal Tumor Society ◽  
Non Invasive ◽  
Length Discrepancy ◽  
The Mean

AimsThe aim of this study was to describe, analyze, and compare the survival, functional outcome, and complications of minimally invasive (MI) and non-invasive (NI) lengthening total femoral prostheses.Patients and MethodsA total of 24 lengthening total femoral prostheses, 11 MI and 13 NI, were implanted between 1991 and 2016. The characteristics, complications, and functional results were recorded. There were ten female patients and ten male patients. Their mean age at the time of surgery was 11 years (2 to 41). The mean follow-up was 13.2 years (seven months to 29.25 years). A survival analysis was performed, and the failures were classified according to the Modified Henderson System.ResultsThe overall implant survival was 79% at five, ten, and 20 years for MI prostheses, and 84% at five years and 70% at ten years for NI prostheses. At the final follow-up, 13 prostheses did not require further surgery. The overall complication rate was 46%. The mean revision-free implant survival for MI and NI prostheses was 59 months and 49 months, respectively. There were no statistically significant differences in the overall implant survival, revision-free survival, or the distribution of complications between the two types of prosthesis. Infection rates were also comparable in the groups (9% vs 7%; p = 0.902). The rate of leg-length discrepancy was 54% in MI prostheses and 23% in NI prostheses. In those with a MI prosthesis, there was a smaller mean range of movement of the knee (0° to 62° vs 0° to 83°; p = 0.047), the flexion contracture took a longer mean time to resolve after lengthening (3.3 months vs 1.07 months; p < 0.001) and there was a lower mean Musculoskeletal Tumor Society (MSTS) score (24.7 vs 27; p = 0.295).ConclusionThe survival and complications of MI and NI lengthening total femoral prostheses are comparable. However, patients with NI prosthesis have more accurate correction of leg-length discrepancy, a better range of movement of the knee and an improved overall function.

scholarly journals Volume of the ligamentum capitis femoris in osteoarthritic hip joints of adult dogs

2003 ◽  
Vol 74 (1) ◽  
Author(s):  
J.D. Mande ◽  
P.M.F. Mbithi ◽  
S.W. Mbugua ◽  
I.B.J. Buoro ◽  
P.K. Gathumbi
Keyword(s):  
General Anaesthesia ◽  
Crucial Role ◽  
Hip Dysplasia ◽  
Inverse Correlation ◽  
Water Displacement ◽  
Hip Joints ◽  
Ligamentum Capitis Femoris ◽  
The Mean ◽  
Canine Hip Dysplasia

Ventrodorsal pelvic radiographs were made of 32 adult dogs under general anaesthesia. The hip joints were evaluated according to the severity of osteoarthritic changes graded as 0, 1, 2 or 3. The dogs were euthanased, the hip joints opened and the ligamentum capitis femoris dissected out in toto. The volume of each ligament was determined using a water displacement technique and the mean volume compared to the four radiographic grades of osteoarthritis. There was an inverse correlation (r = -0.75) between the mean volume of the ligamentum capitis femoris and the increasing severity of osteoarthritis as assessed by radiography. The results confirmed the crucial role of radiography in the clinical evaluation of hip dysplasia and osteoarthritis in the adult dog. Assessment of the volume of the ligamentum capitis femoris revealed that it is an important tool for research in canine hip dysplasia and osteoarthritis.

scholarly journals Long-term species richness-abundance dynamics in relation to species departures and arrivals in wintering urban bird assemblages

2019 ◽  
Vol 5 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Jukka Suhonen ◽  
Jukka Jokimäki
Keyword(s):  
Species Richness ◽  
Bird Species ◽  
Total Abundance ◽  
Bird Species Richness ◽  
Abundance Dynamics ◽  
Local Species Richness ◽  
Local Species ◽  
The Mean ◽  
Urban Bird ◽  
Number Of Individuals

Abstract Temporal dynamics of local assemblages depend on the species richness and the total abundance of individuals as well as local departure and arrival rates of species. We used urban bird survey data collected from the same 31 study plots and methods during three winters (1991–1992; 1999–2000 and 2009–2010) to analyze the temporal relationship between bird species richness and total number of individuals (abundance). We also evaluated local departures and arrivals of species in each assemblage. In total, 13,812 individuals of 35 species were detected. The temporal variation in bird species richness followed the variation in the total number of individuals. The numbers of local departure and arrival events were similar. Also, the mean number of individuals of the recently arrived species (8.6) was almost the same as the mean number of individuals of the departed species (8.2). Risk of species departure was inversely related to number of individuals. Local species richness increased by one species when the total abundance of individuals increased by around 125 individuals and vice versa. Our results highlight the important role of local population departures and arrivals in determining the local species richness-abundance dynamics in human-dominated landscapes. Local species richness patterns depend on the total number of individuals as well as both the departure-arrival dynamics of individual species as well as the dynamics of all the species together. Our results support the more individuals hypothesis, which suggests that individual-rich assemblages have more species.

scholarly journals Longitudinal variation in mechanical competence of bone along the avian humerus.

1995 ◽  
Vol 198 (1) ◽  
pp. 209-212
Author(s):  
R H Bonser
Keyword(s):  
Mechanical Properties ◽  
Trabecular Bone ◽  
Cortical Bone ◽  
Vickers Microhardness ◽  
Bird Species ◽  
Longitudinal Variation ◽  
The Mean ◽  
Compressive Tests

Vickers microhardness tests were used to gauge the mechanical "competence" (ability to resist bending and failure) of cortical and trabecular bone along the humeri of three bird species. Hardness was greatest at the mid-length portion of the shaft. The mean hardness of trabeculae, where present, was between 78.7 and 90.9% of that of the adjacent cortical bone. The possible causes of this are briefly discussed. Microhardness tests offer the opportunity to gauge differences in mechanical properties over small distances and might usefully be applied to test the homogeneity of mechanical properties within specimens for tensile or compressive tests.

scholarly journals Does the closed fishing season influence the ichthyofauna consumed by Larus dominicanus?

2017 ◽  
Vol 65 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Maiara Larissa Miotto ◽  
Barbara Maichak de Carvalho ◽  
Henry Louis Spach
Keyword(s):  
Bird Species ◽  
Strong Relationship ◽  
Morphometric Measurements ◽  
Fishing Activity ◽  
Trawl Fishery ◽  
Shrimp Trawl ◽  
Larus Dominicanus ◽  
The Family ◽  
The Mean ◽  
Closed Season

Abstract Fish that are incidentally caught by shrimp trawling represent a predictable and abundant resource for feeding several bird species, especially for the gull Larus dominicanus. This fishing activity is subject to disruptions throughout the year during closed fishing seasons, when other fishing modalities are exercised, which can alter the composition, abundance and size of the fish bycatch. This study evaluated the influence of the restriction of fishing period of shrimp (closed season) on the diet of L. dominicanus, on the Paraná State coast. From December 2013 to August 2014, 10 pellets were collected per month in two distinct areas that have shrimp trawl fishery as the main economic activity: one continental and another in an estuarine island. In total, 920 fish were identified, divided into four families and 15 species, especially the family Sciaenidae with 11 species. There were differences in abundance and biomass of species between areas and between seasons of pre-closure, closure and post-closure. Differences for the mean total length of the species were only detected between the pre-closed and closed seasons in one area. This study evidenced the strong relationship between L. dominicanus and the shrimp trawl fishery, the species composition identified in the pellets and their respective morphometric measurements follow the same pattern of the literature for fish discarded in trawling activities.

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