Pes Cavus Foot Research Articles

Assessment of biomechanical parameters of feet in patients with multiple sclerosis during walking

Rationale. Walking and balance disorders, modi fi ed foot muscles kinematics and walking stereotypes are typical for the patients with Multiple Sclerosis (MS).Objective. To assess the biomechanical parameters of the feet in MS patients with diff erent neurological status during walking.Material and methods. Data analysis of 102 patients with relapsing-remitting MS was carried out for two groups depending on the value of the Expanded Disability Status Scale (EDSS). Plantar pressure distribution was measured on with the pedographic platform emed, novel gmbh, Munich, Germany, using a “fi rst step” protocol.Results and conclusion. Loading of the heel, the area of central metatarsal heads is decreased and loading of the toes is increased during walking in MS patients. Diff erences were found for the spreading coeffi cient (the ratio of the width to the length of the foot), the dynamic width of the foot in patients with an EDSS ≥ 4 is signi fi cantly less in the instep, in the middle and in the narrowest parts of the foot, which leads to the decrease of the contact area. It has been shown that patients with MS who are mobile or walk without assistance are more likely to have pes cavus foot compared to MS patients with minor impairments. The load of the medial side of the foot is greater than the lateral side, which indicates the predominance of the valgus foot. The pronation-supination index is signi fi cantly higher in the patients with moderate impairments in toe-off phase. Evaluation of foot deformity based on the measurement of biomechanical parameters of plantar pressure distribution makes it possible to plan the treatment and rehabilitation tactics in MS patients.

Evaluation of the type of plantar footprint in a public institution in Cuenca

To identify the type of plantar footprint in adolescents between 10 and 15 years of age in a public institution in Cuenca. Methods: The study was quantitative, descriptive and cross-sectional. The type of plantar footprint was determined by means of a photo-podoscope. Data were tabulated using Excel and SPSS 22.0. The population was selected by non-probabilistic sampling, evaluating 75 students who met the inclusion and exclusion criteria. Results: Within the population studied a higher percentage of pes cavus was found with 56% in the right foot and 45.3% in the left foot. In the right foot there was a higher percentage of pes cavus in women (61.9%) than in men (38.1%); in the left foot, the normal/cavus foot predominated in men (90%) and in women the pes cavus foot (76.5%). In the relationship between plantar footprint and age, in the right foot there was 23.8% of pes cavus at the age of 10 years and in the left foot 29.4% at the age of 12 years. Finally, in relation to plantar footprint and Body Mass Index (BMI), in the right foot 73.7% of pes cavus was observed in normal weight and in the left foot 67.6%. Conclusions: The predominant plantar footprint type in the students evaluated was pes cavus.

Is Morton's neuroma in a pes planus or pes cavus foot lead to differences in pressure distribution and gait parameters?

Morton's neuroma (MN) is a compressive neuropathy of the common digital plantar nerve causing forefoot pain. Foot posture and altered plantar pressure distribution have been identified as predispoing factors, however no studies have compared individuls with different foot postures with MN. Thus, we aimed to compare the effect of MN on spatiotemporal gait parameters and foot-pressure distribution in individuals with pes planus and pes cavus. Thirty-eight patients with unilateral MN were evaluated between June and August 2021. Nineteen patients with bilateral pes planus and 19 age and gender-matched patients with pes cavus who had no prior surgery were recruited. A Zebris FDM–THM–S treadmill system (Zebris Medical GmbH, Germany) was used to evaluate step length, stride length, step width, step time, stride time, cadence, velocity, foot-pressure distribution, force and whole stance phase, loading response, mid stance, pre-swing and swing phase percentages. There were no significant differences between the groups in spatiotemporal gait parameters (p > 0.05). Patients with pes planus displayed the following results for step length (49.36 ± 8.38), step width (9.05 ± 2.12), stance phase percentage (65.92 ± 2.11), swing phase percentage (34.08 ± 2.12), gait speed (2.96 ± 0.55), and cadence (100.57 ± 8.84). In contrast, patients with pes cavus displayed the following results for step length (49.06 ± 8.37), step width (8.10 ± 2.46), stance phase percentage (64.96 ± 1.61), swing phase percentage (34.79 ± 1.60), gait speed (2.95 ± 0.65), and cadence (99.73 ± 13.81). Foot-pressure distribution values showed no differences were detected in force, forefoot, and rearfoot pressure distribution, except for midfoot force (p < 0.05). The forefoot, midfoot, and rearfoot pressure values for the pronated group were 32.14 ± 10.90, 13.80 ± 3.03, and 22.78 ± 5.10, and for the supinated group were 33.50 ± 11.49, 14.23 ± 3.11 and 24.93 ± 6.52. MN does not significantly affect spatiotemporal gait parameters or foot-pressure distribution in patients with pes cavus or pes planus.

NGS-Panel Diagnosis Developed for the Differential Diagnosis of Idiopathic Toe Walking and Its Application for the Investigation of Possible Genetic Causes for the Gait Anomaly.

Idiopathic toe walking (ITW) describes a condition affecting approximately 4.5% of children. Toe walking is an accompanying symptom for many hereditary disorders. This retrospective study uses next-generation sequencing-panel-diagnosis to investigate the feasibility of genetic testing to research the possible genetic causes of ITW and for differential diagnosis. Data were taken from our inhouse database, the minimum age for participants was 3 years. Underlying neurological or orthopaedic conditions were tested for and ruled out prior to diagnosing ITW. Patients, who experienced complications before, during or immediately after birth, children with autism, and patients toe walking less than 50% of the time were excluded. Eighty-nine patients were included in the study, in which 66 (74.2%) patients were boys and 23 (25.8%) girls. Mean age at testing was 7.7 years (range: 3-17 years). Fifteen of the 89 patients included in the study (16.9%) had a genetic variant identified as likely pathogenic or pathogenic by the genetics laboratory. Additionally, we found 129 variants of uncertain significance. About 65.2% of patients showed a pes cavus foot deformity, 27% of patients reportedly had at least one relative who also displayed the gait anomaly, and 37.1% had problems with their speech development. Despite the limitations of the sample size and the scope of our genetic testing targets, our results indicate that research into the genetic causes of ITW could better our understanding of the causes of ITW in otherwise healthy children, to help develop novel methods to detect serious conditions early. ITW could be an early onset symptom for further hereditary conditions.

Issue Information

A Pakistani family with Ehlers–Danlos musculocontractural type 2 disease. (a) Pedigree showing autosomal recessive mode of inheritance for the disease phenotype (b) Protein models with wild and mutated amino acids. (c) (A–E) Distinctive facial features; (F–H) Hands and fingers; (KO) Long toes and bilateral pes cavus feet. Further details can be seen in the article by Ullah et al. in this issue. image

Multiple cranial nerve enlargement in Charcot-Marie-Tooth disease

Hypertrophy of peripheral nerves are commonly reported in patients with demyelinating forms of Charcot-Marie-Tooth disease (CMT).1 Herein, an under-recognised association with hypertrophy of multiple cranial nerves in a patient with...

A histological study on the tendons at chiasma plantare in pes cavus

In the dysfunction of large muscles of the leg, tendon transfer surgery is found to be very helpful in restoring the normal function of these muscles. The tendons involved in the chiasma plantare play a major role in this regard. The present cadaveric study has been carried out in cadavers presenting pes cavus. Cadaveric feet presenting pes cavus were identified based on their foot prints. All these tendons and their interconnections were subjected to histological procedures. The sections of the tendons were stained with hematoxylin and eosin in order to identify the underlying pathologies in the tendons. Various types of tendinous interconnections between the tendons of flexor digitorum longus and flexor hallucis longus were noted. The histological findings showed infiltration of lymphocytes in the tendon sheath indicating tenosynovitis and tendinitis. This could be attributed to the compression of the tendons. A few tendons were also stretched due to the skeletal framework of the foot in pes cavus. The bones along the medial longitudinal arch in pes cavus feet could tend to develop spurs or elongated tuberosity that could impinge on the tendons causing the tendons to stretch and elongate. In harvesting the tendons for grafting, the surgeons must be aware about the pathologies involved, such as tendinitis or tenosynovitis, in order to reduce the time taken for the healing of the graft post-surgery. These variations and histological findings can sub-serve as an efficient guide for the restoration of non-functioning muscles of the lower limb.

Progression of Charcot-Marie-Tooth Foot Deformities in a Family With CMT1A

We present an image illustrating the progression of pes cavus foot deformities over three generations in a family with CMT1A.

A Rare Case of Charcot-Marie-Tooth Disease Type 1C With an Unusual Presentation

Charcot-Marie-Tooth neuropathy type 1 (CMT1) is an inherited demyelinating neuropathy characterized by distal muscle weakness and atrophy. Charcot-Marie-Tooth disease type 1C (CMT1C) is a rare form of CMT1 caused by mutations in the lipopolysaccharide-induced tumor necrosis factor (LITAF) or small integral membrane protein of the lysosome/late endosome (SIMPLE) gene. Phenotypically, CMT1C is characterized by sensory loss and slow conduction velocity, and is typically slowly progressive and often associated with pes cavus foot deformity and bilateral foot drop. A 42-year-old female presented with a 10-year history of slowly progressive bilateral calf pain and cramps. After multiple electromyography/nerve conduction studies (EMG/NCS) and genetic testing, the patient was revealed to have CMT1C with a heterozygous pathogenic variant, c.334G>A (p.Gly112Ser). However, the presentation of the patient's CMT1C phenotype was unusual compared to patients with similar diagnosis in a previous study, including a normal sensory exam with the exception of high arches and mildly reduced vibratory sense. Additionally, the patient's teenage son already started showing symptoms of CMT1C despite the fact that the onset of the disease typically occurs at an older age. This particular case further highlights the idea that the phenotype related to CMT1C may have a wide spectrum of disease severity.

Is Fibular Sesamoidectomy a Viable Option for Sesamoiditis? A Retrospective Study

Category:Midfoot/ForefootIntroduction/Purpose:Although the first metatarsophalangeal joint sesamoids have biomechanical value in the foot, pathologic conditions of these sesamoids are a source of disabling pain for patients, particularly during toe-off. Underlying causes include acute fracture, acute separation of bipartite sesamoids, sesamoiditis caused by repetitive trauma, infection, chondromalacia, osteochondritis dissecans, and osteoarthritis. Nonoperative treatment is the initial standard of care and has satisfactory outcomes overall, but operative management may be indicated in cases of pain refractory to conservative management. Surgical management includes tendo-Achilles or gastrocnemius lengthening, dorsiflexion osteotomy at the base of first metatarsal, corrective osteotomies, fusions for fixed pes cavus foot. Sesamoidectomy is a relatively uncommon procedure but should be considered if 6- 12 months of conservative managements fail or if the patient experiences ongoing debilitating symptoms.Methods:A retrospective chart review was conducted at our institution from 2009-2018. Twelve patients diagnosed with fibular sesamoiditis were treated with sesamoidectomy. Baseline patient demographics as well as postoperative outcomes were recorded. All patients were initially treated for an extended period conservatively with orthotics, anti-inflammatory medications, physical therapy, limitation of activity and a trial of non-weight bearing. Despite these measures, symptoms persisted for these twelve patients - all of who then underwent fibular sesamoidectomy for their symptoms. The fibular sesamoidectomy was performed by one of the three fellowship trained foot and ankle surgeons. All surgeons used plantar approach with a longitudinal incision on the lateral edge of the first metatarsal fat pad. Postoperatively, patients were kept non–weight bearing for 2 weeks and in a post-op walking shoe for 6 weeks.Results:Average age of the patients was 38 years. Ten of twelve patients (83%) were female. Majority of the patients (10) had no history of trauma, only two referred forefoot injury in the past. Average follow-up was 35 months.Two patients had both hallux valgus and hallux rigidus. One had preexisting rheumatoid arthritis with involvement of the first MTP. MRI showed 5 of 12 (42%) of patients had avascular necrosis of the sesamoid based on magnetic resonance imaging. None of the patients developed cock-up deformity of the lesser toes or hallux varus deformity, clinically or radiologically. Two patients experienced transient neuritis, one developed a superficial infection, and one had painful postoperative scarring. Hallux varus deformity was not observed in any patients. None underwent reoperation.Conclusion:Our study contradicts earlier studies which associate sesamoidectomy with high incidence of complications, particularly hallux varus. But, most of these earlier reports focus on combinations of medial, lateral, and paired excision, rather than lateral excision alone, unlike our study.Hence, fibular sesamoidectomy can be a safe, viable procedure for patients who fail conservative measures for sesamoiditis. The plantar lateral approach allows for adequate exposure of the fibular sesamoid, repair of the plantar plate, and preservation of flexor hallucis brevis, and is beneficial in preventing the occurrence of hallux varus deformity.

Is Pes Cavus Alignment Associated With Lisfranc Injuries of the Foot?

Lisfranc (tarsometatarsal joint) injuries are relatively rare, accounting for less than 1% of all fractures, and as many as 20% of subtle Lisfranc injuries are missed at the initial patient presentation. An undiagnosed Lisfranc injury can have devastating consequences to the patient. Therefore, any factor that can raise a clinician's index of suspicion to make this diagnosis is potentially important. The cavus foot has been associated with various maladies of the lower extremity, but to our knowledge, it has not been reported to be associated with Lisfranc injury. Do patients who experience a low-energy Lisfranc injury have greater talar head coverage and a greater talo-first metatarsal angle than control subjects? A retrospective, case-control study was conducted from September 2011 to December 2014 to identify patients diagnosed and treated for a low-energy Lisfranc injury. Twenty-three adult patients with an average age of 42.6 years (SD, 16.3 years) were identified and compared with 61 adult control subjects with an average age of 49.4 years (SD, 14.1 years). Control subjects came from the practice of a fellowship-trained foot and ankle orthopaedic surgeon. Control subjects underwent a history and physical, clinical examination, and diagnostic imaging to confirm that they had no prior foot disorder, no prior foot surgeries, were within 3 years of age of a patient with a Lisfranc injury, and were independent ambulators. Two authors (DSD and JDP) measured the talonavicular and talo-first metatarsal angles on weightbearing AP and lateral radiographs of the foot. The intrarater reliability and interrater reliability for the talo-first metatarsal angle and the talonavicular angle showed high agreement. The intrarater intraclass correlation coefficients (ICC) of the talo-first metatarsal angle were 0.94 (95% CI, 0.91-0.96) and 0.93 (95% CI, 0.9-0.96). For the talonavicular angle the ICCs were 0.83 (95% CI, 0.75-0.89) and 0.88 (95% CI, 0.81-0.92) for Raters 1 and 2 respectively. The interrater ICCs were 0.91 (95% CI, 0.69-0.96) for the talo-first metatarsal angle and 0.9 (95% CI, 0.85-0.94) for the talonavicular angle. The patients and controls were compared to determine if the patients who sustained a Lisfranc injury were more likely to have a pes cavus foot alignment. We performed a mixed modeling analysis to control for potential cofounding variables and determine if there was an association of Lisfranc injury with the talo-first metatarsal angle and the talonavicular angle. After controlling for confounding variables such as the effect of the measurement round effect and the effect of the rater, our repeated measures analysis via mixed model showed patients were associated with a higher talo-first metatarsal angle than control subjects (adjusted least square mean for patients = 3.05; for controls = -2.65; mean difference, 5.7; p = 0.001). Repeated measures analysis via mixed model showed that patients also were associated with a more positive talonavicular angle than control subjects (adjusted least square mean for patients = -4.83, for controls = -11; mean difference, 6.17; p = 0.002). Patients with Lisfranc injuries had a higher mean talo-first metatarsal angle than did control subjects (1.9° ± 7.9° versus -2.2° ± 7.3°; mean difference, 4.1°; 95% CI, -7.7° to -0.5°; p = 0.028), and less talar uncovering (-4.2° ± 9.7° versus -11° ± 8°; mean difference, 6.7°; 95% CI, -6.7° to -10.8°; p = 0.001). We found that cavus midfoot alignment was more prevalent among patients with Lisfranc injuries than among individuals with no foot injury or disorder. Although this does not suggest that cavus alignment causes or predisposes patients to this injury, we believe the finding is important because this provides a radiographic parameter that clinicians can use to raise their index of suspicion for a Lisfranc injury and aggressively pursue this diagnosis. Future studies would benefit from obtaining contralateral foot imaging at the time of injury in all patients with Lisfranc injury or prospectively following patients with foot imaging and recording the incidence of future foot injury. Level III, prognostic study.

Medial Longitudinal Arch Angle Presents Significant Differences Between Foot Types: A Biplane Fluoroscopy Study.

The structure of the medial longitudinal arch (MLA) affects the foot's overall function and its ability to dissipate plantar pressure forces. Previous research on the MLA includes measuring the calcaneal-first metatarsal angle using a static sagittal plane radiograph, a dynamic height-to-length ratio using marker clusters with a multisegment foot model, and a contained angle using single point markers with a multisegment foot model. The objective of this study was to use biplane fluoroscopy to measure a contained MLA angle between foot types: pes planus (low arch), pes cavus (high arch), and normal arch. Fifteen participants completed the study, five from each foot type. Markerless fluoroscopic radiostereometric analysis (fRSA) was used with a three-dimensional model of the foot bones and manually matching those bones to a pair of two-dimensional radiographic images during midstance of gait. Statistically significant differences were found between barefoot arch angles of the normal and pes cavus foot types (p = 0.036), as well as between the pes cavus and pes planus foot types (p = 0.004). Dynamic walking also resulted in a statistically significant finding compared to the static standing trials (p = 0.014). These results support the classification of individuals following a physical assessment by a foot specialist for those with pes cavus and planus foot types. The differences between static and dynamic kinematic measurements were also supported using this novel method.

Comparison of Static and Dynamic Balance of Physically Active College Women with Different Foot Arch Heights

Introduction: Balance is one of the pivotal and inseparable components in daily activities and sports performance. Better and more comprehensive recognize of effective factors on quality of balance and how they impress, provide the opportunity which helps to improve motor-base factors in whole life and avoids negative impacts. It seems that anatomical abnormalities such as flat and pescavus foot and morphologic features of the foot can affect motor fitness characteristics like balance. So, this research aimed to compare the static and dynamic balance of women college athletes which have different foot arch heights. Materials and Methods: Static and dynamic balance were assessed in 90 women athletes in three types of foot arch: flat foot (30 persons), pescavus foot (30 persons) and normal foot (30 persons); it was done using stabilometer device with open-eye participant and maintaining a single leg stance (a measure of static balance), while dynamic balance was tested with putting a dominant step on a device (a measure of dynamic balance). Besides, to differentiate between flat, pescavus and normal foot arch, the navicular drop was tested with Brady attributive method. To test and analyze statistical datum, also one-way ANOVA statistical method was used via SPSS 19 software. Results: There was a significant difference in total area of the swing movement (P = 0.002) in static balance; however, there is not any significant difference between the study groups in dynamic balance (P = 0.098). Conclusion: Although static balance in person who suffers from flat and pescavus foot arch abnormality is lower than normal foot arch, but in dynamic balance, no significant differences between the three groups of foot arch height were noticed. So, the people who suffers from flat and pescavus foot arch should do their daily activities with more accuracy and attention.

Effects of custom-made insoles on idiopathic pes cavus foot during walking

From a subject group of pes cavus, the purpose of this study was to evaluate the biomechanical characteristics of lower limbs, based on plantar foot pressure and electromyography (EMG) activities, by the effects on two kind of custom-made insoles. Ten individuals among thirty females with a clinical diagnosis of idiopathic pes cavus (mean age (SD): 22.3 (0.08) years) were selected for the study. The plantar foot pressure data and EMG activities of four lower limb muscles were collected, when subjects walked on a treadmill, under three different experimental conditions. The plantar foot pressure data was analyzed, after the bilateral foot was divided into three areas of masks and into four sections of stance phase, to compare plantar foot pressure. The EMG activities were analyzed for integrated EMG (IEMG) value. The results show that plantar foot pressure concentrated in particular parts is decreased by custom-made insoles. In the case of EMG, all the muscle activities decreased significantly. The custom-made insoles dispersed pressure concentrated by the higher medial longitudinal arch and improved the efficient use of muscles. In particular, the extension structure in the forefoot of custom-made insoles was more efficient for pes cavus. Therefore, it could help patients to walk, by offering support to prevent the disease of pes cavus deformity, and to relieve the burden and fatigue in the lower limbs on gait.

Foot posture is associated with kinematics of the foot during gait: A comparison of normal, planus and cavus feet

Variations in foot posture are associated with the development of some lower limb injuries. However, the mechanisms underlying this relationship are unclear. The objective of this study was to compare foot kinematics between normal, pes cavus and pes planus foot posture groups using a multi-segment foot model. Ninety-seven healthy adults, aged 18–47 were classified as either normal (n=37), pes cavus (n=30) or pes planus (n=30) based on normative data for the Foot Posture Index, Arch Index and normalised navicular height. A five segment foot model was used to measure tri-planar motion of the rearfoot, midfoot, medial forefoot, lateral forefoot and hallux during barefoot walking at a self-selected speed. Angle at heel contact, peak angle, time to peak angle and range of motion was measured for each segment. One way ANOVAs with post-hoc analyses of mean differences were used to compare foot posture groups. The pes cavus group demonstrated a distinctive pattern of motion compared to the normal and pes planus foot posture groups. Effect sizes of significant mean differences were large and comparable to similar studies. Three key differences in overall foot function were observed between the groups: (i) altered frontal and transverse plane angles of the rearfoot in the pes cavus foot; (ii) Less midfoot motion in the pes cavus foot during initial contact and midstance; and (iii) reduced midfoot frontal plane ROM in the pes planus foot during pre-swing. These findings indicate that foot posture does influence motion of the foot.

G.P.37: Clinical overlap between centronuclear myopathy and axonal neuropathy (CMT2) due to mutation in DNM2 gene

Mutations in the DNM2 (dynamin 2) gene can cause centronuclear myopathy (CNM) or Charcot Marie Tooth (CMT) type 2 hereditary neuropathy. This is the first case report to our knowledge of a single patient affected by both CMT and CNM equally. We present a 20 year old lady with normal pre and perinatal history and no family history of muscle disease. She had reduced muscle tone from birth but motor and mental development was normal. She developed abnormal gait at 5 years old, with frequent trips and falls. Objectively there was a high arched palate, mild generalized muscle weakness (4/5 MRC) together with pes cavus foot deformities. At 12 years old incomplete opthalmoparesis and mild facial weakness was noticed. At that time, surgical correction of foot abnormalities was performed. The muscle weakness was slowly progressive. At 19 years old she had atrophy of distal muscles in upper and lower limbs with reduced fine motor skills – she was not able to open a bottle or unlock the door; and had waddling and tripping gait. CK level was normal. FVC was reduced (54%), with no need of nocturnal ventilation support. Cardiac examination was normal. Her EMG and NCV studies repeatedly showed typical pattern of pure motor primary axonal neuropathy. Consequently she was classified as having hereditary motor neuropathy plus and muscle biopsy was never performed. SMN1, HSP22, SH3TC2, HSP27, MFN2, BSCL2, GDAP1 genes were Sanger sequenced with no causal mutation identified. Finally whole exome sequencing was performed. After the detailed research, a heterozygous variant p.E368K (c.1102G>A) in DNM2 gene was identified and confirmed by Sanger sequencing. This mutation was already reported to be pathogenic in CNM patients. The mutation arose de-novo. Our case report shows clear clinical overlap between axonal CMT and CNM and shows the variability of the phenotype, as this mutation is usually not associated with CMT. Mutations in the DNM2 (dynamin 2) gene can cause centronuclear myopathy (CNM) or Charcot Marie Tooth (CMT) type 2 hereditary neuropathy. This is the first case report to our knowledge of a single patient affected by both CMT and CNM equally. We present a 20 year old lady with normal pre and perinatal history and no family history of muscle disease. She had reduced muscle tone from birth but motor and mental development was normal. She developed abnormal gait at 5 years old, with frequent trips and falls. Objectively there was a high arched palate, mild generalized muscle weakness (4/5 MRC) together with pes cavus foot deformities. At 12 years old incomplete opthalmoparesis and mild facial weakness was noticed. At that time, surgical correction of foot abnormalities was performed. The muscle weakness was slowly progressive. At 19 years old she had atrophy of distal muscles in upper and lower limbs with reduced fine motor skills – she was not able to open a bottle or unlock the door; and had waddling and tripping gait. CK level was normal. FVC was reduced (54%), with no need of nocturnal ventilation support. Cardiac examination was normal. Her EMG and NCV studies repeatedly showed typical pattern of pure motor primary axonal neuropathy. Consequently she was classified as having hereditary motor neuropathy plus and muscle biopsy was never performed. SMN1, HSP22, SH3TC2, HSP27, MFN2, BSCL2, GDAP1 genes were Sanger sequenced with no causal mutation identified. Finally whole exome sequencing was performed. After the detailed research, a heterozygous variant p.E368K (c.1102G>A) in DNM2 gene was identified and confirmed by Sanger sequencing. This mutation was already reported to be pathogenic in CNM patients. The mutation arose de-novo. Our case report shows clear clinical overlap between axonal CMT and CNM and shows the variability of the phenotype, as this mutation is usually not associated with CMT.

Comparison of plantar pressures and contact area between normal and cavus foot

BackgroundIn pes cavus, the medial longitudinal arch elevation reduces the contact surface area and consequently increases the corresponding plantar pressure measurements. This poor distribution of loads may produce associated pathology and pain in this or other areas of the body. Normal reference values need to be established in order to determine which patterns are prone to pathology. ObjectivesTo compare the plantar pressures and weight-bearing surface in a population with pes cavus to a population with neutral feet. MethodThe sample comprised 68 adults, 34 with pes cavus and 34 with neutral feet. The Footscan USB Gait Clinical System® was used as a platform to measure the total contact area and plantar pressure under the forefoot, midfoot, hindfoot, each metatarsal head, and the overall metatarsal area. A statistical analysis of the data was performed using Student's t-test for independent samples. ResultsThe pes cavus subjects showed a significant reduction in their weight-bearing area [neutral feet: 165.04 (±20.68)cm2; pes cavus: 118.26 (±30.31)cm2; p<0.001] and significantly increased pressures under all zones of the forefoot except the fifth metatarsal [metatarsal pressure: in neutral feet 503,797 (±9.32)kPa; in pes cavus 656.12 (±22.39)kPa; p<0.001]. ConclusionsCompared to neutral feet, pes cavus feet show a reduction in total contact surface and the load under the first toe. A significant increase is present in the load under the metatarsal areas, but the relative distribution of this load is similar in both groups.

Racial differences in foot disorders and foot type

To describe racial differences in the frequency of structural foot disorders and pes planus and pes cavus foot types in a large cohort of African American and white men and women ages ≥50 years. Of 1,695 Johnston County Osteoarthritis Project participants evaluated for foot disorders/types in 2006-2010, 4 with lower extremity amputation were excluded, leaving 1,691 available for analyses (mean age 69 years, mean body mass index [BMI] 31.5 kg/m(2) , 68% women, 31% African American). The most common foot disorders/types were identified using a validated foot examination. Each foot disorder/type was compared by race using logistic regression, controlling for age, BMI, and sex. Effect modification between race (African American versus white) and age, BMI (categorized as ≥30 kg/m(2) [obese] or <30 kg/m(2) [nonobese]), sex, and education was examined. Hallux valgus (64%), hammer toes (35%), overlapping toes (34%), and pes planus (23%) were common. Compared to whites, African Americans were almost 3 times more likely to have pes planus and were nearly 5 times less likely to have Tailor's bunions or pes cavus. Among the nonobese, African Americans were more likely than whites to have hallux valgus (adjusted odds ratio [OR(adj) ] 2.01, 95% confidence interval [95% CI] 1.39-2.92), hammer toes (OR(adj) 2.64, 95% CI 1.88-3.70), and overlapping toes (OR(adj) 1.53, 95% CI 1.09-2.13). Foot disorders are common among adults ages ≥50 years and differ by race. Future research is needed to determine the etiology of foot problems, especially those with racial differences, in order to inform prevention approaches.

Symmetry of foot alignment and ankle flexibility in paediatric Charcot–Marie–Tooth disease

BackgroundCharcot–Marie–Tooth disease is the most common inherited nerve disorder and typically presents with pes cavus foot deformity and ankle equinus during childhood. Level in the variation of symmetry of musculoskeletal lower limb involvement across the clinical population is unknown, despite early reports describing gross asymmetry. MethodsWe measured foot alignment and ankle flexibility of the left and right limbs using accurate and reliable standardised paediatric outcome measures in 172 patients aged 3–20years with a variety of disease subtypes recruited from the United States, United Kingdom, Italy and Australia. FindingsWhile a large range of differences existed between left and right feet for a small proportion of children, there was no overall significant difference between limbs. InterpretationThere are two important implications of these findings. Children with Charcot–Marie–Tooth disease generally exhibit symmetrical foot alignment and ankle flexibility between limbs. As such, analysing one limb only for biomechanical-related research is appropriate and satisfies the independence requirements for statistical analysis. However, because there are large differences between feet for a small proportion of children, an individualised limb-focused approach to clinical care is required.

The influence of foot geometry on the calcaneal osteotomy angle based on two-dimensional static force analyses

BackgroundMalalignment of the hindfoot can be corrected with a calcaneal osteotomy (CO). A well-selected osteotomy angle in the sagittal plane will reduce the shear force in the osteotomy plane while walking. The purpose was to determine the presence of a relationship between the foot geometry and loading of the calcaneus, which influences the choice of the preferred CO angle.MethodsA static free body force analysis was made of the posterior calcaneal fragment in the second half of the stance phase to determine the main loads: the plantar apeunorosis (PA) and Achilles tendon (AT). The third load is on the osteotomy surface which should be oriented such that the shear component of the force is zero. The force direction of the PA and AT was measured on 58 MRIs of the foot, and the force ratio between both structures was taken from the literature. In addition the PA-to-AT force ratio was estimated for different foot geometries to identify the relationship.ResultsBased on the wish to minimize the shear force during walking, a mean CO angle was determined to be 33° (SD8) relative to the foot sole. In pes planus foot geometry, the angle should be higher than the mean. In pes cavus foot geometry, the angle should be smaller.ConclusionFoot geometry, in particular the relative foot heights is a determinant for the individual angle in performing the sliding calcaneal osteotomy. It is recommended to take into account the foot geometry (arch) when deciding on the CO angle for hindfoot correction.