Three-Dimensional In Vivo Kinematics of the Subtalar Joint During Dorsi-Plantarflexion and Inversion–Eversion

2009 ◽  
Vol 30 (5) ◽  
pp. 432-438 ◽  
Author(s):  
Akira Goto ◽  
Hisao Moritomo ◽  
Tomonobu Itohara ◽  
Tetsu Watanabe ◽  
Kazuomi Sugamoto
Keyword(s):  
Subtalar Joint ◽  
Three Dimensional ◽  
Spatial Relationship ◽  
Neutral Position ◽  
Healthy Female ◽  
Close Spatial Relationship ◽  
Mri Sequences ◽  
Magnetic Resonance Imaging Mri ◽  
Motion Plane

Background: It is difficult to determine the kinematics of the subtalar joint because of its anatomical and functional complexity. The purpose of the study was to clarify the 3D kinematics of the subtalar joint in vivo. Materials and Methods: Subjects were four healthy female volunteers. Magnetic resonance imaging (MRI) sequences were acquired in seven positions during dorsi-plantarflexion (DPF) and in 10 positions during inversion-eversion (IE) at intervals of 10 degrees. MRI data of the talus and calcaneus in the neutral position were superimposed on images of the other positions using voxel-based registration, and relative motions and axes of rotation were visualized and quantitatively calculated. Results: The calcaneus always rotated from dorsolateral to medioplantar during DPF and IE, and the motion plane was very similar to that of the entire foot in IE. The axes of rotation of the calcaneus relative to the talus during DPF and IE had a very close spatial relationship, running obliquely from antero-dorsomedial to postero-planto-lateral and penetrating the talar neck. The rotation angle around each of these calcaneal axes tended to be greater in IE (20 degrees ± 2 degrees) than in DPF (16 degrees ± 3 degrees). In DPF, motion of the calcaneus relative to the talus occurred predominantly around maximum dorsiflexion and plantarflexion, with little movement observed at intermediate positions. During IE, the calcaneus exhibited uninterrupted motion related to foot movement. Conclusion: The subtalar joint is essentially a uniaxial joint with a motion plane almost identical to that of IE of the entire foot. Clinical Relevance: Knowledge of normal subtalar kinematics may be helpful when evaluating pathologic conditions.

Three-Dimensional In Vivo Kinematics of the Subtalar Joint During Dorsi-Plantarflexion and Inversion-Eversion

2009 ◽  
Vol 30 (05) ◽  
pp. 432-438 ◽  
Author(s):  
Akira Goto ◽  
Hisao Moritomo ◽  
Tomonobu Itohara ◽  
Tetsu Watanabe ◽  
Kazuomi Sugamoto
Keyword(s):  
Subtalar Joint ◽  
Three Dimensional ◽  
In Vivo Kinematics ◽  
And Inversion

Kinematics of the Ankle/Foot Complex: Plantarflexion and Dorsiflexion

Foot & Ankle ◽  
1989 ◽  
Vol 9 (4) ◽  
pp. 194-200 ◽  
Author(s):  
Arne Lundberg ◽  
Ian Goldie ◽  
Bo Kalin ◽  
Göran Selvik
Keyword(s):  
Plantar Flexion ◽  
Three Dimensional ◽  
Substantial Contribution ◽  
Neutral Position ◽  
Transverse Axis ◽  
Talocrural Joint ◽  
Foot Kinematics ◽  
Talocalcaneal Joint ◽  
Axis Rotation

In an in vivo investigation of eight healthy volunteers, three dimensional ankle/foot kinematics were analyzed by roentgen stereophotogrammetry in 10° steps of motion from 30° of plantar flexion to 30° of dorsiflexion of the foot. The study included all of the joints between the tibia and the first metatarsal, as well as the talocalcaneal joint, and was performed under full body load. Although the talocrural joint was found to account for most of the rotation around the transverse axis occurring from 30° of plantar flexion to 30° of dorsiflexion, there was a substantial contribution from the joints of the arch. This was seen particularly in the input arc from 30° of plantar flexion to the neutral position, where the dorsiflexion motion of these joints amounted to 10% to 41% of the total transverse axis rotation.

Rear Foot Inversion/Eversion During Gait Relative to the Subtalar Joint Neutral Position

1996 ◽  
Vol 17 (7) ◽  
pp. 406-412 ◽  
Author(s):  
Michael Raymond Pierrynowski ◽  
Steve Barry Smith
Keyword(s):  
Subtalar Joint ◽  
Three Dimensional ◽  
Neutral Position ◽  
Foot Care ◽  
Worst Case ◽  
Foot Motion ◽  
Rear Part ◽  
Valid Estimate ◽  
Foot Position ◽  
Foot Orthotic

Clinicians often fabricate foot orthotic devices at the subtalar joint neutral position (STNP) to mimic the position of the rear foot during midstance. However, rear foot motion during gait, relative to the resting standing foot position, not the STNP, is often reported in the literature. The motion of the rear foot relative to a valid estimate of the STNP is unknown. In this study, six experienced foot care specialists manually placed the rear part of the feet of nine subjects at the STNP seven or eight times to obtain a valid estimate of each subject's STNP. The worst-case mean and 95% confidence interval of the STNP estimate for any one subject was 0.0° ± 0.7°. These nine subjects then walked on a motor-driven treadmill, set at 0.89 meters/sec, and three-dimensional estimates of each subject's rear foot inversion/eversion motion were obtained, then averaged over 6 to 26 strides. For most subjects, the rear foot was always everted during stance with mean and standard deviation maximal eversion (7.2° ± 1.2°) occurring at 44% of the total gait cycle. The inversion/eversion orientation during swing was characterized by 1 ° to 2° of eversion, with a small amount of inversion in early swing. These findings have implications for the fabrication of foot orthoses, since the rear foot is rarely near the STNP during stance.

Three-dimensional spiral CT angiography in the detection of cerebral aneurysm

1998 ◽  
Vol 39 (3) ◽  
pp. 233-238 ◽  
Author(s):  
M. Strayle-Batra ◽  
M. Skalej ◽  
A. K. Wakhloo ◽  
U. Ernemann ◽  
R. Klier ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Ct Angiography ◽  
Internal Carotid ◽  
Three Dimensional ◽  
Spatial Relationship ◽  
Spiral Ct ◽  
Posterior Communicating Artery ◽  
Close Spatial Relationship ◽  
Spiral Ct Angiography ◽  
Acute Subarachnoid Hemorrhage

Purpose: The value of CT angiography in the detection and evaluation of aneurysms was compared to digital subtraction angiography (DSA) Material and Methods: Seventeen patients with acute subarachnoid hemorrhage (SAH) or with known or suspected aneurysm were investigated by means of spiral CT angiography, which included 3D reconstruction. These findings were compared with those at DSA Results: In 16 patients, 20 aneurysms were found; the remaining patient had an ectatic vessel that simulated an aneurysm. Seventeen of the angiographically proved aneurysms were detected at CT angiography (sensitivity 85%). One further aneurysm was identified retrospectively as the result of greater experience in the method. All the aneurysms that escaped detection at CT were 3 mm in size. All the vessels of the circle of Willis, except for the posterior communicating artery, were properly evaluated at CT angiography. Difficulties were encountered in assessing the posterior communicating artery and the extradural segment of the internal carotid artery owing to their close spatial relationship to the bony structures of the skull base and the cavernous sinus Conclusion: CT angiography is a low-risk technique with a low level of invasiveness that is useful in following up known aneurysms. The 3D reconstruction yields further topographic information that helps in the planning of endovascular or surgical intervention. The facility for rotating the reconstructed vessels and displaying them from different angles is of particular value in cases difficult to assess at angiography

MRI Quantification of the Impact of Ankle Position on Syndesmosis Anatomy

2016 ◽  
Vol 38 (2) ◽  
pp. 215-219 ◽  
Author(s):  
Marie-Lyne Nault ◽  
Melissa Marien ◽  
Jonah Hébert-Davies ◽  
G. Yves Laflamme ◽  
Vincent Pelsser ◽  
...  
Keyword(s):  
Measurement System ◽  
External Rotation ◽  
Neutral Position ◽  
Level Of Evidence ◽  
Ankle Motion ◽  
Radiologic Study ◽  
Ankle Trauma ◽  
Magnetic Resonance Imaging Mri ◽  
The Impact

Background: Despite the common occurrence of syndesmotic injuries in ankle trauma, the distal tibiofibular relationship remains poorly understood. The aim of this study was to evaluate the anatomical impact of ankle sagittal positioning on the tibiofibular relationship in intact ankles by using a validated magnetic resonance imaging (MRI)–based measurement system. Methods: In this radiologic study, 34 healthy volunteers underwent a series of ankle MRIs with the ankle stabilized in 3 positions: neutral position (NP), dorsiflexion (DF), and plantarflexion (PF). Using a previously validated measurement system, 6 fixed translational measurements and 2 fixed angles were recorded on each MRI and compared using paired t tests. Results: When comparing PF to DF, the anterior distance between the tibial incisura and the fibula varied from 2.5 mm to 3.9 mm ( P < .001), respectively. The middle distance between the tibial incisura and the fibula varied from 1.5 mm to 2.6 mm ( P < .001). Fibular angle varied from 8.7 degrees to 7.8 degrees of internal rotation ( P = .046), respectively. When comparing NP to DF, only the anterior distance was found to be significantly different, varying 0.4 mm ( P < .002). Conclusions: Ankle dorsiflexion leads to an increase in external rotation and lateral translation of the fibula. These changes could be measured on MRI using a validated measurement system. Ankle motion did have an impact on the distal tibiofibular relationship and should be considered in studies pertaining to syndesmosis imaging. Clinical Relevance: This is the first in vivo study demonstrating the impact of sagittal ankle position on the distal tibiofibular relationship in an uninjured ankle. Our findings also support the practice of placing the ankle in dorsiflexion when fixing a disrupted syndesmosis. Level of Evidence: Level III, comparative study.

scholarly journals In Vivo Kinematics of the Tibiotalar and Subtalar Joints in Asymptomatic Subjects: A High-Speed Dual Fluoroscopy Study

2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Koren E. Roach ◽  
Bibo Wang ◽  
Ashley L. Kapron ◽  
Niccolo M. Fiorentino ◽  
Charles L. Saltzman ◽  
...  
Keyword(s):  
Subtalar Joint ◽  
High Speed ◽  
External Rotation ◽  
Translational Motion ◽  
Three Dimensional ◽  
Tibiotalar Joint ◽  
In Vivo Kinematics ◽  
Asymptomatic Subjects ◽  
Capture Techniques

Measurements of joint kinematics are essential to understand the pathomechanics of ankle disease and the effects of treatment. Traditional motion capture techniques do not provide measurements of independent tibiotalar and subtalar joint motion. In this study, high-speed dual fluoroscopy images of ten asymptomatic adults were acquired during treadmill walking at 0.5 m/s and 1.0 m/s and a single-leg, balanced heel-rise. Three-dimensional (3D) CT models of each bone and dual fluoroscopy images were used to quantify in vivo kinematics for the tibiotalar and subtalar joints. Dynamic tibiotalar and subtalar mean joint angles often exhibited opposing trends during captured stance. During both speeds of walking, the tibiotalar joint had significantly greater dorsi/plantarflexion (D/P) angular ROM than the subtalar joint while the subtalar joint demonstrated greater inversion/eversion (In/Ev) and internal/external rotation (IR/ER) than the tibiotalar joint. During balanced heel-rise, only D/P and In/Ev were significantly different between the tibiotalar and subtalar joints. Translational ROM in the anterior/posterior (AP) direction was significantly greater in the subtalar than the tibiotalar joint during walking at 0.5 m/s. Overall, our results support the long-held belief that the tibiotalar joint is primarily responsible for D/P, while the subtalar joint facilitates In/Ev and IR/ER. However, the subtalar joint provided considerable D/P rotation, and the tibiotalar joint rotated about all three axes, which, along with translational motion, suggests that each joint undergoes complex, 3D motion.

scholarly journals Ranges of Cervical Intervertebral Disc Deformation During an In Vivo Dynamic Flexion–Extension of the Neck

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Yan Yu ◽  
Haiqing Mao ◽  
Jing-Sheng Li ◽  
Tsung-Yuan Tsai ◽  
Liming Cheng ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Imaging System ◽  
Human Subjects ◽  
Three Dimensional ◽  
Cervical Disc ◽  
Significant Difference ◽  
Flexion Extension ◽  
Fluoroscopic Imaging ◽  
Magnetic Resonance Imaging Mri

While abnormal loading is widely believed to cause cervical spine disc diseases, in vivo cervical disc deformation during dynamic neck motion has not been well delineated. This study investigated the range of cervical disc deformation during an in vivo functional flexion–extension of the neck. Ten asymptomatic human subjects were tested using a combined dual fluoroscopic imaging system (DFIS) and magnetic resonance imaging (MRI)-based three-dimensional (3D) modeling technique. Overall disc deformation was determined using the changes of the space geometry between upper and lower endplates of each intervertebral segment (C3/4, C4/5, C5/6, and C6/7). Five points (anterior, center, posterior, left, and right) of each disc were analyzed to examine the disc deformation distributions. The data indicated that between the functional maximum flexion and extension of the neck, the anterior points of the discs experienced large changes of distraction/compression deformation and shear deformation. The higher level discs experienced higher ranges of disc deformation. No significant difference was found in deformation ranges at posterior points of all the discs. The data indicated that the range of disc deformation is disc level dependent and the anterior region experienced larger changes of deformation than the center and posterior regions, except for the C6/7 disc. The data obtained from this study could serve as baseline knowledge for the understanding of the cervical spine disc biomechanics and for investigation of the biomechanical etiology of disc diseases. These data could also provide insights for development of motion preservation surgeries for cervical spine.

scholarly journals Cochlear Model for the Evaluation of MRI Sequences and Cochlear Implant Electrode Pattern at 3T

2021 ◽  
Author(s):  
Lars Uwe Scholtz ◽  
Conrad Riemann ◽  
Hans Björn Gehl ◽  
Holger Sudhoff ◽  
Ingo Todt
Keyword(s):  
Cochlear Implant ◽  
Three Dimensional ◽  
Surgical Techniques ◽  
Perceptual Quality ◽  
Electrode Position ◽  
Slice Thickness ◽  
Cochlear Model ◽  
Mri Sequences

Abstract Introduction Cochlear implant (CI) magnets and surgical techniques (e.g., positioning) have made an impact on the relationship between CI and magnetic resonance imaging (MRI) by solving the problem of pain and artifact. Recent investigations displayed the possibility to evaluate the CI electrode position by MRI in vivo. However, further improved perceptual quality is needed to allow an improved evaluation of the electrode. Aims The aim of this study was to assess a cochlear model for the examination of CI electrode pattern and MRI sequences in vitro. Materials and Methods We investigated CI electrodes in a fluid-filled three-dimensional artificial scala tympani model combined with a fluid package in a 3T MRI scanner. Different high-resolution T2 sequences (0.6–0.2 mm voxel size) were used for the visual electrode pattern evaluation for finding an optimized sequence. Results Artificial models can be used to evaluate MRI characteristics of CI electrodes. In our scanner configuration, a 0.3 mm voxel and 0.9 mm slice thickness sequence showed the best compromise between resolution and scanning time. Conclusion and Significance MRI model-based testing can be performed in vitro to evaluate CI electrodes’ pattern and to optimize sequences. An MRI model is a tool for in vitro testing of MRI sequences and might help for future in vivo applications.

scholarly journals Effects of extraosseous talotarsal stabilization on the biomechanics of flexible flatfoot subtalar joints in children: a finite element study

2021 ◽  
Vol 8 (1) ◽  
pp. 5
Author(s):  
Xiangyu Cheng ◽  
Zhiqin Deng ◽  
Weidong Song ◽  
Jianquan Liu ◽  
Wencui Li
Keyword(s):  
Finite Element ◽  
Subtalar Joint ◽  
Joint Instability ◽  
Three Dimensional ◽  
Normal Function ◽  
Neutral Position ◽  
Flat Foot ◽  
Flexible Flatfoot ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

<p class="abstract"><strong>Background:</strong> Objective of the study was to generate an experimental foundation for the clinical application of extraosseous talotarsal stabilization (EOTTS) in treatment of flexible flatfeet in children by investigating the biomechanical characteristics of flexible flatfoot and the effects of EOTTS on hindfoot biomechanics.</p><p class="abstract"><strong>Methods:</strong> Three-dimensional finite element models of the foot and ankle complex were generated from computer tomography images of a volunteer’s left foot in three states: normal, flexible flatfoot, and post-EOTTS. After validation by X-ray, simulated loads were applied to the three models in a neutral position with both feet standing.</p><p class="abstract"><strong>Results:</strong> In the flexible flatfoot model, the contact stress on the subtalar joint increased and contact areas decreased, resulting in abnormal stress distribution compared to the normal model. However, following treatment of the foot with EOTTS, these parameters returned to close to normal. Subtalar joint instability leads to a flexible flat foot. Based on this study, it is proposed that EOTTS can restore the normal function of the subtalar joint in and is an effective treatment for flexible flatfoot in children. We and many clinical data studies provide evidence for sinus tarsi implants in pediatric patients. It is showed that the formation of flexible flatfoot is induced by subtalar joint instability.</p><p class="abstract"><strong>Conclusions:</strong> Because of the EOTTS provides the best biomechanical solution to subtalar joint instability, the EOTTS became an effective form for subtalar joint instability treatment.</p>

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