Local Bone Deformation at Two Predominant Sites for Stress Fractures of the Tibia: An In Vivo Study

1998 ◽  
Vol 19 (7) ◽  
pp. 479-484 ◽  
Author(s):  
Ingrid Ekenman ◽  
Kjartan Halvorsen ◽  
Pär Westblad ◽  
Li Fellãnder-Tsai ◽  
Christer Rolf
Keyword(s):  
Stance Phase ◽  
Distal Tibia ◽  
Force Plate ◽  
Stress Fractures ◽  
Heel Strike ◽  
Local Bone ◽  
Healthy Female ◽  
Reaction Forces

Local bone deformation was registered at two predominant injury sites for tibial stress fractures in a healthy female volunteer. Two instrumented strain gauge staples were inserted under local anesthesia to the anterior middiaphysis (AM) and to the posteromedial part of the distal tibia (PD). Calibration and reliability of the instrumented staple system have previously been demonstrated in vitro. Concomitant ground reaction forces were registered with a Kistler force plate. Studying peak values, it was shown that during a voluntary 30-cm forward jump, PD deformation was greater during forefoot landing (2700–4200 microstrain) than during a heel strike landing (1200–1900 microstrain) and also compared with the concomitant AM deformation under both above testing conditions (1300–1900 microstrain). The stance phase during walking resulted in PD deformation of 950 microstrain, whereas the concomitant AM deformation was 334 microstrain. The greatest AM deformation (mean, 2128 microstrain) was registered during ground contact after a voluntary vertical drop from a height of 45 cm, concomitant with a PD deformation of 436 microstrain. These data are the first to show different local deformations at various sites of the tibia in vivo. The PD deformation was larger than previously noted from other parts of the tibia, whereas the middiaphysis data are consistent with other reports. The results may support the clinical assumption of different etiologies for stress fractures at these predominant sites.

A Robotic Cadaveric Flatfoot Analysis of Stance Phase

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Lyle T. Jackson ◽  
Patrick M. Aubin ◽  
Matthew S. Cowley ◽  
Bruce J. Sangeorzan ◽  
William R. Ledoux
Keyword(s):  
Surgical Treatment ◽  
Degrees Of Freedom ◽  
Stance Phase ◽  
Gait Cycle ◽  
Ground Reaction Forces ◽  
Pes Planus ◽  
Reaction Forces ◽  
Vertical Ground

The symptomatic flatfoot deformity (pes planus with peri-talar subluxation) can be a debilitating condition. Cadaveric flatfoot models have been employed to study the etiology of the deformity, as well as invasive and noninvasive surgical treatment strategies, by evaluating bone positions. Prior cadaveric flatfoot simulators, however, have not leveraged industrial robotic technologies, which provide several advantages as compared with the previously developed custom fabricated devices. Utilizing a robotic device allows the researcher to experimentally evaluate the flatfoot model at many static instants in the gait cycle, compared with most studies, which model only one to a maximum of three instances. Furthermore, the cadaveric tibia can be statically positioned with more degrees of freedom and with a greater accuracy, and then a custom device typically allows. We created a six degree of freedom robotic cadaveric simulator and used it with a flatfoot model to quantify static bone positions at ten discrete instants over the stance phase of gait. In vivo tibial gait kinematics and ground reaction forces were averaged from ten flatfoot subjects. A fresh frozen cadaveric lower limb was dissected and mounted in the robotic gait simulator (RGS). Biomechanically realistic extrinsic tendon forces, tibial kinematics, and vertical ground reaction forces were applied to the limb. In vitro bone angular position of the tibia, calcaneus, talus, navicular, medial cuneiform, and first metatarsal were recorded between 0% and 90% of stance phase at discrete 10% increments using a retroreflective six-camera motion analysis system. The foot was conditioned flat through ligament attenuation and axial cyclic loading. Post-flat testing was repeated to study the pes planus deformity. Comparison was then made between the pre-flat and post-flat conditions. The RGS was able to recreate ten gait positions of the in vivo pes planus subjects in static increments. The in vitro vertical ground reaction force was within ±1 standard deviation (SD) of the in vivo data. The in vitro sagittal, coronal, and transverse plane tibial kinematics were almost entirely within ±1 SD of the in vivo data. The model showed changes consistent with the flexible flatfoot pathology including the collapse of the medial arch and abduction of the forefoot, despite unexpected hindfoot inversion. Unlike previous static flatfoot models that use simplified tibial degrees of freedom to characterize only the midpoint of the stance phase or at most three gait positions, our simulator represented the stance phase of gait with ten discrete positions and with six tibial degrees of freedom. This system has the potential to replicate foot function to permit both noninvasive and surgical treatment evaluations throughout the stance phase of gait, perhaps eliciting unknown advantages or disadvantages of these treatments at other points in the gait cycle.

scholarly journals Movement Coupling at the Ankle During the Stance Phase of Running

2000 ◽  
Vol 21 (3) ◽  
pp. 232-239 ◽  
Author(s):  
Alex Stacoff ◽  
Benno M. Nigg ◽  
Christoph Reinschmidt ◽  
Anton J. van den Bogert ◽  
Arne Lundberg ◽  
...  
Keyword(s):  
Stance Phase ◽  
Three Dimensional ◽  
Heel Strike ◽  
Second Phase ◽  
Healthy Male ◽  
Bone Level ◽  
Joint Coordinate System ◽  
Male Subjects

The purpose of this study was to quantify movement coupling at the ankle during the stance phase of running using bone-mounted markers. Intracortical bone pins with reflective marker triads were inserted under standard local anaesthesia into the calcaneus and the tibia of five healthy male subjects. The three-dimensional rotations were determined using a joint coordinate system approach. Movement coupling was observed in all test subjects and occurred in phases with considerable individual differences. Between the shoe and the calcaneus coupling increased after midstance which suggested that the test shoes provided more coupling for inversion than for eversion. Movement coupling between calcaneus and tibia was higher in the first phase (from heel strike to midstance) compared with the second phase (from midstance to take-off). This finding is in contrast to previous in-vitro studies but may be explained by the higher vertical loads of the present in-vivo study. Thus, movement coupling measured at the bone level changed throughout the stance phase of running and was found to be far more complex than a simple mitered joint or universal joint model.

Shock Absorbency of Factors in the Shoe/Heel Interaction—With Special Focus on Role of the Heel Pad

Foot & Ankle ◽  
1989 ◽  
Vol 9 (6) ◽  
pp. 294-299 ◽  
Author(s):  
Uffe Jørgensen ◽  
Finn Bojsen-Møller
Keyword(s):  
Force Plate ◽  
Heel Strike ◽  
Overuse Injuries ◽  
Special Focus ◽  
Shock Absorption ◽  
Ethyl Vinyl ◽  
Shock Absorbers ◽  
Heel Pad ◽  
Eva Foam

The heel pad acts as a shock absorber in walking and in heel-strike running. In some patients, a reduction of its shock-absorbing capacity has been connected to the development of overuse injuries. In this article, the shock absorption of the heel pad as well as external shock absorbers are studied. Individual variation and the effect of trauma and confinement on the heel pad were specifically investigated. Drop tests, imitating heel impacts, were performed on a force plate. The test specimens were cadaver heel pads (n = 10); the shoe sole component consisted of ethyl vinyl acetate (EVA) foam and Sorbothane inserts. The shock absorption was significantly greater in the heel pad than in the external shock absorbers. The mean heel pad shock absorption was 1.1 times for EVA foam and 2.1 times for Sorbothane. The shock absorption varied by as much as 100% between heel pads. Trauma caused a decrease in the heel pad shock absorbency (24%), whereas heel pad confinement increased the shock absorbency (49% in traumatized heel pads and 29.5% in nontraumatized heel pads). These findings provide a biomechanical rationale for the clinical observations of a correlation between heel pad shock absorbency loss and heel strike-dependent overuse injuries. To increase shock absorbency, confinement of the heel pad should be attempted in vivo.

A Cadaverically Evaluated Dynamic FEM Model of Closed-Chain TKR Mechanics

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Joel L. Lanovaz ◽  
Randy E. Ellis
Keyword(s):  
Model Performance ◽  
Element Model ◽  
Joint Kinematics ◽  
Contact Friction ◽  
Model Parameters ◽  
Factors Affecting ◽  
Reaction Forces ◽  
Total Knee

Knowledge of the behavior and mechanics of a total knee replacement (TKR) in an in vivo environment is key to optimizing the functional outcomes of the implant procedure. Computational modeling has shown to be an important tool for investigating biomechanical variables that are difficult to address experimentally. To assist in examining TKR mechanics, a dynamic finite-element model of a TKR is presented. The objective of the study was to develop and evaluate a model that could simulate full knee motion using a physiologically consistent quadriceps action, without prescribed joint kinematics. The model included tibiofemoral (TFJs) and patellofemoral joints (PFJs), six major ligament bundles and was driven by a uni-axial representation of a quadricep muscle. An initial parameter screening analysis was performed to assess the relative importance of 31 different model parameters. This analysis showed that ligament insertion location and initial ligament strain were significant factors affecting simulated joint kinematics and loading, with the contact friction coefficient playing a lesser role and ligament stiffness having little effect. The model was then used to simulate in vitro experiments utilizing a flexed-knee-stance testing rig. General model performance was assessed by comparing simulation results with experimentally measured kinematics and tibial reaction forces collected from two implanted specimens. The simulations were able to reproduce experimental differences observed between the test specimens and were able to accurately predict trends seen in the tibial reaction loads. The simulated kinematics of the TFJ and PFJ were less consistent when compared with experimental data but still reproduced many trends.

scholarly journals Effect of 3β, hydroxy-lup-20(29)-en-28-oic acid on 7,12-Dimethylbenz(a) anthracene impaired cellular homeostasis in extrahepatic organs of Sprague Dawley rats

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Pardeep Kaur ◽  
Rajbir Kaur ◽  
Rohit Arora ◽  
Saroj Arora
Keyword(s):  
Antioxidant Enzymes ◽  
Betulinic Acid ◽  
Detoxification Enzymes ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Healthy Female ◽  
Polycyclic Aromatic ◽  
Membrane Bound

3β, hydroxy-lup-20(29)-en-28-oic acid (Betulinic acid), a pentacyclic lupane-type triterpene has diverse pharmacological functions both in vitro and in vivo. The present study focuses its protective effect on polycyclic aromatic hydrocarbon (7,12- Dimethylbenz(a)anthracene or DMBA) induced alterations in membrane bound ATPases, detoxification enzymes and antioxidant enzymes in stomach and lungs of female Sprague Dawley rats. Healthy female Sprague Dawley rats were randomly assorted into six groups and the treatments were given orally for 7 weeks on alternate days. It was observed that betulinic acid facilitated the downregulation of elevated membrane bound ATPases (Na+/K+- ATPase, Ca2+-ATPase and Mg2+-ATPase) in DMBA administered rats. Likewise, the detoxification enzymes as well as antioxidant enzymes were modulated to normalcy in rats. Overall, betulinic acid was seen to be effective modulator of DMBA induced alterations in biochemical parameters.

Determination of Gait Events Using an Externally Mounted Shank Accelerometer

2013 ◽  
Vol 29 (1) ◽  
pp. 118-122 ◽  
Author(s):  
Jonathan Sinclair ◽  
Sarah J. Hobbs ◽  
Laurence Protheroe ◽  
Christopher J. Edmundson ◽  
Andrew Greenhalgh
Keyword(s):  
Distal Tibia ◽  
Force Platform ◽  
Biomechanical Analysis ◽  
Alternative Methods ◽  
Heel Strike ◽  
Strong Correlations ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Vertical Ground Reaction Forces

Biomechanical analysis requires the determination of specific foot contact events. This is typically achieved using force platform information; however, when force platforms are unavailable, alternative methods are necessary. A method was developed for the determination of gait events using an accelerometer mounted to the distal tibia, measuring axial accelerations. The aim of the investigation was to determine the efficacy of this method. Sixteen participants ran at 4.0 m/s ±5%. Synchronized tibial accelerations and vertical ground reaction forces were sampled at 1000 Hz as participants struck a force platform with their dominant foot. Events determined using the accelerometer, were compared with the corresponding events determined using the force platform. Mean errors of 1.68 and 5.46 ms for average and absolute errors were observed for heel strike and of –3.59 and 5.00 ms for toe-off. Mean and absolute errors of 5.18 and 11.47 ms were also found for the duration of the stance phase. Strong correlations (r= .96) were also observed between duration of stance obtained using the two different methods. The error values compare favorably to other alternative methods of predicting gait events. This suggests that shank-mounted accelerometers can be used to accurately and reliably detect gait events.

scholarly journals Loss of phosphatase and tensin homolog (PTEN) in myeloid cells controls inflammatory bone destruction by regulating the osteoclastogenic potential of myeloid cells

2013 ◽  
Vol 74 (1) ◽  
pp. 227-233 ◽  
Author(s):  
Stephan Blüml ◽  
Martin Friedrich ◽  
Tobias Lohmeyer ◽  
Emine Sahin ◽  
Victoria Saferding ◽  
...  
Keyword(s):  
Myeloid Cells ◽  
Bone Destruction ◽  
Precursor Cells ◽  
Nuclear Factor ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog ◽  
Inflammatory Conditions ◽  
Local Bone

ObjectiveLocal bone destruction in rheumatic diseases, which often leads to disability and severely reduced quality of life, is almost exclusively mediated by osteoclasts. Therefore, it is important to understand pathways regulating the generation of osteoclasts. Here, we analysed the impact of the Phosphoinositide-3-Kinase (PI3K)/Phosphatase and tensin homolog (PTEN) axis on osteoclast generation and bone biology under basal and inflammatory conditions.MethodsWe analysed osteoclastogenesis of wildtype (wt) and PTEN−/− cells in vitro and in vivo, pit resorption and qPCR of osteoclasts in vitro. Mice with a myeloid cell-specific deletion of PTEN and wt littermate mice were investigated by bone histomorphometry and clinical and histological assessment in the human tumour necrosis factor (TNF)-transgenic (hTNFtg) arthritis model.ResultsWe show that myeloid-specific PTEN−/− mice display increased osteoclastogenesis in vitro and in vivo compared to wt mice. Loss of PTEN did not affect the generation or survival of osteoclast precursor cells. However, PTEN deficiency greatly enhanced receptor activator of nuclear factor κ-B ligand (RANKL)-induced expression of the master transcription factor of osteoclastogenesis, nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), resulting in markedly increased terminal differentiation of osteoclasts in vitro. We also observed increased osteoclastogenesis under inflammatory conditions in the hTNFtg mouse model of arthritis, where hTNFtg/myeloid-specific PTEN−/− mice displayed enhanced local bone destruction as well as osteoclast formation in the inflamed joints. The extent of synovial inflammation, however, as well as recruitment of osteoclast precursor cells was not different between wt and myeloid-specific PTEN−/− mice.ConclusionsThese data demonstrate that loss of PTEN and, therefore, sustained PI3-Kinase signalling in myeloid cells especially, elevates the osteoclastogenic potential of myeloid cells, leading to enhanced inflammatory local bone destruction. Therefore, although our study allows no direct translational conclusion since we used a conditional knockout approach, the therapeutic targeting of the PI3-Kinase pathway may be of benefit in preventing structural joint damage.

Tibial bone loads during basketball maneuvers

2021 ◽  
Author(s):  
Chenxi Yan ◽  
Stuart Warden ◽  
Mariana E Kersh
Keyword(s):  
Strain Rate ◽  
Compressive Strain ◽  
Management Strategies ◽  
Distal Tibia ◽  
Stress Fractures ◽  
Basketball Players ◽  
Strain And Strain Rate ◽  
Microdamage Accumulation ◽  
Anterior Tibial

The tibia is a common site for stress fractures, which are believed to develop from microdamage accumulation to repetitive sub-yield strains. There is a need to understand how the tibia is loaded in vivo to understand how stress fractures develop and design exercises to build a more robust bone. Here, we use subject-specific, muscle-driven, finite element simulations of 11 basketball players to calculate strain and strain rate distributions at the midshaft and distal tibia during six activities: walking, sprinting, lateral cut, jumping after landing, changing direction from forward-to-backward sprinting, and changing direction while side shuffling. Maximum compressive strains were at least double maximum tensile microstrains (mu) during the stance phase of all activities. Sprinting and lateral cut had the highest compressive (-2773 +/- 934 mu and -2266 +/- 815 mu, respectively) and tensile (999 +/- 381 mu and 907 +/- 261 mu, respectively) strains. These activities also had the highest strains rates (peak compressive strain rate = 46237 +/- 38217 mu/s and 41510 +/- 17245 mu/s, respectively). Compressive strains principally occurred in the posterior tibia for all activities; however, tensile strain location varied. In particular, activities involving a change in direction increased tensile loads in the anterior tibia. These observations may guide preventative and management strategies for tibial stress fractures. In terms of prevention, the strain distributions suggest individuals should perform activities involving changes in direction during growth to adapt different parts of the tibia and develop a more fatigue resistant bone. In terms of management, the greater strain and strain rates during sprinting than jumping suggests jumping activities may be commenced earlier than full pace running. The greater anterior tensile strains during changes in direction suggest introduction of these types of activities should be delayed during recovery from an anterior tibial stress fractures, which have a high-risk of healing complications.

In Vitro Simulation of Stance Phase Gait Part I: Model Verification

2003 ◽  
Vol 24 (8) ◽  
pp. 614-622 ◽  
Author(s):  
Christof Hurschler ◽  
Judith Emmerich ◽  
Nikolaus Wülker
Keyword(s):  
Stance Phase ◽  
Reaction Force ◽  
Three Dimensional ◽  
Model Verification ◽  
Tibial Rotation ◽  
Kinetic Measurements ◽  
In Vitro Simulation ◽  
Muscle Groups

An in vitro simulator was developed to reproduce the kinematics and kinetics of stance phase gait on cadaver foot specimens. Ground reaction force was applied by a tilting angle- and force-controlled translation stage upon which a pressure measuring platform was mounted; tibial rotation was reproduced by a servomotor. Force was applied to nine tendons of the foot flexor and extensor muscle groups, and three-dimensional hind- and forefoot motion was measured. The model was verified based on in vivo kinematic and kinetic measurements. It was found to be in good general agreement with some exceptions which include a slightly more lateral gait line.

In Vivo Forces in the Plantar Fascia During the Stance Phase of Gait

2003 ◽  
Vol 93 (6) ◽  
pp. 429-442 ◽  
Author(s):  
Erin D. Ward ◽  
Kevin M. Smith ◽  
Jay R. Cocheba ◽  
Patrick E. Patterson ◽  
Robert D. Phillips
Keyword(s):  
Muscle Activity ◽  
Plantar Fasciitis ◽  
Subtalar Joint ◽  
Stance Phase ◽  
Plantar Fascia ◽  
Heel Strike ◽  
Cadaveric Specimen ◽  
Orthopedic Medicine ◽  
Loading System

Plantar fasciotomies have become commonplace in podiatric and orthopedic medicine for the treatment of plantar fasciitis. However, several complications have been associated with plantar fascial release. It has been speculated that the cause of these complications is excessive release of the plantar fascia. The aim of this project was to determine whether the amount of fascia released, from medial to lateral, causes a significant increase in force in the remaining fascia. A dynamic loading system was developed that allowed a cadaveric specimen to replicate the stance phase of gait. The system was capable of applying appropriate muscle forces to the extrinsic tendons on the foot and replicating the in vivo timing of the muscle activity while applying force to the tibia and fibula from heel strike to toe-off. As the plantar fascia was sequentially released from medial to lateral, from intact to 33% released to 66% released, the real-time force and the duration of force in the remaining fascia increased significantly, and the force was shifted later in propulsion. In addition, the subtalar joint was unable to resupinate as the amount of fascia release increased, indicating a direct relationship between the medial band of the plantar fascia and resupination of the subtalar joint during late midstance and propulsion. (J Am Podiatr Med Assoc 93(6): 429-442, 2003)

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