Forefoot Angle Research Articles

CFD-based optimization of a displacement trimaran hull for improving its calm water and wavy condition resistance

This paper presents a multi-objective shape optimization approach for improving the bow region of a trimaran ship hull. A CFD-based design study is conducted to reduce the total resistance of trimaran ship hull in calm water and wavy condition. Accordingly, a practical multi-objective optimization platform is established and developed for ship hull modification. In addition, the hullform of a displacement trimaran ship with inverted bow is modified as a case study. Six objective functions are utilized in the present study by considering the weighted sum optimization method. Reduction of total resistance at two cruise and sprint speeds in calm water, reduction of resistance in two different wave conditions, and two cruise and sprint speeds are the six objectives of the study. Two aspects of ship hydrodynamics, resistance, and seakeeping are the disciplines that are considered through the proposed optimization process. Ship hull parametrization is performed by Arbitrary Shape Deformation (ASD) technique that defines the input variables for optimization process. The geometry reconstruction step connects to CFD solver in order to calculate the response of the optimization cycle. An innovative Simcenter SHERPA algorithm is employed to optimize the design objectives. The optimization results show a 3.14% reduction in the aggregated objective function. Generated waves around the hulls of the optimized trimaran have constructive interaction and diminish each other in calm water. A forefoot angle and sharper nose are created at bow region of the optimized hullform. Moreover, the comparison between baseline and optimized trimaran hull confirms the validity of the proposed optimization design strategy.

Differences in rearfoot, midfoot, and forefoot kinematics of normal foot and flatfoot during running.

Flatfoot is a common foot deformity, which could contribute to running injuries such as medial tibial stress syndrome. Intrafoot kinematics of flatfoot during walking have often been documented using multisegment foot models. However, the intrafoot kinematics of flatfoot during running remains unclear, despite the possible relationship between flatfoot and running injuries. We aimed to clarify rearfoot, midfoot, and forefoot kinematics when running in participants with normal foot and flatfoot. Participants with the normal foot (n = 14) and flatfoot (n = 14) were asked to runover-ground at their preferred speed. Three-dimensional kinematics of the rearfoot, midfoot, and forefoot during running were calculated based on the Rizzoli foot model. A two-sample t-test of statistical parametric mapping was performed to determine differences between normal foot and flatfoot in time histories of intrafoot kinematics during running. No differences were found between groups in characteristics and spatiotemporal parameters. In the frontal rearfoot angle, a significantly increased eversion from 24% to 100% (p < .001) was observed in the flatfoot compared to the normal foot. At the midfoot angle, a significantly increased eversion from 0% to 4% (p < .049) and 21% to 100% (p < .001) was observed in the flatfoot compared to the normal foot. At the forefoot angle, a significantly increased inversion from 6% to 17% (p < .047) was observed in the flatfoot compared to the normal foot. These findings may be useful to explain why flatfoot could contribute to running injuries such as medial tibial stress syndrome.

The Relationship Between Forefoot Stiffness And Angular Kinematics During The Early Stance Phase Of Running.

PURPOSE: The purpose of this study was to determine if a relationship between forefoot stiffness and intersegmental foot kinematics exists. We hypothesized runners with high stiffness values would exhibit decrease foot motion. METHODS: A convenience sample of 20 asymptomatic recreational runners participated in this study. At the completion of a warm-up protocol, subjects underwent a measurement of their non-weight bearing midfoot torsional stiffness using a foot torsion measurement device. Retroreflective markers were placed over select bony landmarks located on the subject’s lower legs and feet and then recorded using an 18-camera motion analysis system sampling at 240 Hz while running at their self-selected speed. Data analysis: Torsion-angle curves were fit with a one-degree polynomial and the intercepts and first term coefficients (FTC) recorded. The rearfoot and forefoot three-dimensional angular kinematics of the first third of the stance phase of the running trials were obtained for each subject. A linear regression model was used to assess the relationship between the maximum eversion and inversion rearfoot and forefoot angles and the FTC. The statistical level of significance for this study was set at the p = .05 level. RESULTS: The mean eversion and inversion FTC were -0.44 ± 0.44 and -0.08 ± 0.20 Nm/degree. The mean maximum rearfoot eversion and inversion angles were 2.0 ± 2.1 and 1 ± 2.3 degrees, respectively. The mean maximum forefoot inversion and eversion angles were 1.0 ± 2.4 and 1.0 ± 2.3 degrees, respectively. The regression model did not reveal a significant relationship (p > .05) between the eversion and inversion FTC and the kinematic variables. CONCLUSIONS: During the first third of the stance phase of running passive stiffness of the foot does not appear to be related to dynamic motion.

Inter-observer and intra-observer reliability in the radiographic measurements of paediatric forefoot alignment

BackgroundFoot bones in children have more rounded shapes in radiograms than adults. Thus, the goal of this work was assessing inter- and intra-observer reliability in paediatric forefoot angle measurements. Material and methodsSix forefoot angles in 34 AP standing paediatric foot radiographs were measured by 5 researchers. A classic statistical analysis with use of IBM SPSS Statistics 25 was performed and a new method with two-way analysis of variance was applied. ResultsResults of statistical analysis revealed the properties of a subjective assessment related to specific angles. Kilmartin’s angle, calcaneus-fifth metatarsal angle and first ray angle are the most reliable; metatarsus adductus angle should be used with great caution in pediatric population. Engel’s angle is the most difficult for measuring and measurement error is the highest. ConclusionThe power of paediatric forefoot measurements is various. Several angles are reliable, while Engle’s angle is the most doubtful.

A biomechanical assessment of the acute hallux abduction manipulation intervention

BackgroundNaturally aligned toes, particularly hallux, have reported with gripping functions during locomotion, thus expanding the forefoot loading area. Research questionThe purpose of this study was aimed to investigate the influence of hallux abduction manipulation on the foot plantar pressure distribution and inter-segment kinematic alterations. MethodsThirteen subjects participated in this toe manipulation study. A Footscan® pressure plate and Vicon motion capture system were utilized for the measurement of plantar pressure distribution and lower extremity and foot inter-segment kinematics during walking and running. Paired-sample t-test from statistical parametric mapping 1d was used to check the kinematic significance. ResultsPeak pressure in third metatarsal (M3) increased significantly during walking under manipulation. Contact area increased in second metatarsal (M2) with manipulation during running. Peak pressure and pressure-time integral illustrated significant increases in M3, and the maximum force and impulse in fourth metatarsal (M4) increased significantly. Arch height index increased while walking with toe manipulation. The foot progression angle in the frontal plane showed significant decrease in mid-swing phase during walking and significant increase in mid-stance phase during running. The hallux relative to forefoot angles presented higher axial rotation in the frontal plane. SignificanceFindings form this study showed centrally and laterally redistributed foot loadings and increased forefoot inter-segment flexibility with manipulation, which may be used as baseline to evaluate toe-manipulation interventions in foot disorders, specifically hallux valgus deformity.

Characteristics of the Foot Static Alignment and the Plantar Pressure Associated with Fifth Metatarsal Stress Fracture History in Male Soccer Players: a Case-Control Study

BackgroundThere is a large amount of information regarding risk factors for fifth metatarsal stress fractures; however, there are few studies involving large numbers of subjects.This study aimed to compare the static foot alignment and distribution of foot pressure of athletes with and without a history of fifth metatarsal stress fractures.MethodsThe study participants comprised 335 collegiate male soccer players. Twenty-nine with a history of fifth metatarsal stress fractures were in the fracture group and 306 were in the control group (with subgroups as follows: 30 in the fracture foot group and 28 in the non-fracture group). We measured the foot length, arch height, weight-bearing leg–heel alignment, non-weight-bearing leg–heel alignment, forefoot angle relative to the rearfoot, forefoot angle relative to the horizontal axis, and foot pressure.ResultsThe non-weight-bearing leg–heel alignment was significantly smaller and the forefoot angle relative to the rearfoot was significantly greater in the fracture foot group than in the control foot group (P = 0.049 and P = 0.038, respectively). With regard to plantar pressure, there were no significant differences among the groups.Midfield players had significantly higher rates of fifth metatarsal stress fracture in their histories, whereas defenders had significantly lower rates (chi-square = 13.2, P < 0.05). There were no significant differences in the frequency of fifth metatarsal stress fractures according to the type of foot (kicking foot vs. pivoting foot) or the severity of ankle sprain.ConclusionsPlaying the midfield position and having an everted rearfoot and inverted forefoot alignment were associated with fifth metatarsal stress fractures. This information may be helpful for preventing fifth metatarsal stress fracture recurrence. More detailed load evaluations and a prospective study are needed in the future.

Foot Postural Deviations in Female Kathak Dancers

Background: Kathak is a very complex dance form in which greater emphasis is laid on foot work thus putting substantial amount of stress over the feet. The purpose of this study was to investigate the foot postural deviations amongst the Kathak dancers.Methods: Screening of 40 Female Kathak Dancers was done for the study from Department of Dance, Punjabi University, Patiala on the basis of inclusion criteria. Subjects were assessed for Postural deviations via. Foot Posture Index, Medial Longitudinal Arch Angle, Navicular Drop, Rearfoot angle and Forefoot angle.Results: Percentile analysis of Foot Posture index scores suggested that a large population of kathak dancers (approx 92.5 %) have pronated feet. Most of the Kathak dancers showed increase in Rearfoot angle (approx. 90%), Forefoot angle (approx.75%) and Navicular drop (approx. 97%) and decrease in Medial Longitudinal Arch angle (approx. 95%). Analysis of Coefficient of Correlation suggested a significant positive relationship of Foot Posture Index scores with Rearfoot angle (r = 0.40, p= 0.0087), Navicular Drop (r = 0.62, p= < 0.0001) and Forefoot angle (r = 0.51, p=0.0007) and a significant negative correlation with Medial Longitudinal Arch angle (r = -0.42, p= 0.0059).Conclusion: From the observations, it can be concluded that with time kathak dancers start developing certain Postural Deviations at Foot which can lead to hyperpronation. These changes if not treated on time may lead to various degenerative changes in the Foot and Ankle thus leading to the instabilities and can also make them susceptible to foot and ankle injuries, shin pain, etc. Thus, the study recommends that the dancers should be educated and trained about the foot problems associated with kathak dance and their prevention.

Forefoot varus predicts subtalar hyperpronation in young people.

Subtalar joint hyperpronation is a foot misalignment that has been associated with several musculoskeletal injuries. Forefoot varus is thought to result in subtalar hyperpronation during weightbearing circumstances. However, few studies have aimed to verify whether there is a significant relationship between forefoot alignment and subtalar hyperpronation. Moreover, no study has attempted to verify whether forefoot varus can predict subtalar hyperpronation in young individuals. Therefore, the purpose of this study was to verify whether forefoot varus can predict subtalar hyperpronation, measured using the rearfoot eversion angle test, the navicular drop test, and the Foot Posture Index (FPI), in young people. Fifty-four healthy adolescents volunteered for this study (28 boys and 26 girls). A single examiner evaluated the forefoot angle, rearfoot angle, navicular drop, and FPI of each participant. Statistical analysis included the Pearson correlation test and a linear regression analysis to establish the relationship between the variables. These results showed a high positive correlation between forefoot varus and rearfoot angle (r = 0.86; P < .001), navicular drop (r = 0.76; P < .001), and FPI (r = 0.82; P < .001). Moreover, the forefoot varus variable was able to predict 74% of the variability in the rearfoot angle, 58% in the navicular drop, and 67% in the FPI (P < .001). These findings support previous assumptions that individuals with forefoot varus present subtalar hyperpronation. Clinicians should not overlook forefoot alignment when prescribing foot orthoses for treating patients with foot misalignments.

Forefoot angle at initial contact determines the amplitude of forefoot and rearfoot eversion during running

BackgroundClinically, foot structures are assessed intrinsically – relation of forefoot to rearfoot and rearfoot to leg. We have argued that, from a biomechanical perspective, the interaction of the foot with the ground may influence forces and torques that are propagated through the lower extremity. We proposed that a more appropriate measure is an extrinsic one that may predict the angle the foot makes with ground at contact. The purposes of this study were to determine if the proposed measure predicts contact angles of the forefoot and rearfoot and assess if the magnitude of those angles influences amplitude and duration of foot eversion during running. MethodsWith the individual in prone, extrinsic clinical forefoot and rearfoot angles were measured relative to the caudal edge of the examination table. Participants ran over ground while frontal plane forefoot and rearfoot contact angles, forefoot and rearfoot eversion amplitude and duration were measured. Participants were grouped twice, once based on forefoot contact inversion angle (moderate<median and large>median) and once based on rearfoot contact inversion angle (moderate<median and large>median). FindingsThe forefoot and rearfoot extrinsic clinical angles predicted, respectively, the forefoot and rearfoot angles at ground contact. Large forefoot contact angles were associated with greater amplitudes (but not durations) of forefoot and rearfoot eversion during stance. Rearfoot contact angles, however, were associated with neither amplitudes nor durations of forefoot and rearfoot eversion. InterpretationPossible mechanisms for the increased risk of running injuries associated with large forefoot angles are discussed.

Hind-mid-forefoot Deformity in Hallux Valgus Deformity in Rheumatoid Arthritis: Radiographic Evaluation Grouped by Existence of Dorsal Dislocation of Second Metatarsophalangeal Joint

Hallux valgus deformity combined with dorsal dislocation of the second metatarsophalangeal joint is frequently observed in rheumatoid arthritis cases. However, hallux valgus deformity without lesser toe dislocation is also seen in rheumatoid cases. Dislocated second toe cause the loss of the lateral support on the hallux, suggesting the importance to confirm the state of lesser toe MTP joint when assessing the risk of HV recurrence after surgery, and there may be some differences in the mechanical transmission between hind-mid and forefoot based on whether dorsal dislocation of the MTP joint in the lesser toe is present, although findings are unclear. This study examined the relationship between radiographic findings from the hind, mid, and forefoot and hallux valgus angle in rheumatoid arthritis cases grouped based on the presence or absence of dorsal dislocation of the second metatarsophalangeal joint. X-rays of 160 feet and ankles with rheumatoid arthritis were evaluated for the first metatarsophalangeal Larsen grade, existence of second metatarsophalangeal dorsal dislocation, hallux valgus angle, intermetatarsal angle between the first and second intermetatarsals, shape of the first metatarsal head, position of the sesamoid, the metatarsus primus varus angle, diastasis between the base of the first and second metatarsals, angle between long axis of the talus and short axis of the navicular, internal arch angle, tibio-calcaneal angle, and calcaneal lateral offset. Based on Pearson product-moment correlation coefficient test, involvement of hindfoot deformity should always be considered when assessing hallux valgus deformity in rheumatoid arthritis patients. Although mechanism of mechanical transmission through hindfoot to Lisfranc joint seems to be different by the presence or absence of dorsal dislocation of the second metatarsophalangeal joint, Lisfranc looseness also must be considered when assessing hallux valgus including the surgery to avoid the progression or recurrence in rheumatoid arthritis cases. Dorsal dislocation of the second metatarsophalangeal joint strongly influences the exacerbation of hallux valgus in rheumatoid arthritis cases. Thus, it is may be important to achieve adequate reduction of the second metatarsophalangeal joint dislocation and make a stable metatarsophalangeal joint to avoid recurrence of hallux valgus after forefoot surgery in rheumatoid arthritis.

Forefoot angle determines duration and amplitude of pronation during walking

The biomechanical mechanisms that link foot structure to injuries of the musculoskeletal system during gait are not well understood. This study had two parts. The purpose of part one was to determine the relation between clinical rearfoot and forefoot angles and foot angles as they make contact with the ground. The purpose of part two was to determine the effects of large vs. moderate values of both forefoot and rearfoot inversion angles at foot contact on foot kinematics. Clinical foot angle, the relationship between the foot and an axis extrinsically defined relative to the ground, was calculated from digital photographs taken in a prone position. During three speeds of over-ground walking, we measured frontal plane rearfoot and forefoot angle relative to the ground at foot contact, and the following stance phase kinematic measures: amplitude of rearfoot and forefoot eversion, duration of rearfoot and forefoot eversion, and duration between heel-off and onset of rearfoot and forefoot inversion. We found that the clinical forefoot angle predicted the forefoot angle at foot contact. Individuals with a large inversion forefoot angle at contact also had greater amplitude of forefoot eversion and everted longer during stance. We discuss the possible mechanisms for the increased risk of injury to the hip reported for individuals that have a large clinical forefoot angle in non-weight bearing. Equally important is the finding that rearfoot angle at contact did not predict the motions of the rearfoot or forefoot during stance.

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. Five subjects in each group were retested by both clinicians after 4–6 weeks. Both intra-clinician and inter-clinician repeatability were evaluated using static and dynamic measures. A plaster mold method was used to quantify variability arising from marker placement error. Dynamic variability was measured by examining trial differences from the same subjects when multiple clinicians carried out the data collection multiple times. For hindfoot and forefoot angles, static and dynamic variability in both groups was found to be less than 4° and 6° respectively. The mSHCG model strategy of minimal reliance on anatomical markers for dynamic measures and inherent flexibility enabled by separate anatomical and technical coordinate systems resulted in a model equally repeatable in typically developing and planovalgus populations.

A comparison between joint coordinate system and attitude vector for multi-segment foot kinematics

The joint angles of multi-segment foot models have been primarily described using two mathematical methods: the joint coordinate system and the attitude vector. This study aimed to determine whether the angles obtained through these two descriptors are comparable, and whether these descriptors have similar sensitivity to experimental errors. Six subjects walked eight times on an instrumented walkway while the joint angles among shank, hindfoot, medial forefoot, and lateral forefoot were measured. The angles obtained using both descriptors and their sensitivity to experimental errors were compared. There was no overall significant difference between the ranges of motion obtained using both descriptors. However, median differences of more than 6° were noticed for the medial-lateral forefoot joint. For all joints and rotation planes, both descriptors provided highly similar angle patterns (median correlation coefficient: R>0.90), except for the medial-lateral forefoot angle in the transverse plane (median R=0.77). The joint coordinate system was significantly more sensitive to anatomical landmarks misplacement errors. However, the absolute differences of sensitivity were small relative to the joints ranges of motion. In conclusion, the angles obtained using these two descriptors were not identical, but were similar for at least the shank-hindfoot and hindfoot-medial forefoot joints. Therefore, the angle comparison across descriptors is possible for these two joints. Comparison should be done more carefully for the medial-lateral forefoot joint. Moreover, despite different sensitivities to experimental errors, the effects of the experimental errors on the angles were small for both descriptors suggesting that both descriptors can be considered for multi-segment foot models.

Effect of Limiting Ankle-Dorsiflexion Range of Motion on Lower Extremity Kinematics and Muscle-Activation Patterns During a Squat

Limitations in gastrocnemius/soleus flexibility that restrict ankle dorsiflexion during dynamic tasks have been reported in individuals with patellofemoral pain (PFP) and are theorized to play a role in its development. To determine the effect of restricted ankle-dorsiflexion range of motion (ROM) on lower extremity kinematics and muscle activity (EMG) during a squat. The authors hypothesized that restricted ankle-dorsiflexion ROM would alter knee kinematics and lower extremity EMG during a squat. Cross-sectional. 30 healthy, recreationally active individuals without a history of lower extremity injury. Each participant performed 7 trials of a double-leg squat under 2 conditions: a no-wedge condition (NW) with the foot flat on the floor and a wedge condition (W) with a 12° forefoot angle to simulate reduced plantar-flexor flexibility. 3-dimensional hip and knee kinematics, medial knee displacement (MKD), and ankle-dorsiflexion angle. EMG of vastus medialis oblique (VMO), vastus lateralis (VL), lateral gastrocnemius (LG), and soleus (SOL). One-way repeated-measures ANOVAs were performed to determine differences between the W and NW conditions. Compared with the NW condition, the wedge produced decreased peak knee flexion (P < .001, effect size [ES] = 0.81) and knee-flexion excursion (P < .001, ES = 0.82) while producing increased peak ankle dorsiflexion (P = .006, ES = 0.31), ankle-dorsiflexion excursion (P < .001, ES = 0.31), peak knee-valgus angle (P = .02, ES = 0.21), and MKD (P < .001, ES = 2.92). During the W condition, VL (P = 0.002, ES = 0.33) and VMO (P = .049, ES = 0.20) activity decreased while soleus activity increased (P = .03, ES = 0.64) compared with the NW condition. No changes were seen in hip kinematics (P > .05). Altering ankle-dorsiflexion starting position during a double-leg squat resulted in increased knee valgus and MKD, as well as decreased quadriceps activation and increased soleus activation. These changes are similar to those seen in people with PFP.

Efecto de las técnicas de articulación y manipulación sobre los apoyos plantares en el antepié varo infantil

Aim To detect varus forefoot disorder, define the characteristics of plantar pressures and analyze the effect of articulation and manipulation osteopathic techniques to correct this disorder. Method A prospective controlled experimental study was carried out in two groups, a control group and a treatment group, with an analysis based on Student's t-test. Articulation and manipulation techniques were applied in 62 pupils between the ages of 6 and 12 years, diagnosed with varus forefoot, in order to correct the affected bone segments. The extent of the forefoot varus angle and the rearfoot valgus was measured using a goniometer. Plantar pressures were measured using a pedobarographic device. Results The reduction of the varus forefoot angle was statistically significant in the treatment group. The static evaluation revealed that no mark was registered on the plantar surface either from the midfoot or from the head of the first metatarsal bone. During gait analysis, the trajectory of the pressure center of the foot was linear. The vertical peak force of the forefoot was found on the head of the second and third metatarsal bones. Conclusions Goniometry is an effective method to detect disorders due to varus forefoot. The angle of inversion of the metatarsal heads is significantly reduced by the application of articulation and manipulative osteopathic techniques. The correction in the disorder is demonstrated by a more balanced plantar pressure in the foot whilst standing and walking.

Repeatability of the modified Oxford foot model during gait in healthy adults

BackgroundThe Oxford foot model (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). MethodsSeventeen healthy adults (age=25.1±4.8 years, height=1.75±0.10m, weight=74.0±12.4kg) were tested on a single visit, during which 1 examiner recorded 2 sessions. For each session, 10 walking trials were recorded using a 12-camera motion analysis system (Vicon, Oxford, UK). Markers were removed and re-applied between sessions. Dynamic hindfoot and forefoot angles were calculated both with and without referencing to neutral stance (assuming neutral stance angles are zero in all planes). Using the 10 trial average, intraclass correlation coefficients (ICC2,k) and standard errors of the measurement were calculated for each reference condition, anatomical plane, and joint (hindfoot, forefoot). ResultsReferencing to neutral stance resulted in good reliability (ICC≥0.83) and small error (≤2.45°) for hindfoot and forefoot angle in all planes. Without referencing to neutral stance, sagittal and transverse plane reliability were also good (ICC≥0.90) and error small (≤3.14°); however, frontal plane reliability was poor (ICC≤0.77), with large error (≥4.86°). DiscussionOur results show that overall the OFM is reliable during adult gait. Reliability for adults is higher than previously reported in children. Referencing joint angles to neutral stance decreased error by up to 2° from previous reports.

The Relationship Between Forefoot and Rearfoot Static Alignment in Pain-Free Individuals With Above-Average Forefoot Varus Angles

This study used a within-subjects correlational design to determine the relationship between forefoot varus angle and standing rearfoot angle among individuals with above-average forefoot varus angles. Clinicians have long theorized that forefoot position is related to the standing rearfoot angle and that both may be related to pronation during gait. More recently, data suggest that the association between static forefoot and rearfoot position may be limited to those individuals with forefoot varus angles larger or smaller than average. However, little data are available on the association between static forefoot and rearfoot angles among individuals with larger than average forefoot varus angles. Twenty-three healthy participants (mean age = 27.04 +/- 6.24 years) with at least 8 degrees of forefoot varus bilaterally were recruited for this study. Goniometric measurements of forefoot varus angle and standing rearfoot angle of each foot were taken. Intraclass correlation coefficients (ICCs) were used to assess intrarater and interrater reliability of the static forefoot and rearfoot angle measurements. The Pearson product moment coefficient was used to assess the association between the forefoot and rearfoot static angles. ICCs for intrarater and interrater reliability of the forefoot and rearfoot angles were equal to or greater than 0.98 and 0.92, respectively. Forefoot varus angle was significantly correlated with standing rearfoot angle (P = .034). Among healthy individuals with larger than average forefoot varus angles, static forefoot varus and standing rearfoot valgus angles demonstrate a positive association.

Acute effect of orthoses on foot orientation and perceived comfort in individuals with pes cavus during standing

Background Changes in foot orientation due to orthoses and the relationship with perceived comfort are still unclear in pes cavus. The purpose of this study was to determine the acute changes of fore-foot angles due to the use of custom-made orthoses and their relationship with perceived comfort during standing. Methods Two photographs were taken using a color-coded camera-based system from the posterior and medial views of 20 subjects with bilateral pes cavus under barefoot and with orthoses conditions during standing. Djian–Annonier, calcaneal inclination, 1st metatarsal declination and rearfoot angles were measured and perceived comfort in the forefoot, midfoot and rearfoot was estimated using an adapted Visual Analogue Scale-type questionnaire. Results In comparison with the barefoot condition, orthoses increased significantly the 1st metatarsal declination angle by 1.9° ( p < 0.01), and the Djian–Annonier angle by 1.1° ( p = 0.02). The calcaneal inclination angle decreased significantly by an average of 3.0° ( p < 0.01). Wearing orthoses significantly improved perceived comfort in forefoot, midfoot and rearfoot when compared to barefoot condition ( p < 0.01). A significant correlation was observed between variation of calcaneal inclination angle and the perceived comfort at the midfoot ( r = −0.44; p = 0.04). Conclusion Flattening of foot arch and improvement of midfoot perceived comfort in pes cavus could be attributed to the reduction of the calcaneal inclination angle in the sagittal plane by using orthoses during standing.

The Relationship Between Forefoot, Midfoot, and Rearfoot Static Alignment in Pain-Free Individuals

Correlational study. To determine whether, and to what degree, a relationship exists between forefoot angle and weight-bearing midfoot and rearfoot position. There have been conflicting reports with regard to the degree to which the structure of the foot may influence the function. The influence of forefoot structure on weight-bearing midfoot and rearfoot position has not been extensively investigated. Fifty-one healthy subjects participated in this study (26 male and 25 female). Forefoot angle was measured in prone as varus (positive numbers), neutral (0), or valgus (negative numbers). Navicular drop was measured from subtalar joint neutral to unilateral standing relaxed. Rearfoot angle was measured in relaxed single-limb stance as the angle between a line that bisected the calcaneus and a line that bisected the lower third of the leg. The relationships between forefoot angle and navicular drop, and between forefoot angle and relaxed rearfoot angle, were investigated. The same relationships were also investigated in the neutral forefoot subgroup when the sample was divided in 3 subgroups based on 1 standard deviation of forefoot angle. There is a significant relationship between forefoot angle and relaxed rearfoot angle (r = 0.52, P < .001), as well as between forefoot angle and navicular drop (r = 0.55, P < .001), in the whole sample (n = 51). Average degrees of forefoot angle in the neutral subgroup (between 1.0 degree and 8 degrees of varus) are not associated with predictable positions of relaxed rearfoot angle (r = 0.19, P = .24) or navicular drop (r = 0.01, P = .96). Based on the results of this study, there is a significant relationship between forefoot angle and relaxed rearfoot angle, as well as between forefoot angle and navicular drop, in healthy subjects. These relationships were not found when forefoot varus values were within a standard deviation of the sample mean.

Comparison between Manual and Computer-Assisted Measurements of Hallux Valgus Parameters

The aim of this study was to determine if there are intraobserver and interobserver differences in reliability when measuring hallux valgus angles (HVA), 1-2 intermetatarsal angles (IMA), and distal metatarsal articular angles (DMAA) manually compared to computer-assisted means. Our hypothesis was that the measurements taken by computer-assisted methods of these three forefoot angles would be superior in consistency and accuracy compared to manual measurements. Four examiners studied 20 weightbearing anteroposterior radiographs of patients with hallux valgus. Manual measurements were taken on photographic prints using a goniometer and a fine point pen. Computer-assisted measurements were taken on digitized images using computer software. Three sets of measurements by both of these methods were taken 1 week apart. There was no statistically significant difference between digital and manual measurements for any of the three angles measured (p .05). However, the reliability of measurements within a range of 5 degrees for both methods was 70.6% for HVA, 84% for 1-2 IMA, and 59% for DMAA. There were no significant differences in interobserver and intraobserver reliability in measuring 1-2 IMA and HVA, regardless of the method of measurement; however, there was a significant difference in interobserver reliability when measuring the DMAA either on computer or manually (p = <.05).