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Pain in the flexible flatfoot is a common complaint, if present it is important to find its exact location and causes Therefore, the study aimed to find differences between children with and without medial arch pain and relate them to the reduction of pain following surgical treatment. Children with idiopathic flexible flatfeet were retrospectively included in the study. All children underwent a clinical, radiographic, and gait examination. The feet were subdivided into 2 groups: asymptomatic and those with medial arch pain. Factors associated with medial arch pain were identified via t test. Significant radiological and gait parameters were correlated to the change in medial arch pain score following surgery. Included were 322 feet belonging to 177 children, with the mean age of 11.8 (SD = 2.2) years. The pain was perceived in 52% of the feet, of these, 74% in the medial arch. In the group with pain, 31 feet received a gait analysis following surgery. The radiological parameters, talus-1 and -2 metatarsal angles and the gait parameter, calcaneal lateral shift during walking showed a significant difference (p ≤.004) between the no pain and pain groups and were associated (R2 ≥0.14, p ≤.04) with the reduction in pain following surgery. The increased talus-1 and -2 metatarsal angles and the calcaneal lateral shift may cause increased tension on the soft-tissues along the medial side of the foot and may produce pain. Therapies aiming at improving the medial arch pain should be directed to normalize the talus-1 or -2 metatarsal angles and the calcaneal lateral shift. [ABSTRACT FROM AUTHOR]

Knowledge of ergonomics/human factors plays an important role in the creation and design of safety shoes and insoles, contributing to worker protection, comfort, and stability. The purpose of this study is to compare previous insole designs and analyze the plantar pressure and gait pattern kinematics using the Oxford foot model protocol. The tests were performed comparing the environments on the three rockers of the gait, represented by the heel, midfoot, and forefoot, according to the classification of foot type. The analysis of plantar pressure, regarding its total and maximum distribution, showed that the innovative insole presents a better load distribution in terms of the maximum plantar pressure exerted in the hindfoot and forefoot regions. In the biomechanical analysis of gait, the five variables studied did not show variation in the normal mechanics of the foot in any of the three environments considered. The hallux joint was the one that presented the greatest divergences with the barefoot in terms of amplitude and variability, as expected. [ABSTRACT FROM AUTHOR]

Background: Different multi-segment foot models have been used to explore the effect of foot orthoses. Previous studies have compared the kinematic output of different multi-segment foot models, however, no study has explored if different multi-segment foot models detect similar kinematic changes when wearing a foot orthoses. The aim of this study was to compare the ability of two different multi-segment foot models to detect kinematic changes at the hindfoot and forefoot during the single and double support phases of gait when wearing a foot orthosis. Methods: Foot kinematics were collected during walking from a sample of 32 individuals with and without a foot orthosis with a medial heel bar using an eight-camera motion capture system. The Oxford Foot Model (OFM) and a multi-segment foot model using the Calibrated Anatomical System Technique (CAST) were applied simultaneously. Vector field statistical analysis was used to explore the kinematic effects of a medial heel bar using the two models, and the ability of the models to detect any changes in kinematics was compared. Results: For the hindfoot, both models showed very good agreement of the effect of the foot orthosis across all three anatomical planes during the single and double support phases. However, for the forefoot, the level of agreement between the models varied with both models showing good agreement of the effect in the coronal plane but poorer agreement in the transverse and sagittal planes. Conclusions: This study showed that while consistency exists across both models for the hindfoot and forefoot in the coronal plane, the forefoot in the transverse and sagittal planes showed inconsistent responses to the foot orthoses. This should be considered when interpreting the efficacy of different interventions which aim to change foot biomechanics. [ABSTRACT FROM AUTHOR]

Knowledge of ergonomics/human factors plays an important role in the creation and design of safety shoes and insoles, contributing to worker protection, comfort, and stability. The purpose of this study is to compare previous insole designs and analyze the plantar pressure and gait pattern kinematics using the Oxford foot model protocol. The tests were performed comparing the environments on the three rockers of the gait, represented by the heel, midfoot, and forefoot, according to the classification of foot type. The analysis of plantar pressure, regarding its total and maximum distribution, showed that the innovative insole presents a better load distribution in terms of the maximum plantar pressure exerted in the hindfoot and forefoot regions. In the biomechanical analysis of gait, the five variables studied did not show variation in the normal mechanics of the foot in any of the three environments considered. The hallux joint was the one that presented the greatest divergences with the barefoot in terms of amplitude and variability, as expected.

Various neurological and musculoskeletal disorders can induce pathologic toe walking and lead to changes in foot kinematics. In this study, we analyzed the differences in foot kinematics between toe walking and heel-toe walking (HW) in able-bodied individuals. Twenty young healthy adults performed three gaits: HW, comfortable-height toe walking (CTW), and maximum-height toe walking (MTW). Oxford Foot Model was used for gait analysis. Toe walking showed increase of forefoot plantarflexion and hindfoot internal rotation compared to HW. Thus, our results may help distinguish the pathologic mechanism of the equinus gait in various disorders from the kinematic change of toe walking itself. [ABSTRACT FROM AUTHOR]

Research Question: What is the intra- and inter-assessor error of the Oxford Foot Model (OFM) during healthy adult walking when applied by three assessors with different professional backgrounds and lower limb marker placement experience, not native to the originators of the model and with no prior clinical experience of the model?Background: No previous OFM studies have examined the repeatability of more than two assessors with different backgrounds, and many of the studies have been conducted by the model originators METHODS: The OFM was applied to ten healthy adults on three separate occasions by three different assessors with varied professional experience and no prior involvement with the OFM (other than local training). Participants walked at self-selected speeds and intra/inter assessor error was calculated using the SEM + 95% upper confidence limit.Results: Inter-assessor errors ranged from 2.2° to 5.5° whereas intra-assessor errors fell between 1.8° and 5.5°. The error difference between assessors over the same joint angle varied from 0.4° (hindfoot/tibia dorsiflexion) to 1.5° (hindfoot/tibia inversion). The percentage of error to total range of motion varied from 11% (hindfoot/tibia dorsiflexion) to 126% (forefoot/hindfoot adduction).Significance: Based on commonly used recommendations, the OFM is a largely repeatable tool for measuring foot kinematics during healthy adult walking when applied by assessors with no prior OFM experience, varied experience and not native to the model originators. Intra-assessor error was lower for assessors with prior anatomical knowledge and significant lower limb marker placement experience. The proportion of inter-assessor error to movement exceeded 50% of the total range of motion for four movements, notably forefoot/hindfoot adduction (126%). As such, this movement cannot be recommended as an outcome measure. Inter- and intra-assessor error, specific to each laboratory, should be considered, along with the proportion of error to range of motion when interpreting patient data. [ABSTRACT FROM AUTHOR]

Background: The foot arch plays an important role in propulsion and shock absorption during walking and running; however, the relationship among the foot arch, metatarsal locking theory, and nature of the windlass mechanism (WM) remain unclear.Research Question: What are the differences in the kinematic relationship between the foot arch, hindfoot, and hallux during walking and running?Methods: Relative angles within the foot were measured in 18 healthy men using the Oxford foot model (OFM). Data for barefoot walking at a comfortable speed and rearfoot running at 2.0 m/s were collected. Angles of the forefoot relative to the hindfoot (OFM-arch), hallux relative to the forefoot (Hallux) on the sagittal plane, and hindfoot relative to the shank (Hindfoot) on three anatomical planes were obtained. The medial longitudinal arch (MLA) angle was calculated to verify that OFM-arch can substitute the MLA angle. Each parameter was subjected to cross-correlation analysis and Wilcoxon signed-rank tests to examine the relationship with OFM-arch and compare them during walking and running.Result: OFM-arch was similar to the conventional MLA projection angle in both trials (gait: 0.79, running: 0.96 p < 0.01). Synchronization of the OFM-arch and Hallux angles was higher in running than in walking (gait: -0.09, running: -0.75 p < 0.01). Hindfoot supination was unrelated to OFM-arch. Hindfoot angle on the transverse plane exhibited a moderate relationship with OFM-arch, indicating different correlations in walking and running (gait: 0.63, running: -0.68 p < 0.01).Significance: The elevation of the foot arch due to hallux dorsiflexion differed during walking and running; hence, other factors besides WM (such as intrinsic muscles) may affect the foot arch elevation during running. The hindfoot in the frontal plane does not contribute to arch raising and foot stability during running; it features different relationships with OFM-arch during walking and running. [ABSTRACT FROM AUTHOR]

Abstract Background Different multi‐segment foot models have been used to explore the effect of foot orthoses. Previous studies have compared the kinematic output of different multi‐segment foot models, however, no study has explored if different multi‐segment foot models detect similar kinematic changes when wearing a foot orthoses. The aim of this study was to compare the ability of two different multi‐segment foot models to detect kinematic changes at the hindfoot and forefoot during the single and double support phases of gait when wearing a foot orthosis. Methods Foot kinematics were collected during walking from a sample of 32 individuals with and without a foot orthosis with a medial heel bar using an eight‐camera motion capture system. The Oxford Foot Model (OFM) and a multi‐segment foot model using the Calibrated Anatomical System Technique (CAST) were applied simultaneously. Vector field statistical analysis was used to explore the kinematic effects of a medial heel bar using the two models, and the ability of the models to detect any changes in kinematics was compared. Results For the hindfoot, both models showed very good agreement of the effect of the foot orthosis across all three anatomical planes during the single and double support phases. However, for the forefoot, the level of agreement between the models varied with both models showing good agreement of the effect in the coronal plane but poorer agreement in the transverse and sagittal planes. Conclusions This study showed that while consistency exists across both models for the hindfoot and forefoot in the coronal plane, the forefoot in the transverse and sagittal planes showed inconsistent responses to the foot orthoses. This should be considered when interpreting the efficacy of different interventions which aim to change foot biomechanics.

Abstract Background Detailed kinematics of the foot has been frequently reported on in the literature, specifically using various multi-segment foot models. It is important to identify the reliability of a multi-segment foot model in a population of mixed genders and activity levels, while walking in commonly used footwear. The main objective of this study was to investigate the between-day reliability and within-session variability of the Oxford Foot Model (OFM) while walking in a neutral cushioning shoe. Methods A 7-camera Vicon motion capture system was used along with 29 passive reflective markers, placed on the participant to examine the multi-segment foot kinematics of the left foot using the OFM. Windows were cut in New Balance 840 shoes following reports from a previous investigation to maintain shoe integrity during testing. Two walking sessions on separate days were collected for 12 healthy participants, with an average total of 22 gait cycles per day. Results ICCs ranged from 0.020 to 0.964 for between-day reliability, and within-session ICC values ranged from 0.268 to 0.985. Between-day ICC values of the relative measures (excursion and range of motion (ROM)) were higher than the absolute angle measures (angle at foot strike and peak angle). Largest differences were measured in the transverse plane, and the smallest differences in the sagittal plane. Bland-Altman plots revealed best agreement in the frontal and sagittal planes. SEM values ranged from 0.04 to 3.5 for the between-day reliability. Conclusions Between-day reliability and within-session variability were comparable to previous studies for adults walking barefoot and shod. This research demonstrates that the OFM can produce reliable data when applied to the assessment of a shod foot.

Background: Clinical tests of foot posture and mobility are not strongly related to the dynamic kinematics of the foot during gait. These measures may be more directly related to foot and ankle kinetics. The supination resistance test (SRT) is a clinical test that may more directly measure forces acting on the weightbearing foot to provide clinicians with insight about the loading of foot structures.Research Question: What is the relationship between the SRT in relaxed calcaneal stance and in single-leg-stance and the kinetics and kinematics of the foot and ankle during gait?Methods: 10 healthy adults between the ages of 18 and 65 were recruited to participate in this study. Three-dimensional motion analysis was performed using the Oxford Foot Model during gait. The results of the SRT were compared with peak midfoot and ankle joint moments, power generation and absorption, joint angles, and peak angular velocities and accelerations. Correlation coefficients were calculated to assess the strength of relationships between these variables and the SRT.Results: The SRT demonstrated significant relationships with several variables. In relaxed calcaneal stance, the SRT was inversely related to maximum midfoot pronation moments (r = -0.51), maximum midfoot plantarflexion moments (rho = -0.71), and peak midfoot power generation (r = -0.61). In single-leg-stance, the SRT was significantly related to maximum midfoot plantarflexion moments (rho = -0.55) and peak midfoot power generation (r = -0.47).Significance: The SRT is significantly associated to several kinetic variables that quantify midfoot loading during gait. Interventions that decrease supination resistance may have the potential to increase midfoot power generation. [ABSTRACT FROM AUTHOR]

Wearing high heels is thought to lead to various foot disorders and injuries such as metatarsal pain, Achilles tendon tension, plantar fasciitis and Haglund malformation. However, there is little available information explaining the specific mechanisms and reasons why wearing high heels causes foot deformity. Therefore, the purpose of this study was to investigate the foot kinematics of high heel wearers and compare any differences with barefoot individuals using the Oxford Foot Model (OFM). Fifteen healthy women aged 20-25 years were measured while walking barefoot and when wearing high heels. The peak value of angular motion for the hallux with respect to the forefoot, the forefoot with respect to the hind foot, and the hind foot with respect to the tibia were all analyzed. Compared to the barefoot, participants wearing high heels demonstrated larger hallux dorsiflexion (22.55∘± 1.62∘ VS 26.6∘± 2.33∘ for the barefoot; P= 0.001), and less hallux plantarflexion during the initial stance phase (-4.86∘± 2.32∘ VS -8.68∘± 1.13∘; P< 0.001). There were also greater forefoot adduction (16.15∘± 1.37∘ VS 13.18∘± 0.79∘; P< 0.001), but no significant differences were found in forefoot abduction between the two conditions. The hind foot demonstrated a larger dorsiflexion in the horizontal plane (16.59∘± 1.69∘ VS 12.08∘± 0.9∘; P< 0.001), greater internal rotation (16.72∘± 0.48∘ VS 7.97∘± 0.55∘; P< 0.001), and decreased peak hind foot extension rotation (-5.49∘± 0.69∘ VS -10.73∘± 0.42∘; P= 0.001). These findings complement existing kinematic evidence that wearing high heels can lead to foot deformities and injuries. [ABSTRACT FROM AUTHOR]

Introduction: Vertical ground reaction forces (VGRFs) are altered in patients after foot trauma. It is not known if this correlates with ankle kinematics. The aim of this study was to analyze VGRFs in patients after calcaneal trauma and correlate them to patient-reported outcome measures (PROMs), radiographic findings and kinematic analysis, using a multi-segment foot model. In addition, we determined the predictive value of VGRFs to identify patients with altered foot kinematics.Methods: Thirteen patients (13 feet) with displaced intra-articular calcaneal fractures, were included an average of two years after trauma surgery. PROMs, radiographic findings on postoperative computed tomography scans, gait analysis using the Oxford foot model and VGRFs were analysed during gait. Results were compared with those of 11 healthy subjects (20 feet). Speed was equal in both groups, with healthy subjects walking at self-selected slow speed (0.94±0.18m/s) and patients after surgery walking at self-selected normal speed (0.94±0.29m/s). ROC curves were used to determine the predictive value.Results: Patients after calcaneal surgery showed a lower minimum force during midstance (p=0.004) and a lower maximum force during toe-off (p=0.011). This parameter correlated significantly with the range of motion in the sagittal plane during the push-off phase (r 0.523, p=0.002), as well as with PROMs and with postoperative residual step-off (r 0.423, p=0.016). Combining these two parameters yielded a cut-off value of 193% (p<0.001), area under the curve 0.93 (95%confidence interval 0.84-1.00).Conclusion: Patients after calcaneal fracture showed lower minimum force during midstance and lower maximum force during toe-off compared to healthy subjects. This lower maximum force during push-off correlated significantly with PROMs, range of motion in the sagittal plane during push-off and radiographic postoperative residual step-off in the posterior facet of the calcaneal bone. VGRFs are a valuable screening tool for identifying patients with altered gait patterns. [ABSTRACT FROM AUTHOR]

Over-pronated feet are common in adults and are associated with lower limb injuries. Studying the foot muscle morphology and foot kinematic patterns is important for understanding the mechanism of over-pronation related injuries. The aim of this study is to compare the foot muscle morphology and foot inter-segmental kinematics between recreational runners with normal feet and those with asymptomatic over-pronated feet. A total of 26 recreational runners (17 had normal feet and 9 had over-pronated feet) participated in this study and their foot type was assessed using the 6-item Foot Posture Index. Selected foot muscles were scanned using an ultrasound device and the scanned images were processed to measure the thickness and cross-sectional area of the muscles. Muscles of interest include abductor hallucis, abductor digiti minimi, flexor digitorum brevis and longus, tibialis anterior and peroneus muscles. Foot kinematic data during walking was collected using a 3D motion capture system incorporating the Oxford Foot Model. The results show that individuals with over-pronated feet have larger size of abductor hallucis, flexor digitorum brevis and longus and smaller abductor digiti minimi than controls. Higher rearfoot peak eversion and forefoot peak supination during walking were observed in individuals with over-pronated feet. However, during gait the forefoot peak abduction was comparable. These findings indicate that in active asymptomatic individuals with over-pronated feet, the foot muscle morphology is adapted to increase control of the foot motion. The morphological characteristics of the foot muscles in asymptomatic individuals with over-pronated feet may affect their foot kinematics and benefit prevention from injuries. [ABSTRACT FROM AUTHOR]

Background: Arthrodesis of the first metatarsophalangeal (MTP1) joint is an intervention often used in patients with severe MTP1 joint osteoarthritis and relieves pain in approximately 80% of these patients. The kinematic effects and compensatory mechanism of the foot for restoring a more normal gait pattern after this intervention are unknown. The aim of this study was to clarify this compensatory mechanism, in which it was hypothesized that the hindfoot and forefoot would be responsible for compensation after an arthrodesis of the MTP1 joint. Methods: Gait properties were evaluated in 10 feet of 8 patients with MTP1 arthrodesis and were compared with 21 feet of 12 healthy subjects. Plantar pressures and intersegmental range of motion were measured during gait by using the multisegment Oxford Foot Model. Pre- and postoperative X-rays of the foot and ankle were also evaluated. Results: The MTP1 arthrodesis caused decreased eversion of the hindfoot during midstance, followed by an increased internal rotation of the hindfoot during terminal stance, and ultimately more supination and less adduction of the forefoot during preswing. In addition, MTP1 arthrodesis resulted in a lower pressure time integral beneath the hallux and higher peak pressures beneath the lesser metatarsals. A mean dorsiflexion fusion angle of 30 ± 5.4 degrees was observed in postoperative radiographs. Conclusion: This study demonstrated that the hindfoot and forefoot compensated for the loss of motion of the MTP1 joint after arthrodesis in order to restore a more normal gait pattern. This resulted in a gait in which the rigid hallux was less loaded while the lesser metatarsals endured higher peak pressures. Further studies are needed to investigate whether this observed transfer of load or a preexistent decreased compensatory mechanism of the foot can possibly explain the disappointing results in the minority of the patients who experience persistent complaints after a MTP1 arthrodesis. Level of Evidence: Level III, comparative series. [ABSTRACT FROM AUTHOR]

The aim of the present study was to analyse the reproducibility of the Oxford Foot Model (OFM) when used with healthy adults during two clinical tests, i.e., the Anterior Step Down Test (SDA) and the Lateral Step Down Test (SDL). Five healthy participants (one male and four females, 10 limbs in total) with a mean age of 22.2 (19-30) years were assessed in four sessions of tests conducted at intervals of one week. Two independent examiners performed two of the sessions of each of the tests. For each session (intra-day), nine repetitions of each clinical test (SDA and SDL) were performed. After an interval of three hours, the data were collected again. The tests were conducted again after an interval of one week using the same experimental conditions. The intra- and inter-session repeatabilities of the ranges of motion of the feet were determined according to the standard error of measurement (SEM) for each examiner and for the differences between the examiners. The repeatabilities of the results were high for both of the conducted tests. The SEM results were as follows: 0.47-1.94° for the intra-examiner assessment (SDA), 0.55-2.01° for the inter-examiner comparison (SDA), 0.44-2.43° for the intra-examiner assessment (SDL), and 0.54-1.89° for the inter-examiner comparison (SDL). The OFM model was shown to be reproducible in terms of assessing the range of motion of healthy adults during functional tests (SDA and SDL). [ABSTRACT FROM AUTHOR]

The purpose of this paper was to systematically assess the effect of Oxford Foot Model (OFM) marker misplacement on hindfoot relative to tibia, and forefoot relative to hindfoot kinematic calculations during the stance phase of gait. Marker trajectories were recorded with an 8-camera motion analysis system (Vicon Motion Systems Ltd., UK) and ground reaction forces were recorded from three force platforms (AMTI, USA). A custom built marker cluster consisting of 4 markers in a square arrangement (diagonal distance 2 cm) was used to assess the effect of marker misplacement in the superior, inferior, anterior and posterior direction for the sustentaculum tali (STL), the proximal 1st metatarsal (P1M), distal 5th metatarsal (D5M), proximal 5th metatarsal (P5M) and lateral calcaneus (LCA) markers. In addition manual movement of the heel complex 1 cm superiorly, inferiorly, medially and laterally, and also an alignment error of 10° inversion and 10° eversion was assessed. Clinically meaningful effects of marker misplacement were determined using a threshold indicating the minimal clinically important difference. Misplacement of the heel-wand complex had the most pronounced effect on mean kinematic profiles during the stance phase across all degrees-of-freedom with respect to hindfoot-tibia and forefoot-hindfoot angles. Vertical marker misplacement of the D5M and P5M markers affected the sagittal plane, and to a lesser extent frontal plane, forefoot-hindfoot kinematics. In conclusion, the OFM is highly sensitive to misplacement of the heel-wand complex in all directions and the P5M marker in the vertical direction. [ABSTRACT FROM AUTHOR]

Objectives To assess the compensations of proximal motion for forefoot varus (FV) by analysing the lower limb kinematics in standing and walking. Methods A population of children ( n = 375) underwent a goniometric evaluation of forefoot and hindfoot frontal-plane alignment (neutral/varus/valgus) drawn from a randomly selected primary school of Saragossa (Spain). Two groups were extracted: 1) forefoot varus group (FVG) ( n = 30 FV children); 2) control group (CG) ( n = 21 forefoot neutral children). The Oxford Foot Model and a conventional lower limb model were used to obtain kinematics while standing and walking. The Oxford Foot Model is a specific biomechanical model developed for the analysis of three-dimensional mobility of the ankle, hindfoot and forefoot in children. It is specifically adapted for paediatric use and offers normative data. Data acquisition was performed using a six-camera motion capture system. Kinematic variables were compared between both groups. Correlations between forefoot and hindfoot inversion/eversion with the rest of the kinematic variables in the FVG were carried out. Results FV children presented larger hindfoot eversion with flattening of medial longitudinal arch and larger hindfoot, knee and hip flexion, while standing and walking. Moreover, they walked with a higher anterior pelvis tilt and hip external rotation, and with smaller stride time and length and higher cadence. There was high correlation between forefoot inversion and hindfoot eversion during standing and some correlation between both forefoot inversion and hindfoot eversion and the rest of variables analysed during gait. Conclusions The results support the existence of a compensatory pronation of the subtalar joint. This is thought to occur during weight-bearing in order to achieve full contact of all metatarsal heads with the ground, and is probably responsible of an altered kinematic chain in the lower limb in standing and walking. FV correction might help to prevent this potentially harmful hindfoot compensation and the subsequent altered lower extremity kinematic chain. [ABSTRACT FROM AUTHOR]

Background: Patients suffering from juvenile idiopathic arthritis (JIA) frequently have affected ankle joints, which can lead to foot deformities such as pes planovalgus (JIA-PPV). Usually, JIA-PPV is diagnosed by examining the foot in non-weightbearing or in weightbearing, static condition. However, functional limitations typically appear during dynamic use in daily activities such as walking. The aim of this study was to quantify the pathophysiology of JIA-PPV in both static and dynamic condition, i.e. in upright standing and during the stance phase of walking using three-dimensional (3d) gait analysis. Methods: Eleven JIA patients (age = 12y) with at least one affected ankle joint and fixed pes planovalgus (≥5°) were compared to healthy controls (CG) (n = 14, age = 11y). Kinematic and kinetic data were obtained in barefoot standing and walking condition (1.1-1.3 m/s) with an 8-camera 3d motion analysis system including two force-plates and one pressure distribution plate. All participants were prepared using reflecting markers according to the Oxford Foot and Plug-in-Gait Model. Results were compared using the Mann-Whitney-U-test and Wilcoxon signed-rank test (p < 0.05). Results: In comparison to CG, JIA-PPV had an excessive hindfoot/tibia eversion (p < 0.001) and a forefoot/hindfoot supination (p < 0.001) in both static and walking condition. JIA-PPV showed a greater hindfoot/tibia eversion during walking (midstance) compared to standing (p = 0.021) in contrast to CG. The arch index, measured by plantar pressure distribution, indicates a reduced arch height in JIA-PPV (p = 0.007). Patients had a lower maximum dorsiflexion of hindfoot/tibia (p = 0.001) and a lower plantarflexion of forefoot/hindfoot (p = 0.028), both when standing and walking. The kinetic results showed lower maximum ankle dorsiflexion moments (p < 0.037) as well as generated ankle power (p = 0.086) in JIA-PPV. Conclusions: The pathophysiology of JIA-PPV during walking indicated that excessive hindfoot eversion produces accessory symptoms such as a reduced arch height, increased forefoot supination and reduced propulsion effect of the ankle. Muscular and coordinative insufficiency caused by arthritis can lead to the observed increased hindfoot eversion from static to dynamic condition. Conventional static or passive foot examination techniques probably underestimate deformity in JIA pes planovalgus. 3d gait analysis might be helpful in early diagnosis of this condition, especially in JIA patients with affected ankle joints. [ABSTRACT FROM AUTHOR]

The foot plays an important role as it is the only connection that the human body has with the floor when walking, running, etc. The two main techniques commonly used to study the lower limb in biomechanics are gait analysis and plantar pressure measurements. However, they require different settings: One requires barefoot experimentation and the other requires the subject to be shod. The method proposed in this paper attempts to solve this problem by designing shoes that can mimic both conditions. This allows the analysis of both approaches simultaneously and therefore provides valuable inputs for the development of a well validated model of the foot. [ABSTRACT FROM AUTHOR]

Background Flatfoot is a common variant of foot posture. Whilst usually benign, in some children flatfoot is accompanied by pain and functional complaints. Comparisons between the posture of asymptomatic and symptomatic flat feet are few. If a difference does exist, it may help understand symptoms and guide management. Methods This paper investigated differences in lower limb posture between neutral and flat feet with and without symptoms during standing using the multi-segment Oxford Foot Model. 97 children between five and 18 years old were assessed by a physiotherapist; each foot was classified into one of four categories: asymptomatic neutral (n = 88), asymptomatic mild flatfoot (n = 47), asymptomatic flatfoot (n = 29), or symptomatic flatfoot (n = 30). For each child, Oxford Foot Model markers were applied, and mean values of 11-Euler angles at the foot, ankle, and knee joints during standing were calculated. Analysis of variance and post-hoc tests were used to identify differences between groups. Findings Hindfoot eversion was significantly increased ( P < 0.001) in children with asymptomatic and, to a greater extent, symptomatic flatfoot. The forefoot was significantly more abducted ( P < 0.001) in the symptomatic than asymptomatic groups, and in the flat than neutral group. The forefoot was more supinated relative to the hindfoot in the flatfoot groups (P = 0.023), although post-hoc analysis did not identify specific group differences. Interpretation Hindfoot eversion and forefoot abduction were much greater in the symptomatic population. The differences in foot alignment may relate to the presence of symptoms. [ABSTRACT FROM AUTHOR]

Turning is a common locomotor task essential to daily activity; however, very little is known about the forces and moments responsible for the kinematic adaptations occurring relative to straight-line gait in typically developing children. Thus, the aims of this study were to analyse ground reaction forces (GRFs), ground reaction free vertical torque (TZ), and the lower-limb joint kinetics of 90° outside (step) and inside (spin) limb turns. Step, spin, and straight walking trials from fifty-four typically developing children were analysed. All children were fit with the Plug-in Gait and Oxford Foot Model marker sets while walking over force plates embedded in the walkway. Net internal joint moments and power were computed via a standard inverse dynamics approach. All dependent variables were statistically analysed over the entire curves using the mean difference 95% bootstrap confidence band approach. GRFs were directed medially for step turns and laterally for spin turns during the turning phase. Directions were reversed and magnitudes decreased during the approach phase. Step turns showed reduced ankle power generation, while spin turns showed large TZ. Both strategies required large knee and hip coronal and transverse plane moments during swing. These kinetic differences highlight adaptations required to maintain stability and reorient the body towards the new walking direction during turning. From a clinical perspective, turning gait may better reveal weaknesses and motor control deficits than straight walking in pathological populations, such as children with cerebral palsy, and could potentially be implemented in standard gait analysis sessions. [ABSTRACT FROM AUTHOR]

Abstract: Treatment of asymptomatic flexible flatfeet is a subject of great controversy. The purpose of this study was to examine foot function during walking in symptomatic (SFF) and asymptomatic (ASFF) flexible flatfeet. Thirty-five paediatric and juvenile patients with idiopathic flexible flatfeet were recruited from an orthopaedic outpatient department (14 SFF and 21 ASFF). Eleven age-matched participants with typically developing feet served as controls (TDF). To study foot function, 3D multi-segment foot kinematics and ankle joint kinetics were captured during barefoot gait analysis. Overall, alterations in foot kinematics in flatfeet were pronounced but differences between SFF and ASFF were not observed. Largest discriminatory effects between flatfeet and TDF were noticed in reduced hindfoot dorsiflexion as well as in increased forefoot supination and abduction. Upon clinical examination, restrictions in passive dorsiflexion in ASFF and SFF were significant. During gait, the hindfoot in flatfeet (both ASFF and SFF) was more everted, but less flexible. In sagittal plane, limited hindfoot dorsiflexion of ASFF and SFF was compensated for by increased forefoot mobility and a hypermobile hallux. Concerning ankle kinetics, SFF lacked positive joint energy for propulsion while ASFF needed to absorb more negative ankle joint energy during loading response. This may risk fatigue and overuse syndrome of anterior shank muscles in ASFF. Hence, despite a lack of symptoms flatfoot deformity in ASFF affected function. Yet, contrary to what was expected, SFF did not show greater deviations in 3D foot kinematics than ASFF. Symptoms may rather depend on tissue wear and subjective pain thresholds. [Copyright &y& Elsevier]

Highlights: [•] The biomechanics of turning in typically developing children were investigated. [•] Spatio-temporal and kinematic data showed differences compared to straight gait. [•] These findings provide insight into the adaptations required for turning. [•] The management of gait disorders may be improved via analysis of turning. [Copyright &y& Elsevier]

Abstract: Multi-segment foot models are increasingly being used to evaluate intra and inter-segment foot kinematics such as the motion between the hindfoot/tibia (ankle) and the forefoot/hindfoot (midfoot) during walking. However, kinetic analysis have been mainly restricted to one-segment foot models and could be improved by considering a multi-segment approach. Therefore, the aims of this study were to (1) implement a kinetic analysis of the ankle and theoretical midfoot joints using the existing Oxford Foot Model (OFM) through a standard inverse dynamics approach using only marker, force plate and anthropometric data and (2) to compare OFM ankle joint kinetics to those output by the one-segment foot plugin-gait model (PIG). 10 healthy adolescents fitted with both the OFM and PIG markers performed barefoot comfortable speed walking trials over an instrumented walkway. The maximum ankle power generation was significantly reduced by approximately 40% through OFM calculations compared to PIG estimates (p<0.001). This result was not caused by a decrease in OFM computed joint moments, but by a reduction in the angular velocity between the tibia/hindfoot (OFM) compared to the tibia/foot (PIG) (p<0.001). Additionally, analysis revealed considerable midfoot loading. One-segment foot models overestimate ankle power, and may also overestimate the contribution of the triceps surae. A multi-segment approach may help quantify the important contribution of the midfoot ligaments and musculature to power generation. We therefore recommend the use of multi-segment foot models to estimate ankle and midfoot kinetics, especially when surgical decision-making is based on the results of three-dimensional gait analysis. [Copyright &y& Elsevier]

[Purpose] The purpose of this study was to investigate the characteristics of gait in patients with hallux valgus and the effects on the joints of the lower extremities (hip, knee and ankle). [Subjects] The patient was a 69-year-old female diagnosed with rheumatoid arthritis (RA) including hallux valgus. The patient had a chief complaint of pain on the medial side of the right hallux in gait. [Methods] Gait analyses, using the VICON-MX systems were performed preoperatively and postoperatively at 6 months. [Results] The postoperative valgus of knee moments decreased, and valgus of ankle moments had increased on the operated side. The varus of knee moments on the non-operated side was higher than on the operated side. [Conclusion] The results revealed instability in the lateral direction of the lower extremity with deformity of the foot. Hallux valgus associated with valgus knee deformity on the operated and varus on the non-operated side is a potential cause of osteoarthritis of the knee. We should be careful not only to prevent the recurrence of hallux valgus on the operated side but also osteoarthritis of the knee on the opposite side. These results are useful indicators for rehabilitation management of hallux valgus. [ABSTRACT FROM AUTHOR]

Abstract: 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). Foot posture in 19 participants was documented as normal-arched (n =10) or flat-arched (n =9) using a foot screening protocol incorporating measurements from weightbearing antero-posterior and lateral foot radiographs. Differences between the groups in triplanar motion of the tibia, rearfoot and forefoot during walking were evaluated using a three-dimensional motion analysis system incorporating a multi-segment foot model (OFM). Participants with flat-arched feet demonstrated greater peak forefoot plantar-flexion (−13.7°±5.6° vs −6.5°±3.7°; p =0.004), forefoot abduction (−12.9°±6.9° vs −1.8°±6.3°; p =0.002), and rearfoot internal rotation (10.6°±7.5° vs −0.2°±9.9°; p =0.018) compared to those with normal-arched feet. Additionally, participants with flat-arched feet demonstrated decreased peak forefoot adduction (−7.0°±9.2° vs 5.6°±7.3°; p =0.004) and a trend towards increased rearfoot eversion (−5.8°±4.4° vs −2.5°±2.6°; p =0.06). These findings support the notion that flat-arched feet have altered motion associated with greater pronation during gait; factors that may increase the risk of overuse injury. [Copyright &y& Elsevier]

Abstract: Background: 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. Method: Eight healthy children were tested twice at the gait laboratory. Foot kinematics from this study were plotted against those from an earlier repeatability study and repeatability statistics calculated for the three rockers of stance phase and swing phase. Results: Foot kinematics from this study and an earlier repeatability study produced similar kinematic patterns and joint angle ranges, but there were offsets in the absolute joint angles in the frontal and transverse planes. Relative and absolute repeatability were best in the sagittal plane (flexion/extension) with the poorest repeatability in the transverse plane (rotation and abduction/adduction). There was little difference in repeatability between the three rockers. Typical error of measurement varied between planes and segments from 0.9° for maximum forefoot dorsiflexion in second rocker to 8.6° for maximum hindfoot internal rotation in first rocker. Discussion: Repeatability varied markedly between planes and segments but was consistent throughout the gait cycle. Further studies are needed to determine the inter-centre repeatability and validity of the model. [Copyright &y& Elsevier]

Ankle fractures involving the posterior malleolus generally lead to worse outcome. However, no studies on gait in trimalleolar ankle fractures have evaluated the influence of size and comminution of the posterior malleolar fragment. We expected patients with more severely comminuted posterior malleolus, more severe fracture type and larger posterior fragment to have reduced gait kinematics and poorer patient-reported outcomes. 26 trimalleolar ankle fracture patients were compared with 14 healthy controls and kinematically analyzed using the Oxford Foot Model. Functional outcome was based on 4 patient reported outcome questionnaires. Effects of posterior fragment size, comminution and Haraguchi fracture classification were determined on conventional and 3D CT-scans. Trimalleolar patients had lower walking speed and reduced range of motion between the hindfoot and tibia in both loading and push-off phases in the sagittal and transverse planes. The range between the hindfoot and tibia in the sagittal plane in the push-off phase correlated significantly with patient reported outcomes. The absolute and relative surface area of the posterior fragment on conventional CT-scans and 3D CT-scans, correlated significantly with range of motion. Patients with a posterior malleolus size >10% of the posterior malleolus had lower flexion-extension between forefoot and hindfoot during loading phase than patients with a size ≤10%. Trimalleolar fractures reduce walking speed and range of motion in the talocrural joint. Reduced range in the talocrural joint is associated with poorer outcomes. Posterior fragment size correlated significantly with range of motion in talocrural and midfoot joints and with patient reported outcomes. Level of evidence: Level 3, retrospective study. • Malleolus tertius fracture size has impact on the range of motion of the ankle. • Patients with trimalleolar fractures have a lower walking speed. • Trimalleolar ankle fractures have decreased range of motion talocrural. • Decreased range of motion talocrural is related to worse functional outcome. [ABSTRACT FROM AUTHOR]