scholarly journals Semi-automatic measurements of foot morphological parameters from 3D plantar foot scans

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Giulia Rogati ◽  
Alberto Leardini ◽  
Maurizio Ortolani ◽  
Paolo Caravaggi
Keyword(s):  
Volume Index ◽  
Patient Specific ◽  
Index Test ◽  
Anatomical Landmarks ◽  
Morphological Parameters ◽  
Strong Correlations ◽  
Arch Height ◽  
Scanning Device ◽  
Foot Length ◽  
Arch Index

Abstract Background Foot healthcare research is focusing increasingly on personalized orthotic and prosthetic devices to address patient-specific morphology and ailments. Customization requires advanced 3D image processing tools to assess foot and leg geometrical parameters and alterations. The aim of this study is to present a new software for the measurement of the foot shape from 3D scans of the foot plantar surface. Methods A Kinect-based scanning device was used to acquire the 3D foot shape of 44 healthy subjects. A software was developed in Matlab to measure the foot main morphological parameters from foot scans. Principal Component Analysis was used to orientate the foot scans with respect to the same reference system. Accuracy, via percentage errors and Bland-Altman plots, and correlation of the software-based foot parameters were assessed against manual measurements. A normalized Arch Volume Index (nAVI) was proposed and correlated to the traditional Arch Index. Test-retest Intraclass Correlation Coefficient was used to assess the inter-session repeatability of foot measurements. Results The average percentage error between software and manual measurements was 1.2 ± 0.8% for foot length, 9.1 ± 3.7% for foot width, 22.3 ± 13.5% for arch height and 23.1 ± 12.7% for arch depth. Very strong correlations were observed for foot length (R = 0.97) and foot width (R = 0.83), and strong correlations for arch height (R = 0.62) and arch depth (R = 0.74). nAVI was negatively correlated to the Arch Index (R = -0.54). A small difference was found between software and manual measurements of foot length (Δ = 0.92 mm), a software overestimation of foot width (Δ = 8.6 mm) and underestimation of arch height (Δ = -1.4%) and arch depth (Δ = -11%). Moderate to excellent repeatability was observed for all measurements (0.67–0.99). Conclusions The present software appears capable to estimate the foot main morphological parameters without the need for skin markers or for identification of anatomical landmarks. Moreover, measurements are not affected by the foot orientation on the scanning device. The good accuracy and repeatability of measurements make the software a potentially useful operator-independent tool for the assessment of foot morphological alterations and for orthotics customization. nAVI may be used for a more realistic classification of foot types when 3D foot images are available.

scholarly journals Foot Arch Characterization

2010 ◽  
Vol 100 (1) ◽  
pp. 14-24 ◽  
Author(s):  
Shuping Xiong ◽  
Ravindra S. Goonetilleke ◽  
Channa P. Witana ◽  
Thilina W. Weerasinghe ◽  
Emily Yim Lee Au
Keyword(s):  
Peak Pressure ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Arch Height ◽  
Ongoing Debate ◽  
Foot Length ◽  
Foot Arch ◽  
Arch Index ◽  
The Right ◽  
Peak Pressures

Background: The medial longitudinal arch of the foot is important because it helps protect the foot from injury. Researchers have developed many measures to quantify the characteristics of the arch, and there is ongoing debate about the suitability of these different metrics. This article compares the various measures related to the foot arch, including a new metric, the midfoot dorsal angle, and then investigates the differences in the dimensional measures among various foot types. Methods: The right feet of 48 healthy individuals (24 men and 24 women) were measured, and various metrics, including the arch height index, the navicular height to arch length ratio, the arch index, the footprint index, the subjective ranking, the modified arch index, the malleolar valgus index, and the midfoot dorsal angle, were determined. Results: Correlation analyses showed that the arch index obtained from the inked footprint has a moderate to high correlation (Pearson correlation coefficients >0.50) with all measured foot-type metrics except for the malleolar valgus index. There were no differences in participant age, stature, weight, body mass index, foot length, foot width, and midfoot height among high, normal, and low foot arches. However, the high-arched group had significantly shorter arch lengths but larger navicular heights and higher midfoot dorsal angles compared with the low-arched group. There were differences in force distributions and peak pressures as well. The rearfoot had more loading and greater peak pressure whereas the midfoot had less load in the high-arched group compared with the low-arched group. Conclusions: The midfoot dorsal angle may be an appropriate metric for characterizing the foot arch because it is quick and easy to measure, without the tedious procedures associated with area calculations and dimension measurements. (J Am Podiatr Med Assoc 100(1): 14–24, 2010)

scholarly journals The Effect of Added Weight on Foot Anthropometry in Pregnant Women and Nulligravida Women

2019 ◽  
Author(s):  
Kathryn D Harrison ◽  
Krystal Thomas ◽  
Corrie Mancinelli ◽  
Petronela Meszaros ◽  
Jean L McCrory
Keyword(s):  
Pregnant Women ◽  
Post Partum ◽  
Arch Height ◽  
Third Trimester ◽  
Foot Length ◽  
Length Width ◽  
Rigidity Index ◽  
Arch Index ◽  
Index Weight ◽  
Pregnancy Weight

Abstract Background Foot anthropometry is altered by pregnancy. It is unknown if these changes are due to increased bodyweight and/or hormonal concentrations. The purpose of our study was to examine the effect of added weight on foot anthropometry in pregnancy. Methods Fifteen primigravid women and 13 nulliparous controls participated. Controls were matched to pregnant women based on self-reported pre-pregnancy weight. After informed consent, data were collected on pregnant participants in each trimester and post-partum. Foot length, width, arch index, arch height index, arch rigidity index, and arch drop were assessed. Subsequently, pregnant participants in their first two trimesters donned a weighted pack such that total weight difference from pre-pregnancy weight was 124N. Foot measurements were repeated. Third trimester participants were only measured without a pack as they were at full-pregnancy weight. In post-partum, bodyweight plus pack-weight equaled third trimester weight. For control participants, bodyweight plus pack-weight equaled third trimester weight of the pregnant participant to whom they were matched. A MANOVA was performed with the independent variables of trimester, weight condition, and leg. Tukey post-hoc analyses were performed when appropriate (α=0.05). Results Arch drop increased by 18% (p=0.007) and arch rigidity index decreased by 1% (p=0.001) while weighted across both pregnant and control groups. Increase in foot length and width and decrease in arch height index with added weight was only greater in pregnant participants compared to the control participants (p<0.05). Conclusions Adding weight produced changes in arch drop and arch rigidity index. Weight plus pregnancy was related to further alterations in anthropometry. Increased pregnancy hormone concentrations likely affect foot anthropometry in primigravid women.

scholarly journals Calcaneus height is a key morphological factor of sprint performance in sprinters

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tadashi Suga ◽  
Msafumi Terada ◽  
Takahiro Tanaka ◽  
Yuto Miyake ◽  
Hiromasa Ueno ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Body Height ◽  
Sprint Performance ◽  
Relative Height ◽  
Arch Height ◽  
Resonance Imaging ◽  
Foot Length ◽  
Foot Arch ◽  
Foot Morphology

Abstract This study examined the relationships between the foot bone morphologies and sprint performance in sprinters. Foot images in 56 male sprinters obtained using magnetic resonance imaging. The relative lengths of the forefoot bones of the big and second toes, which were calculated as total lengths of the forefoot bones for each toe normalized to the foot length, correlated significantly with personal best 100-m sprint time (r =  − 0.293 and − 0.459, both Ps < 0.05). The relative lengths of the rearfoot talus and calcaneus normalized to the foot length also correlated significantly with the sprint performance (r =  − 0.378 and − 0.496, both Ps < 0.05). Furthermore, the relative height of the calcaneus, but not the talus, normalized to body height correlated significantly with sprint performance (r =  − 0.690, P < 0.001). Additionally, the relative calcaneus height correlated significantly with the foot arch height index (r = 0.420, P = 0.001), and the foot arch height index correlated significantly with sprint performance (r =  − 0.517, P < 0.001). These findings suggest that the taller calcaneus may be a key morphological factor for achieving superior sprint performance, potentially via modeling the longer forefoot and rearfoot bones and functional foot morphology in sprinters.

Reliability of a New Method to Determine Foot Arch Height for Clinicians

2019 ◽  
Vol 109 (3) ◽  
pp. 187-192
Author(s):  
James A. Charles ◽  
Clare Mignot ◽  
Herbert F. Jelinek
Keyword(s):  
Gold Standard ◽  
Routine Clinical Practice ◽  
Arch Height ◽  
Linear Modeling ◽  
Important Indicator ◽  
Non Invasive ◽  
Foot Arch ◽  
Arch Index ◽  
Post Hoc ◽  
Processing Steps

Background: Arch height is an important indicator of risk of foot pathology. The current non-invasive gold standard based on footprint information requires extensive pre-processing. Methods used to obtain arch height that are accurate and easier to use are required in routine clinical practice. Methods: The proposed arch index diagonals (AId) method for determining the arch index (AI) reduces the complexity of the preprocessing steps. All footprints were first prepared as required by the Cavanagh and Rodgers method for determining the AI and then compared to the proposed diagonals method. Results were classified according to the Cavanagh and Rodgers cut-off values into three groups of low, normal and high AI. ANOVA and Tukey's post hoc tests were applied to identify significant differences between AI groups. Linear modeling was applied to determine the fit of the new AId method compared to the Cavanagh and Rodgers AI. Results: One hundred and ninety-six footprints were analyzed. The ANOVA indicated significant differences between the groups for AId (F1,194=94.49, p&lt;0.0001) and the Tukey post hoc tests indicated significant differences between the pair-wise comparisons (p&lt;0.001). Linear modeling indicated that the AId ratio classified more footprints in the high arch group compared to Cavanagh and Rodgers results (R2=32%, p&lt; 0.01). Intra- and inter-rater correspondence was above 90% and confirmed that the AId results provided a better indication of arch height. Conclusions: The proposed method simplifies current processing steps to derive the arch height.

Mechanics of Hip Dysplasia Reduction in Infants With the Pavlik Harness Using Patient-Specific Geometry

2014 ◽  
Author(s):  
Victor Huayamave ◽  
Christopher Rose ◽  
Mohammed Zwawi ◽  
Eduardo Divo ◽  
Faissal Moslehy ◽  
...  
Keyword(s):  
Hip Dysplasia ◽  
Current Model ◽  
Patient Specific ◽  
Type Model ◽  
Anatomical Landmarks ◽  
Muscle Action ◽  
Pavlik Harness ◽  
Three Dimensional Model ◽  
Adductor Muscles ◽  
Passive Muscle

A physics-based computational model of neonatal Developmental Dysplasia of the Hip (DDH) following treatment with the Pavlik Harness was developed to obtain muscle force contribution in order to elucidate biomechanical factors influencing the reduction of dislocated hips. Clinical observation indicates that reduction occurs in deep sleep and involves passive muscle action. Consequently, a set of five (5) adductor muscles, namely, the Adductor Brevis, Adductor Longus, Adductor Magnus, Pectineus, and Gracilis were identified as mediators of reduction using the Pavlik Harness. A Fung-type model was used to characterize the hyperelastic stress-strain muscle response. Four grades (1–4) of dislocation as specified by the International Hip Dysplasia Institute (IHDI) were considered. A three-dimensional model of the pelvis-femur-lower limb assembly of a representative 10 week-old female was generated based on CT scans of a 6-month and 14-year old female as well as the visible human project with the aid of anthropomorphic scaling of anatomical landmarks. The muscle model was calibrated to achieve equilibrium at 90° flexion and 80° abduction. The hip was computationally dislocated according to the grade under investigation, the femur was restrained to move in an envelope consistent with Pavlik Harness restraints, and the dynamic response under passive muscle action and under the effect of gravity was resolved using the ADAMS solver in Solidworks. Results of the current model with an anteversion angle of 50° show successful reduction IHDI Grades 1–3, while IHDI Grade 4 failed to reduce with the Pavlik Harness. These results are consistent with a previous study based on a simplified anatomically-consistent synthetic model and clinical reports of very low success of the Pavlik Harness for Grade 4. However, our model indicates that it is possible to achieve reduction of Grade 4 dislocation by hyperflexion. This finding is consistent with clinical procedures that utilize hyperflexion to help achieve reduction for patients with severe levels of DDH for whom the Pavlik Harness fails.

Application of image analysis in activated sludge to evaluate correlations between settleability and features of flocs and filamentous species

2009 ◽  
Vol 59 (10) ◽  
pp. 2029-2036 ◽  
Author(s):  
A. Arelli ◽  
L. Luccarini ◽  
P. Madoni
Keyword(s):  
Image Analysis ◽  
Activated Sludge ◽  
Nutrient Deficiency ◽  
Domestic Wastewater ◽  
Threshold Value ◽  
Pilot Scale ◽  
Volume Index ◽  
Morphological Parameters ◽  
Treatment Processes ◽  
Sludge Properties

Digital image analysis is a useful tool to estimate some morphological parameters of flocs and filamentous species in activated sludge wastewater treatment processes. In this work we found the correlation between some morphological parameters and sludge volume index (SVI). The sludge was taken from a pilot—scale activated sludge plant, owned by ENEA, located side stream to the Trebbo di Reno (Bologna, Italy) municipal WWTP and fed by domestic wastewater. In order to use image analysis, we developed a correct method to acquire digital microbiological observations and to obtain images altogether representative of the sludge properties. We identified and assessed the parameters needed to estimate the settleability of the sludge and evaluated the morphological filamentous features. It is known that several conditions (i.e. low F/M, nutrient deficiency, low dissolved oxygen) select specific filamentous species and their excessive growth decrease floc-forming/filaments ratio, correspond to the worse settleability properties; we found a relationship between the relative abundance of filamentous species and SVI. We also evaluated the fractal dimension parameter (FD) and determined a threshold value useful to distinguish between the “weak” and “firm” floc and we found a correlation between FD and SVI.

Effect of Running Shoe Type on the Distribution and Magnitude of Plantar Pressures in Individuals with Low- or High-Arched Feet

2009 ◽  
Vol 99 (4) ◽  
pp. 330-338 ◽  
Author(s):  
Joseph M. Molloy ◽  
Douglas S. Christie ◽  
Deydre S. Teyhen ◽  
Nancy S. Yeykal ◽  
Bradley S. Tragord ◽  
...  
Keyword(s):  
Motion Control ◽  
Negative Correlation ◽  
Contact Area ◽  
Plantar Pressure ◽  
Arch Height ◽  
Plantar Pressures ◽  
Pressure Distributions ◽  
Test Conditions ◽  
Running Shoes ◽  
Arch Index

Background: Research addressing the effect of running shoe type on the low- or high-arched foot during gait is limited. We sought 1) to analyze mean plantar pressure and mean contact area differences between low- and high-arched feet across three test conditions, 2) to determine which regions of the foot (rearfoot, midfoot, and forefoot) contributed to potential differences in mean plantar pressure and mean contact area, and 3) to determine the association between the static arch height index and the dynamic modified arch index. Methods: Plantar pressure distributions for 75 participants (40 low arched and 35 high arched) were analyzed across three conditions (nonshod, motion control running shoes, and cushioning running shoes) during treadmill walking. Results: In the motion control and cushioning shoe conditions, mean plantar contact area increased in the midfoot (28% for low arched and 68% for high arched), whereas mean plantar pressure decreased by approximately 30% relative to the nonshod condition. There was moderate to good negative correlation between the arch height index and the modified arch index. Conclusions: Cushioning and motion control running shoes tend to increase midfoot mean plantar contact area while decreasing mean plantar pressure across the low- or high-arched foot. (J Am Podiatr Med Assoc 99(4): 330–338, 2009)

Magnetic resonance imaging techniques for visualization of the subthalamic nucleus

2011 ◽  
Vol 115 (5) ◽  
pp. 971-984 ◽  
Author(s):  
Ellen J. L. Brunenberg ◽  
Bram Platel ◽  
Paul A. M. Hofman ◽  
Bart M. ter Haar Romeny ◽  
Veerle Visser-Vandewalle
Keyword(s):  
Deep Brain Stimulation ◽  
Mr Imaging ◽  
Subthalamic Nucleus ◽  
Brain Stimulation ◽  
Imaging Techniques ◽  
Patient Specific ◽  
Anatomical Landmarks ◽  
Indirect Methods ◽  
Direct Targeting ◽  
Deep Brain

The authors reviewed 70 publications on MR imaging–based targeting techniques for identifying the subthalamic nucleus (STN) for deep brain stimulation in patients with Parkinson disease. Of these 70 publications, 33 presented quantitatively validated results. There is still no consensus on which targeting technique to use for surgery planning; methods vary greatly between centers. Some groups apply indirect methods involving anatomical landmarks, or atlases incorporating anatomical or functional data. Others perform direct visualization on MR imaging, using T2-weighted spin echo or inversion recovery protocols. The combined studies do not offer a straightforward conclusion on the best targeting protocol. Indirect methods are not patient specific, leading to varying results between cases. On the other hand, direct targeting on MR imaging suffers from lack of contrast within the subthalamic region, resulting in a poor delineation of the STN. These deficiencies result in a need for intraoperative adaptation of the original target based on test stimulation with or without microelectrode recording. It is expected that future advances in MR imaging technology will lead to improvements in direct targeting. The use of new MR imaging modalities such as diffusion MR imaging might even lead to the specific identification of the different functional parts of the STN, such as the dorsolateral sensorimotor part, the target for deep brain stimulation.

Use of Plantar Contact Area to Predict Medial Longitudinal Arch Height During Walking

2006 ◽  
Vol 96 (6) ◽  
pp. 489-494 ◽  
Author(s):  
Thomas G. McPoil ◽  
Mark W. Cornwall
Keyword(s):  
Contact Area ◽  
Sensor Data ◽  
Medial Longitudinal Arch ◽  
Arch Height ◽  
Plantar Surface ◽  
Longitudinal Arch ◽  
Surface Contact ◽  
Surface Contact Area ◽  
Arch Index ◽  
Vertical Height

A study was conducted to determine whether plantar surface contact area measures calculated from footprints collected during walking can be used to predict the height of the medial longitudinal arch. Thirty healthy women participated in the study. Arch height was determined by the distance from the navicular tuberosity to the floor and by the “bony” arch index. Dynamic plantar surface contact area was recorded using a pressure platform as the subjects walked across a 12-m walkway. The arch index and the total plantar surface contact area were determined from the pressure sensor data. The results indicated that plantar surface contact area could be used to estimate only approximately 27% of the height of the medial longitudinal arch as determined by navicular tuberosity height and the bony arch index. These findings demonstrate the inability of the clinician to predict the vertical height of the medial longitudinal arch on the basis of the amount of foot plantar surface area in contact with the ground during walking. (J Am Podiatr Med Assoc 96(6): 489-494, 2006)

scholarly journals In vivo Visualization of Pig Vagus Nerve “Vagotopy” Using Ultrasound

2021 ◽  
Vol 15 ◽  
Author(s):  
Megan L. Settell ◽  
Aaron C. Skubal ◽  
Rex C. H. Chen ◽  
Maïsha Kasole ◽  
Bruce E. Knudsen ◽  
...  
Keyword(s):  
Side Effects ◽  
Vagus Nerve ◽  
Surgical Procedure ◽  
Functional Organization ◽  
Electrode Placement ◽  
Patient Specific ◽  
Therapeutic Effects ◽  
Ultrasound Images ◽  
Anatomical Landmarks ◽  
Nodose Ganglia

Background: Placement of the clinical vagus nerve stimulating cuff is a standard surgical procedure based on anatomical landmarks, with limited patient specificity in terms of fascicular organization or vagal anatomy. As such, the therapeutic effects are generally limited by unwanted side effects of neck muscle contractions, demonstrated by previous studies to result from stimulation of (1) motor fibers near the cuff in the superior laryngeal and (2) motor fibers within the cuff projecting to the recurrent laryngeal.Objective: Conventional non-invasive ultrasound, where the transducer is placed on the surface of the skin, has been previously used to visualize the vagus with respect to other landmarks such as the carotid and internal jugular vein. However, it lacks sufficient resolution to provide details about the vagus fascicular organization, or detail about smaller neural structures such as the recurrent and superior laryngeal branch responsible for therapy limiting side effects. Here, we characterize the use of ultrasound with the transducer placed in the surgical pocket to improve resolution without adding significant additional risk to the surgical procedure in the pig model.Methods: Ultrasound images were obtained from a point of known functional organization at the nodose ganglia to the point of placement of stimulating electrodes within the surgical window. Naïve volunteers with minimal training were then asked to use these ultrasound videos to trace afferent groupings of fascicles from the nodose to their location within the surgical window where a stimulating cuff would normally be placed. Volunteers were asked to select a location for epineural electrode placement away from the fascicles containing efferent motor nerves responsible for therapy limiting side effects. 2-D and 3-D reconstructions of the ultrasound were directly compared to post-mortem histology in the same animals.Results: High-resolution ultrasound from the surgical pocket enabled 2-D and 3-D reconstruction of the cervical vagus and surrounding structures that accurately depicted the functional vagotopy of the pig vagus nerve as confirmed via histology. Although resolution was not sufficient to match specific fascicles between ultrasound and histology 1 to 1, it was sufficient to trace fascicle groupings from a point of known functional organization at the nodose ganglia to their locations within the surgical window at stimulating electrode placement. Naïve volunteers were able place an electrode proximal to the sensory afferent grouping of fascicles and away from the motor nerve efferent grouping of fascicles in each subject (n = 3).Conclusion: The surgical pocket itself provides a unique opportunity to obtain higher resolution ultrasound images of neural targets responsible for intended therapeutic effect and limiting off-target effects. We demonstrate the increase in resolution is sufficient to aid patient-specific electrode placement to optimize outcomes. This simple technique could be easily adopted for multiple neuromodulation targets to better understand how patient specific anatomy impacts functional outcomes.

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