Biomecânica: Modelos do Pé - Foot Models

Foot Models for Clinical Gait Analysis:

• Gait & Posture 23 (2006) 399-400
"The last few years have seen the publication of a plethora of foot models. This edition of Gait and Posture contains two more. These represent models that have attracted considerable attention when presented at conferences over the last few years and are now available for us to peruse in detail."


• Comparison of three-dimensional multi-segmental foot models used in clinical gait laboratories
"This study explores differences in kinematics and repeatability between five three-dimensional multi-segmented foot models. The five models include duPont, Heidelberg, Oxford Child, Leardini, and Utah."




Australia:

• Multi-segment kinematic model of the foot–shoe complex
The reliability, accuracy and minimal detectable difference of a multi-segment kinematic model of the foot–shoe complex

"We present a kinematic model that is reliable, accurate and sensitive to describe the kinematics of the foot–shoe complex and lower leg during walking gait. In order to achieve this, a new marker set was established, consisting of 25 markers applied on the shoe and skin surface, which informed a four segment kinematic model of the foot–shoe complex and lower leg."




Germany:

• Consistency of a biomechanical foot model for clinical gait analysis
"A model of the foot, derived fromthe Heidelberg Foot Measurement Method (HFMM), was implemented in order to analyse pathological gait. The present work deals with validation and is based on a comparison between a group of healthy adults and data previously published. Furthermore, the effect of changing the position of some relevant markers was tested. It appeared that these variations can introduce misleading bias in most angles."

• Kinematic differences between normal and low arched feet in children
Kinematic differences between normal and low arched feet in children using the Heidelberg foot measurement method

"The purpose of this study was to investigate the kinematics of normal arched and low arched feet in children and use this data toquantify the differences between thetwofoot types during walking gait. Multi-segment foot motion was measured, using the Heidelberg foot measurement method (HFMM), for 25 normal arched feet and 27 low arched feet in 9–12-year-old children."


• The Heidelberg foot measurement method: Development, description and assessment
"The aim of this study was to develop and evaluate a kinematic measurement method for the foot that could be applied clinically to measure foot function including all typical foot deformities. The ankle was modelled as two anatomically based hinge joints rotating around anatomical axes estimated by the use of projection angles. For the mid- and forefoot a descriptive approach was chosen by defining angles between anatomical landmarks or reference points derived from these landmarks."




Italy:

• Characterizing multisegment foot kinematics during gait in diabetic foot patients
"The prevalence of diabetes mellitus has reached epidemic proportions, this condition may result in multiple and chronic invalidating long term complications. Among these, the diabetic foot, is determined by the simultaneous presence of both peripheral neuropathy and vasculopathy that alter the biomechanics of the foot with the formation of callosity and ulcerations. To diagnose and treat the diabetic foot is crucial to understand the foot complex kinematics. Most of gait analysis protocols represent the entire foot as a rigid body connected to the shank. Nevertheless the existing multisegment models cannot completely decipher the impairments associated with the diabetic foot."
• Modifying the Rizzoli foot model to improve the diagnosis of pes-planus - (open access)
Modifying the Rizzoli foot model to improve the diagnosis of pes-planus:
application to kinematics of feet in teenagers

"Background:
A number of multi-segment foot protocols have been proposed to obtain measurements of clinical value. In the clinical assessment of foot pathologies and deformities, such as in the pes-planus, the frontal-plane alignment of the calcaneus and the dynamic properties of the medial longitudinal arch are critical parameters though often neglected by the majority of foot protocols. The aim of the present work is to modify an established foot protocol to obtain static and kinematic measures more consistent with corresponding clinical observations. Moreover, while many papers have reported kinematic data from varying populations, few investigations have focussed on young participants from same-age cohorts."


• Repeatability of a multi-segment foot protocol in adult subjects
"Despite the numerous protocols for multi-segment kinematic analysis of the foot, the literature is scarce regarding relevant measures of reliability. The aim of the present workwas to assess the inter-trial, intersession and inter-examiner variability of one of these protocols by an established method. The kinematics of the joints of the foot of two volunteers were analyzed by four examiners with different degrees of experience in three sessions, two-to-four weeks apart."

• Repeatability of a 3D multi-segment foot model protocol in presence of foot deformities
"Repeatability studies on 3D multi-segment foot models (3DMFMs) have mainly considered healthy participants which contrasts with the widespread application of these models to evaluate foot pathologies. The current study aimed at establishing the repeatability of the 3DMFM described by Leardini et al. in presence of foot deformities."

• Repeatability of stance phase kinematics from a multi-segment foot model in people aged 50 years
Repeatability of stance phase kinematics from a multi-segment foot model
in people aged 50 years and older

"Confidence in 3D multi-segment foot models has been limited by a lack of repeatability data, particularly in older populations that may display unique functional foot characteristics. This study aimed to determine the intra and inter-observer repeatability of stance phase kinematic data from a multi-segment foot model described by Leardini et al. in people aged 50 years or older. Twenty healthy adults participated (mean age 65.4 years SD 8.4)."




Korea:

• Repeatability of a Multi-segment Foot Model with a 15-Marker Set in Normal Children
"The use of three-dimensional multi-segment foot models (3D MFMs) is increasing since they have superior ability to illustrate the effect of foot and ankle pathologies on intersegmental motion of the foot compared to single-segment foot model gait analysis. However, validation of the repeatability of the 3D MFMs is important for their clinical use. Although many MFMs have been validated in normal adults, research on MFM repeatability in children is lacking. The purpose of this study is to validate the intrasession, intersession, and interrater repeatability of an MFM with a 15-marker set (DuPont foot model) in healthy children."




UK:

• Movement of the human foot in 100 pain free individuals
Movement of the human foot in 100 pain free individuals aged 18–45:
implications for understanding normal foot function

"Foot deformity is a common occurrence in cerebral palsy (CP), affecting around 90% of the population. The hallux is often implicated, with valgus or adduction deformity occurring most frequently. In addition, dynamic function of the hallux during gait is often compromised. However, the relationship between motion of the hallux and the rest of the foot is unknown. The aim of this study is to investigate this relationship, and thereby improve understanding of the role of the hallux during gait in children with CP."


Oxford foot model (OFM):

• Analysis of a kinetic multi-segment foot model. Part I
Analysis of a kinetic multi-segment foot model.
Part I: Model repeatability and kinematic validity

"Kinematic multi-segment foot models are still evolving, but have seen increased use in clinical and research settings. The addition of kinetics may increase knowledge of foot and ankle function as well as influence multi-segment foot model evolution; however, previous kinetic models are too complex for clinical use. In this study we present a three-segment kinetic foot model and thorough evaluation of model performance during normal gait. In this first of two companion papers, model reference frames and joint centers are analyzed for repeatability, joint translations are measured, segment rigidity characterized, and sample joint angles presented."


• Analysis of a kinetic multi-segment foot model. Part II
Analysis of a kinetic multi-segment foot model
Part II: Kinetics and clinical implications

"In this second of two companion papers, we complete the presentation and analysis of a three segment kinetic foot model by incorporating kinetic parameters and calculating joint moments and powers. The model was tested on 17 pediatric subjects (ages 7–18 years) during normal gait."


• A comparison of foot kinematics in people with normal and flat-arched feet
A comparison of foot kinematics in people with normal- and flat-arched feet using the
Oxford Foot Model

"Foot posture is thought to influence predisposition to overuse injuries of the lower limb. Although the mechanisms underlying this proposed relationship are unclear, it is thought that altered foot kinematics may play a role. Therefore, this study was designed to investigate differences in foot motion between people with normal- and flat-arched feet using the Oxford Foot Model (OFM)."


• Correlation between plantar pressure and Oxford Foot Model kinematics in clubfoot
"Plantar pressure does not always correlate to foot position. In post surgical clubfoot the hindfoot position directly correlates with hindfoot loading and the forefoot position inversely correlates with hindfoot loading."

• Intra-rater repeatability of the Oxford foot model in healthy children
Intra-rater repeatability of the Oxford foot model in healthy children in different stages of the foot roll over process during gait

"The repeatability of the Oxford foot model has been reported, but possible variations in the repeatability during the foot roll over process have not been examined. The aim of this study was to determine the relative and absolute repeatability of the model for each stage of the foot roll over process during gait and to compare foot kinematic data from this study with that from another centre as a preliminary examination of the model's inter-centre repeatability and validity."


• Marker cluster rigidity in a multi-segment foot model
"Multi-segment foot models (MSFM) are used in gait analysis for the diagnosis and planning of treatment for patients with foot deformities. Like other biomechanical models, MSFMs represent the leg and foot as a series of linked rigid segments, but such a simplification may not be appropriate, particularly for the flexible forefoot. This study investigated the appropriateness of the rigid body assumption on marker clusters used to define the individual segments (tibia, hindfoot, forefoot) of a widely-used MSFM."

• Measured and estimated ground reaction forces for multi-segment foot models
"Accurate measurement of ground reaction forces under discrete areas of the foot is important in the development of more advanced foot models, which can improve our understanding of foot and ankle function. To over come current equipment limitations, a few investigators have proposed combining a pressure mat with a single force platform and using a proportionality assumption to estimate sub area shear forces and free moments."
• Kinematic analysis of a multi-segment foot model for research and clinical applications
Kinematic analysis of a multi-segment foot model for research and clinical applications:
a repeatability analysis - Oxford Foot Model

"An unbiased understanding of foot kinematics has been difficult to achieve due to the complexity of foot structure and motion. We have developed a protocol for evaluation of foot kinematics during barefoot walking based on a multi-segment foot model. Stereophotogrammetry was used to measure retroreflective markers on three segments of the foot plus the tibia."


• Relationship between motion of the hallux and the foot in cerebral palsy
"Foot deformity is a common occurrence in cerebral palsy (CP), affecting around 90% of the population. The hallux is often implicated, with valgus or adduction deformity occurring most frequently. In addition, dynamic function of the hallux during gait is often compromised. However, the relationship between motion of the hallux and the rest of the foot is unknown. The aim of this study is to investigate this relationship, and thereby improve understanding of the role of the hallux during gait in children with CP."

• Repeatability of a model for measuring multi-segment foot kinematics in children
"This study used a previously tested foot model and adapted it for use with children. A number of variations on this adapted model were implemented and tested for repeatability and accuracy on 15 healthy children on three occasions. These included redefinition of the long axes of the tibia and forefoot, assessment of the flexibility of the forefoot and evaluation of the variability of the wand marker on the heel for both static and dynamic trials."

• Repeatability of the modified Oxford foot model during gait in healthy adults
"The Oxford footmodel (OFM) is a multi-segment model for calculating hindfoot and forefoot motion. Limited information is available regarding the repeatability and error of this model in adults. Therefore the purpose of this study was to assess the intra-tester reliability of OFM hindfoot and forefoot gait kinematics in adults at initial contact (IC) and toe-off (TO)."




USA:

• A kinematic description of dynamic midfoot break in children
A kinematic description of dynamic midfoot break in children using a multi-segment foot model

"Midfoot break (MFB) is a foot deformity that occurs most commonly in children with cerebral palsy (CP), but may also affect children with other developmental disorders. Dynamic MFB develops because the muscles that cross the ankle joint are hypertonic, resulting in a breakdown and dysfunction of the bones within the foot. In turn, this creates excessive motion at the midfoot. With the resulting inefficient lever arm, the foot is then unable to push off the ground effectively, resulting in an inadequate and painful gait pattern. Currently, there is no standard quantitative method for detecting early stages of MFB, which would allow early intervention before further breakdown occurs. The first step in developing an objective tool for early MFB diagnosis is to examine the difference in dynamic function between a foot with MFB and a typical foot. Therefore, the main purpose of this study was to compare the differences in foot motion between children with MFB and children with typical feet (Controls) using a multi-segment kinematic foot model."


• A multi-segment foot model
A multi-segment foot model based on anatomically registered technical coordinate systems:
Method repeatability in pediatric feet

"Several multi-segment foot models to measure the motion of intrinsic joints of the foot have been reported. Use of these models in clinical decision making is limited due to lack of rigorous validation including inter-clinician, and inter-lab variability measures. A model with thoroughly quantified variability may significantly improve the confidence in the results of such foot models. This study proposes a new clinical foot model with the underlying strategy of using separate anatomic and technical marker configurations and coordinate systems. Anatomical landmark and coordinate system identification is determined during a static subject calibration. Technical markers are located at optimal sites for dynamic motion tracking. The model is comprised of the tibia and three foot segments (hindfoot, forefoot and hallux) and inter-segmental joint angles are computed in three planes. Data collection was carried out on pediatric subjects at two sites (Site 1: n = 10 subjects by two clinicians and Site 2: five subjects by one clinician)."


• Method repeatability and sensitivity in pediatric planovalgus feet
"A multi-segment foot model based on anatomically registered technical coordinate systems:
Method repeatability and sensitivity in pediatric planovalgus feet

Several multisegment foot models have been proposed and some have been used to study foot pathologies. These models have been tested and validated on typically developed populations; however application of such models to feet with significant deformities presents an additional set of challenges. For the first time, in this study, a multisegment foot model is tested for repeatability in a population of children with symptomatic abnormal feet. The results from this population are compared to the same metrics collected from an age matched (8–14 years) typically developing population. The modified Shriners Hospitals for Children, Greenville (mSHCG) foot model was applied to ten typically developing children and eleven children with planovalgus feet by two clinicians."