Three-Dimensional Finite Element Analysis and Biomechanical Analysis of Midfoot von Mises Stress Levels in Flatfoot, Clubfoot, and Lisfranc Joint Injury.

BACKGROUND Midfoot deformity and injury can affect the internal pressure distribution of the foot. This study aimed to use 3D finite element and biomechanical analyses of midfoot von Mises stress levels in flatfoot, clubfoot, and Lisfranc joint injury. MATERIAL AND METHODS Normal feet, flatfeet, clubfeet (30 individuals each), and Lisfranc injuries (50 individuals) were reconstructed by CT, and 3D finite element models were established by ABAQUS. Spring element was used to simulate the plantar fascia and ligaments and set hyperelastic coefficients in encapsulated bone and ligaments. The stance phase was simulated by applying 350 N on the top of the talus. The von Mises stress of the feet and ankle was visualized and analyzed. RESULTS The von Mises stress on healthy feet was higher in the lateral metatarsal and ankle bones than in the medial metatarsal bone. Among the flatfoot group, the stress on the metatarsals, talus, and navicular bones was significantly increased compared with that on healthy feet. Among patients with clubfeet, stress was mainly concentrated on the talus, and stress on the lateral metatarsal and navicular bones was significantly lower. The von Mises stress on the fractured bone was decreased, and the stress on the bone adjacent to the fractured bone was higher in Lisfranc injury. During bone dislocation alone or fracture accompanied by dislocation, the von Mises stress of the dislocated bone tended to be constant or increased. CONCLUSIONS Prediction of von Mises stress distribution may be used clinically to evaluate the effects of deformity and injury on changes in structure and internal pressure distribution on the midfoot.

Lateral Column Lengthening for Flexible Flat Foot: Was It Short to Begin With?

BACKGROUND: Flexible flatfoot (FF) is a common foot deformity that can often consist of foot pain. Surgical treatment is designed to lengthen the lateral column. OBJECTIVES: To resolve whether radiographic standing feet measurements of normo-plantigrade feet and FF, symptomatic or not, differ and to determine whether the lateral column is shorter. METHODS: The study comprised 72 patients (127 feet) consecutive patients, 18 years of age and older, who were divided into three groups: normal feet (56), asymptomatic FF (29), and symptomatic FF (42). All patients had a standing anterior posterior (AP) and lateral radiographs. AP images were used for the measurement of the talocalcaneal angle, talar-1st metatarsal angle, and talonavicular coverage. Lateral X-rays were used to estimate the talocalcaneal angle, talar-1st metatarsal angle, calcaneal pitch, naviculocuboid overlap, and column ratio. RESULTS: All three of the AP radiograph measurements differed among groups, and higher values were measured in the symptomatic FF group. Post hoc analysis found that the talonavicular coverage and the talocalcaneal angles also differed between symptomatic and asymptomatic FF patients. While some lateral measurements differed within groups, only the lateral talar-1st metatarsal angle distinguished between asymptomatic and symptomatic patients. The lateral column length was not found to be shorter among FF patients, weather symptomatic or not. CONCLUSIONS: Only the talonavicular coverage, the AP talocalcaneal, and the lateral talar-1st metatarsal angles were found to differ between asymptomatic and symptomatic FF patients. The lateral column was not found to be shorter.

Analysis of factors influencing improvement of idiopathic flatfoot.

ABSTRACT: Idiopathic flatfoot is common in infants and children, and patients with this condition are frequently referred to pediatric orthopedic clinics. Flatfoot is a physiologic process, and that the arch of the foot elevates spontaneously in most children during the first decade of life. To achieve a consensus as the rate of spontaneous improvement of flatfoot, the present study aimed to estimate the rate of spontaneous improvement of flatfoot and to analyze correlating factors.We reviewed the records of patients examined between May 2013 and May 2019 so as to identify those factors associated with idiopathic flatfoot below 12 years of age. We included patients with who had been followed for >6 months, and those for whom ≥2 (anteroposterior and lateral) weight-bearing bilateral radiographs of the foot had been obtained. The progression rates of the anteroposterior (AP) talo-first metatarsal angle, talonavicular coverage angle, lateral talo-first metatarsal angle, and calcaneal pitch angle were adjusted by multiple factors using a linear mixed model, with sex, body mass index, and Achilles tendon contracture as the fixed effects and age and each subject as the random effects.We found that 4 of the radiographic measurements improved as patients grew older. The AP talo-first metatarsal angle, talonavicular coverage angle, and the lateral talo-first metatarsal angle decreased, while the calcaneal pitch angle increased. The AP talo-first metatarsal angle (P < .001), talonavicular coverage angle (P < .001), and lateral talo-first metatarsal angle (P < .001) improved significantly; however, the calcaneal pitch angle (P = .367) did not show any significant difference. In general, the flatfeet showed an improving trend; after analyzing the factors, no sex difference was observed (P = .117), while body mass index (P < .001) and Achilles tendon contracture (P < .001) showed a negative correlation.The study demonstrated that children's flatfeet spontaneously improved at the age of 12 years. It would be more beneficial if the clinician shows the predicted appearance of the foot at the completion of growth by calculating the radiographic indices and identifying the correlating factors in addition to explaining that flatfoot may gradually improve. This will prevent unnecessary medical expenses and the psychological adverse effects to the children caused by unnecessary treatment.

Influence of the medial longitudinal arch of the foot in adult women in ankle isokinetic performance: a cross-sectional study.

BACKGROUND: Maintenance of the medial longitudinal arch (MLA) of the foot is fundamental during functional tasks and disorders can lead to clinical alterations. Studies have demonstrated that deficits in ankle isokinetic performance can predispose an individual to lower limb injuries. OBJECTIVES: To evaluate the muscular performance of cavus, planus, and normal feet by means of torque/body mass and the isokinetic phases, to generate 3D surface map analysis, and to verify whether there is a relationship between MLA height and arch height flexibility with isokinetic performance. METHODS: The sample consisted of 105 healthy adult women, divided into three groups: normal, cavus, and planus. Assessment in concentric mode at 30, 60, and 90 °/s in the dorsiflexion and plantarflexion of the ankle joint were analyzed during the three isokinetic phases (acceleration, sustained velocity, and deceleration). The variables total range of motion, peak of torque (PT), and angle of PT were extracted within the sustained velocity. RESULTS: In dorsiflexion at 60 °/s, the phase where the velocicty is sustained (load range phase) was higher in the planus group (MeanDifference=10.9 %; ω2p = 0.06) when compared with the cavus group. Deficits in the peak torque/body mass in dorsiflexion at 60 °/s (cavus feet: MD=-3 N.m/kg; ω2p = 0.06; and planus feet: MD=-1.1 N.m/kg; ω2p = 0.06) were also observed as well as in the 3D surface maps, when compared with the normal group. The flexibility of MLA had a negative correlation of PT at 30 °/s in cavus group. The heigth of MLA had a postive correlation with the PT for the cavus and planus group ate 60 °/s. All other results did not show differences between the groups. CONCLUSIONS: The planus groups showed a better capacity of attain and sustained the velocity in dorsiflexion in relation the cavus group. The cavus and planus group had deficts in torque in relation the normal. The correlations were weak between the measures of MLA and PT. Thereby, in general the differences between foot types showed small effect in isokinetic muscle performance measures of the plantar and dorsi flexores. TRIAL REGISTRATION: Study design was approved by the IRB (#90238618.8.0000.5231).

Foot Posture and Plantar Loading With Ankle Bracing.

CONTEXT: Arch height is one important aspect of foot posture. An estimated 20% of the population has pes planus and 20% has pes cavus. These abnormal foot postures can alter lower extremity kinematics and plantar loading and contribute to injury risk. Ankle bracing is commonly used in sport to prevent these injuries, but no researchers have examined the effects of ankle bracing on plantar loading. OBJECTIVE: To evaluate the effects of ankle braces on plantar loading during athletic tasks. DESIGN: Cross-sectional study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 36 participants (11 men, 25 women; age = 23.1 ± 2.5 years, height = 1.72 ± 0.09 m, mass = 66.3 ± 14.7 kg) were recruited for this study. INTERVENTION(S): Participants completed walking, running, and cutting tasks in 3 bracing conditions: no brace, lace-up ankle-support brace, and semirigid brace. MAIN OUTCOME MEASURE(S): We analyzed the plantar-loading variables of contact area, maximum force, and force-time integral for 2 midfoot and 3 forefoot regions and assessed the displacement of the center of pressure. A 3 × 3 mixed-model repeated-measures analysis of variance was used to determine the effects of brace and foot type (α = .05). RESULTS: Foot type affected force measures in the middle (P range = .003-.047) and the medial side of the foot (P range = .004-.04) in all tasks. Brace type affected contact area in the medial midfoot during walking (P = .005) and cutting (P = .01) tasks, maximum force in the medial and lateral midfoot during all tasks (P < .001), and force-time integral in the medial midfoot during all tasks (P < .001). Portions of the center-of-pressure displacement were affected by brace wear in both the medial-lateral and anterior-posterior directions (P range = .001-.049). CONCLUSIONS: Ankle braces can be worn to redistribute plantar loading. Additional research should be done to evaluate their effectiveness in injury prevention.

The apex angle of the rocker sole affects the posture and gait stability of healthy individuals.

BACKGROUND: Rocker sole (RS) shoes have been linked to impaired postural control. However, which features of RS design affect balance is unclear. RESEARCH QUESTION: Which RS design features affect standing balance and gait stability? METHODS: This study utilized an intervention and cross-over design. Twenty healthy young adults (10 males and 10 females) participated in this study. Standing balance and gait stability were measured using a single force platform and three-dimensional motion analysis system, respectively. The experimental conditions included the control shoe and five RS shoes in the combination of apex position (%) and apex angle (degree) for RS50-95, RS60-95, RS70-95, RS60-70, and RS60-110. The main outcome measures were the area surrounding the maximal rectangular amplitude, mean path length, average displacement of the center of pressure along the lateral and anterior/posterior directions, and maximal center of pressure excursion as the standing balance and lateral margin of stability as the gait stability. Statistical analyses were conducted using a two-way split-plot analysis of variance with repeated measures (with RS design as the within-subject factor and sex as the between-subject factor) and the Bonferroni post hoc test (α = .05). RESULTS: Regarding the mean path length, RS60-70 was significantly longer than the control shoe, and it showed a significantly increased lateral margin of stability. Thus, RS60-70 was shown to affect standing balance, limit of stability, and gait stability of the frontal plane during gait. SIGNIFICANCE: These results suggest that the apex angle of the RS design feature affects standing balance and gait stability, and RS60-70 is detrimental to stability. Therefore, when RS with a small apex angle is prescribed, it is necessary to consider the patient's balance ability.

Musculoskeletal abnormalities in a large international cohort of boys with 49,XXXXY.

49,XXXXY is the rarest X and Y chromosomal variation, with an incidence of 1 in 80,000-100,000 live male births and has been associated with numerous musculoskeletal abnormalities. Data was collected from an international cohort of boys with 49,XXXXY over 10 years. Children were evaluated by a multidisciplinary team consisting of a pediatric orthopedist, a neurogeneticist, a neurodevelopmentalist, and two physical therapists. Increased rates of torticollis (32.4%), hamstring tightness (42%), radioulnar synostosis (67.6%), pes planus (65.2%), and other foot abnormalities (86.9%) were observed. Several anomalies increased with age, specifically hamstring tightness, kyphosis, and scoliosis. The elucidation of the orthopedic profile of this population is necessary in order to provide healthcare providers with current medical information. This research further supports the necessity for the comprehensive multidisciplinary treatment of boys with 49,XXXXY.

Clinical and Radiological Outcomes of Subtalar Kalix II Arthroereisis for a Symptomatic Pediatric Flexible Flatfoot.

Background. The purpose of this study is to evaluate functional and radiological outcomes of subtalar arthroereisis in the treatment of symptomatic pediatric flexible flatfeet. Methods. A total of 16 patients (26 feet) were treated with a Kalix II as subtalar motion blocker between 2009 and 2014. Calcaneal pitch (CP) and Meary's angle (MA) were measured on radiographs preoperatively, directly postoperatively, and at follow-up 47 ± 17 (range 19-79) months. Patient satisfaction surveys were used to assess functional outcome and patient satisfaction. Results. Surgery was performed mostly for pain, walking problems, or a combination of both at a mean age of 12.5 ± 1.5 (range 10-15) years. Symptoms were relieved in 62.5% of patients in the postoperative phase and increased to 68.75% at follow-up. A statistically significant increase in CP of 2.8° and decrease in MA of 14.0° was observed directly postoperatively, which persisted during the follow-up period irrespective of Kalix removal. Revision surgery was necessary in 6 cases (23%) because of arthroereisis migration. Conclusion. Subtalar Kalix II arthroereisis significantly reduced clinical symptoms and improved the CP and MA directly postoperatively, which persisted during follow-up, irrespective of Kalix removal. Therefore, subtalar arthroereisis is a considerable intervention to reduce symptoms in children with symptomatic flexible flatfeet.Levels of Evidence: Level IV: Case series.

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.

Effects of foot orthosis on ground reaction forces and perception during short sprints in flat-footed athletes.

Prefabricated foot orthosis (FO) is commonly worn for flat foot management. This study aimed to investigate the kinetic and perceptual effects of wearing prefabricated FO among flat-footed athletes during bouts of sprints. Twenty male sprint-based sports athletes who had flat foot bilaterally ran at three test speeds (5, 6, 7 m/s) under two conditions: prefabricated FO and sham FO. Ground reaction force (GRF) variables and subjective perceptions were recorded. Kinetic variability of GRF variables were computed to indicate step-to-step variance. Biomechanically, wearing prefabricated FOs increased vertical impact force (p =.005), loading rate (p =.001), and kinetic variability of peak propulsive force (p =.038) and loading rate (p =.019) during sprinting speeds across 5 to 7 m/s. Subjectively, prefabricated FO provided better arch support (p =.001) but resulted in reduced forefoot cushioning (p =.001), heel cushioning (p =.002), and overall comfort (p =.008).

Weight-bearing radiographs and cone-beam computed tomography examinations in adult acquired flatfoot deformity.

BACKGROUND: Optimal characterization of Adult acquired flatfoot deformity (AAFD) on two-dimensional radiograph can be challenging. Weightbearing Cone Beam CT (CBCT) may improve characterization of the three-dimensional (3D) structural details of such dynamic deformity. We compared and validated AAFD measurements between weightbearing radiograph and weightbearing CBCT images. METHODS: 20 patients (20 feet, right/left: 15/5, male/female: 12/8, mean age: 52.2) with clinical diagnosis of flexible AAFD were prospectively recruited and underwent weightbearing dorsoplantar (DP) and lateral radiograph as well as weightbearing CBCT. Two foot and ankle surgeons performed AAFD measurements at parasagittal and axial planes (lateral and DP radiographs, respectively). Intra- and Inter-observer reliabilities were calculated by Intraclass correlation (ICC) and Cohen's kappa. Mean values of weightbearing radiograph and weightbearing CBCT measurements were also compared. RESULTS: Except for medial-cuneiform-first-metatarsal-angle, adequate intra-observer reliability (range:0.61-0.96) was observed for weightbearing radiographic measurements. Moderate to very good interobserver reliability between weightbearing radiograph and weightbearing CBCT measurements were observed for the following measurements: Naviculocuneiform-angle (ICC:0.47), Medial-cuneiform-first-metatarsal-gapping (ICC:0.58), cuboid-to-floor-distance (ICC:0.68), calcaneal-inclination-angle(ICC:0.7), axial Talonavicular-coverage-angle(ICC:0.56), axial Talus-first-metatarsal-angle(ICC:0.62). Comparing weightbearing radiograph and weightbearing CBCT images, statistically significant differences in the mean values of parasagittal talus-first-metatarsal-angle, medial-cuneiform-first-metatarsal-angle, medial-cuneiform-to-floor-distance and navicular-to-floor-distance was observed (P < 0.05). CONCLUSION: Moderate to very good correlation was observed between certain weightbearing radiograph and weightbearing CBCT measurements, however, significant difference was observed between a number of AAFD measurements, which suggest that 2D radiographic evaluation could potentially underestimate the severity of AAFD, when compared to 3D weightbearing CT assessment.

Postural Stability and Muscle Activation Onset during Double- to Single-Leg Stance Transition in Flat-Footed Individuals.

The effects of foot posture on postural stability and on muscular activation pattern for postural control remain unclear. This study aimed to investigate postural stability and muscular activation onset during the transition task from double- to single-leg stance in individuals with different foot postures. Twenty-seven healthy men (age: 21.5 ± 1.5 years) were divided into 3 groups using the Foot Posture Index: neutral foot (n = 10); flatfoot (n = 8); and high-arched foot (n = 9). Center of pressure (COP) data and muscle activation onset times of the tibialis anterior, peroneus longus, gastrocnemius medialis, and soleus during the transition task with eyes closed were compared among groups using one-way analysis of variance and a post-hoc Tukey honestly significant difference test (p < 0.05) when the data were normally distributed and the Kruskal-Wallis test and a post-hoc Mann-Whitney U-test with Bonferroni correction (p < 0.0167) when the data were not normally distributed. The COP displacements in the mediolateral and anteroposterior directions and the resultant COP displacement during the first 3 s after a stability time point, as determined by sequential estimation during the single-leg stance phase, differed significantly among the three groups (p < 0.05). Post-hoc tests showed that the displacements were significantly greater in the flatfoot group than in the neutral and high-arched foot groups (p < 0.05), and the effect sizes for these results were large. No muscular activation onset times showed significant intergroup differences. Postural stability was significantly decreased only in the flatfoot group, while muscle activation onsets did not differ significantly by foot posture during the transition task. Decreased postural stability may be one mechanism underlying the link between flatfoot and risk of lower limb injury, and foot posture represents a potential confounder for measuring postural stability during the transition task.

[Etiology, pathogenesis, clinical features, diagnostics and conservative treatment of adult flatfoot]. / Ätiologie, Pathogenese, Klinik, Diagnostik und konservative Therapie des adulten erworbenen Plattfußes.

BACKGROUND: On average, one in six adults is affected by an acquired flatfoot. This foot deformity is characterized by its progression of stages and in 10% of cases causes complaints that require treatment. Untreated, the loss of walking ability may result in the final stage. Correct staging is crucial to being able to offer a specific course of therapy including a wide spectrum of conservative and operative treatments. MATERIAL AND METHODS: This review is based on pertinent publications retrieved from a selective search in PubMed and Medline and on the authors' clinical experience. DIAGNOSTICS: The loss of function of static (spring ligament complex) and dynamic (tibialis posterior tendon) stabilizers causes the characteristic deformity with loss of the medial arch, hind foot valgus and forefoot abduction. In the late stage, severe secondary osteoarthritis in upper and lower ankle joints occurs and impedes walking ability. The essential physical examination is supplemented by weight-bearing dorsoplantar and lateral radiographs, which provide further information about axial malalignment (Meary's angle, Kite's angle). The long axis hind foot view allows analysis of the hindfoot valgus. MRI provides further information about the integrity of the tibialis posterior tendon, spring ligament complex and cartilage damage. THERAPY: The therapy aims to reduce pain, regain function and avoid development of secondary osteoarthritis and degenerative tendon disorders. Progress of the deformity should be stopped. Therefore, the main aspects of the deformity-loss of medial arch, hindfoot valgus and forefoot abduction should be addressed and corrected. In the acute phase, tendovaginitis of the tibialis posterior tendon can be treated sufficiently by anti-inflammatory measures, relieving mechanical loads on the tendon and muscle and physiotherapy.

A valuable option: Clinical and radiological outcomes of braided suture tape system augmentation for spring ligament repair in flexible flatfoot.

BACKGROUND: The purpose of this study was to evaluate the clinical and radiological outcomes of the briaded suture tape system augmentation in the treatment of flexible flatfoot. METHODS: Patients who underwent suture tape system augmentation in addition to spring ligament repair and flexor digitorum longus (FDL) transfer were reviewed. Clinical and radiological outcomes were studied. The results were compared to a matched control group who underwent the conventional surgical treatment, which involved FDL transfer only or FDL transfer plus medial sliding calcaneal osteotomy. RESULTS: A total of 40 patients (11 males and 29 females) who underwent hindfoot reconstruction for flexible flatfoot (Johnson stage 2) were reviewed. There were 18 patients in the suture tape system group and 22 patients in the control group. In the suture tape system group, there was excellent improvement in patients' symptoms, AOFAS score (97.9 improved from 76.7) and significantly more number of patients with stable single leg stance. Radiographic parameters improved postoperatively too. CONCLUSIONS: This is the first clinical study which studied the outcome of suture tape system augmentation for spring ligament repair. Patients with suture tape system reconstruction showed more number of patients with single leg stance and better correction of forefoot abduction. It is a reasonable component of hindfoot reconstruction.

Toe walking in children with cerebral palsy: a possible functional role for the plantar flexors.

Equinus and toe walking are common locomotor disorders in children with cerebral palsy (CP) walking barefoot or with normal shoes. We hypothesized that, regardless of the type of footwear, the plantar flexors do not cause early equinus upon initial foot contact but decelerate ankle dorsiflexion during weight acceptance (WA). This latter action promoted by early flat-foot contact is hypothesized to be functional. Hence, we performed an instrumented gait analysis of 12 children with CP (Gross Motor Function Classification System class: I or II; mean age: 7.2 yr) and 11 age-matched typically developing children. The participants walked either barefoot, with unmodified footwear (4° positive-heel shoes), or with 10° negative-heel shoes (NHSs). In both groups, wearing NHSs was associated with greater ankle dorsiflexion upon initial foot contact, and greater tibialis anterior activity (but no difference in soleus activity) during the swing phase. However, the footwear condition did not influence the direction and amplitude of the first ankle movement during WA and the associated peak negative ankle power. Regardless of the footwear condition, the CP group displayed 1) early flattening of the foot and ample dorsiflexion (decelerated by the plantar flexors) during WA and 2) low tibialis anterior and soleus activities during the second half of the swing phase (contributing to passive equinus upon foot strike). In children with CP, the early action of plantar flexors (which typically decelerate the forward progression of the center of mass) may be a compensatory mechanism that contributes to the WA's role in controlling balance during gait.NEW & NOTEWORTHY Adaptation to walking in negative-heel shoes was similar in typically developing children and children with cerebral palsy: it featured ankle dorsiflexion upon initial contact, even though (in the latter group) the soleus was always spastic in a clinical examination. Hence, in children with cerebral palsy, the early deceleration of ankle dorsiflexion by the plantar flexors (promoted by early flattening of the foot, and regardless of the type of footwear) may have a functional role.

Comfort and Ground Reaction Forces in Flat-Footed Female Runners: Comparison of Low-Dye Taping versus Sham Taping.

The purpose of this study was to examine the effects of low-Dye tape on comfort and ground reaction forces (GRF) in flat-footed female runners. A randomized cross-over study was conducted on 15 flat-footed female recreational runners. Participants ran at three speeds (9, 10, 11 km/h) under two conditions: low-Dye and sham taping. Comfort level was assessed using a 150-mm visual analog scale. GRF data were collected using an instrumented treadmill. Stance time, peak forces, and loading rates were extracted. Low-Dye taping showed a lower comfort level (low-Dye, 63.8 (24.3) mm, sham 122.0 (16.0) mm, mean difference [95% confident intervals], -58.2 [68.2, 48.2] mm, p < 0.001). For all biomechanical variables, there was no interaction (taping condition a speed) effect or difference between taping conditions. As running speed increased, there was a decrease in stance time (p < 0.001) and increase in loading rate (p = 0.009), impact peak (p = 0.004), active peak (p < .001), breaking peak (p < 0.001), propulsive peak (p < 0.001), medial peak (p < 0.001), and lateral peak (p < 0.001). Compared with sham taping, application of low-Dye taping was less comfortable but did not alter running ground reaction forces among flat-footed female runners.

The arch support insoles show benefits to people with flatfoot on stance time, cadence, plantar pressure and contact area.

BACKGROUND: Pes planus (flatfoot) is a common deformity characterized by the midfoot arch collapses during walking. As the midfoot is responsible for shock absorption, persons with flatfoot experience increased risk of injuries such as thumb valgus, tendinitis, plantar fasciitis, metatarsal pain, knee pain, lower-back pain with prolonged uphill, downhill, and level walking, depriving them of the physical and mental health benefits of walking as an exercise. METHODS: Fifteen female college students with flatfoot were recruited. A wireless plantar-pressure system was used to measure the stance time, cadence, plantar pressure, and contact area. Parameters were compared between wearing flat and arch-support insoles using a two-way repeated measures ANOVA with on an incline, decline, and level surface, respectively. The significance level α was set to 0.05. The effect size (ES) was calculated as a measure of the practical relevance of the significance using Cohen's d. RESULTS: On the level surface, the stance time in the arch-support insole was significantly shorter than in the flat insole (p<0.05; ES = 0.48). The peak pressure of the big toe in the arch-support insole was significantly greater than in the flat insole on the uphill (p<0.05; ES = 0.53) and level surfaces (p<0.05; ES = 0.71). The peak pressure of the metatarsals 2-4 and the contact area of the midfoot in the arch-support insole were significantly greater than in the flat insole on all surfaces (all p< 0.05). CONCLUSIONS: These results imply that wearing an arch-support insole provides benefits in the shortened stance time and generation of propulsion force to the big toe while walking on uphill and level surfaces and to the metatarsals 2-4 while walking on the level surface. More evenly distributed contact areas across the midfoot may help absorb shock during uphill, downhill and level walking.

Classification and Nomenclature: Progressive Collapsing Foot Deformity.

RECOMMENDATION: The historical nomenclature for the adult acquired flatfoot deformity (AAFD) is confusing, at times called posterior tibial tendon dysfunction (PTTD), the adult flexible flatfoot deformity, posterior tibial tendon rupture, peritalar instability and peritalar subluxation (PTS), and progressive talipes equinovalgus. Many but not all of these deformities are associated with a rupture of the posterior tibial tendon (PTT), and some of these are associated with deformities either primarily or secondarily in the midfoot or ankle. There is similar inconsistency with the use of classification schemata for these deformities, and from the first introduced by Johnson and Strom (1989), and then modified by Myerson (1997), there have been many attempts to provide a more comprehensive classification system. However, although these newer more complete classification systems have addressed some of the anatomic variations of deformities encountered, none of the above have ever been validated. The proposed system better incorporates the most recent data and understanding of the condition and better allows for standardization of reporting. In light of this information, the consensus group proposes the adoption of the nomenclature "Progressive Collapsing Foot Deformity" (PCFD) and a new classification system aiming at summarizing recent data published on the subject and to standardize data reporting regarding this complex 3-dimensional deformity. LEVEL OF EVIDENCE: Level V, consensus, expert opinion. CONSENSUS STATEMENTS VOTED: CONSENSUS STATEMENT ONE: We will rename the condition to Progressive Collapsing Foot Deformity (PCFD), a complex 3-dimensional deformity with varying degrees of hindfoot valgus, forefoot abduction, and midfoot varus.Delegate vote: agree, 100% (9/9); disagree, 0%; abstain, 0%.(Unanimous, strongest consensus)CONSENSUS STATEMENT TWO: Our current classification systems are incomplete or outdated.Delegate vote: agree, 100% (9/9); disagree, 0%; abstain, 0%.(Unanimous, strongest consensus)CONSENSUS STATEMENT THREE: MRI findings should be part of a new classification system.Delegate vote: agree, 33% (3/9); disagree, 67% (6/9); abstain, 0%.(Weak negative consensus)CONSENSUS STATEMENT FOUR: Weightbearing CT (WBCT) findings should be part of a new classification system.Delegate vote: agree, 56% (5/9); disagree, 44% (4/9); abstain, 0%.(Weak consensus)CONSENSUS STATEMENT FIVE: A new classification system is proposed and should be used to stage the deformity clinically and to define treatment.Delegate vote: agree, 89% (8/9); abstain, 11% (1/9).(Strong consensus).

Effect of Isometric Hip Abduction on Foot and Ankle Muscle Activity and Medial Longitudinal Arch During Short-Foot Exercise in Individuals With Pes Planus.

CONTEXT: The improvement of hip joint stability can significantly impact knee and rearfoot mechanics. Individuals with pes planus have a weak abductor hallucis (AbdH), and the tibialis anterior (TA) may activate to compensate for this. As yet, no studies have applied isometric hip abduction (IHA) for hip stability during short-foot exercise (SFE). OBJECTIVE: To compare the effects of IHA on the muscle activity of the AbdH, TA, peroneus longus (PL), and gluteus medius (Gmed), as well as the medial longitudinal arch (MLA) angle during sitting and standing SFE. DESIGN: Two-way repeated analyses of variance were used to determine the statistical significance of AbdH, TA, PL, and Gmed electromyography activity, as well as the change in MLA angle. SETTING: University research laboratory. PARTICIPANTS: Thirty-two participants with pes planus. INTERVENTION(S): The participants performed SFE with and without isometric hip abduction in sitting and standing positions. MAIN OUTCOME MEASURES: Surface electromyography was used to measure the activity of the AbdH, TA, PL, and Gmed muscles, and Image J was used to measure the MLA angle. RESULTS: Significant interactions between exercise type and position were observed in terms of the PL muscle activity and in the change in MLA angle only, while other muscles showed significant main effects. The IHA during SFE significantly increased the AbdH muscle activity, while the TA muscle activity was significantly lower. The muscle activity of Gmed and PL was significantly increased in the standing position compared with sitting, but there was no significant difference with or without IHA. The change in the MLA angle was significantly greater in SFE with IHA in a standing position than in the other SFE conditions. CONCLUSIONS: IHA may be an effective method for reducing compensatory TA activity and increasing AbdH muscle activity during SFE for individuals with pes planus.

Weight-bearing CT Scans in Foot and Ankle Surgery.

Weight-bearing CT (WBCT) scans of the foot and ankle have improved the understanding of deformities that are not easily identified on radiographs and are increasingly being used by orthopaedic surgeons for diagnostic and preoperative planning purposes. In contrast to standard CT scans, WBCT scans better demonstrate the true orientation of the bones and joints during loading. They have been especially useful in investigating the alignment of complex pathologies such as adult-acquired flatfoot deformity in which patients have been found to have a more valgus subtalar joint alignment than in a normal cohort and high rates of subfibular impingement. Studies using WBCT scans have also provided new insight into more common lower extremity conditions such as hallux valgus, ankle fractures, and lateral ankle instability. WBCT scans have allowed researchers to investigate pronation of the first metatarsal in patients with hallux valgus compared with normal feet, and patients with lateral ankle instability have been found to have more heel varus than healthy control subjects. Understanding the application of WBCT scans to clinical practice is becoming more important as surgeons strive for improved outcomes in the treatment of complicated foot and ankle disorders.