Biomechanics and clinical analysis of the adult acquired flatfoot

Prognostic Power of Foot Mobility in Identifying the Risk of Musculoskeletal Injuries: A Cross-Sectional Study of Male Volleyball Players at Different Competitive Levels

(1) Background: The arch structure and mobility of the foot are considered injury risk factors in volleyball. However, there are limited studies presenting differences in injury prevalence and the risk of lower limb injuries in relation to the competitive level in male volleyball. Therefore, the main aim of the current study was to evaluate foot mobility (through navicular drop test) as an injury risk factor in volleyball players from different competitive levels. (2) Methods: The reliability and usefulness of navicular drop testing were initially assessed in test-retest procedures (based on a sample of eight participants and 16 feet measurements), with primary analyses conducted using foot measurements of the twelve top-level volleyball players (24 feet) and eighteen academic-level volleyball players (36 feet). The modified navicular drop test was conducted, and the feet were classified based on arch height, and injury prevalence was retrospectively assessed with a previously validated questionnaire. Chi-squared tests, receiver operating curves, and logistic regression were used as statistical methods. The navicular drop test was verified as a reliable tool by intraclass correlation coefficient (ICC) (3.1) analysis. (3) Results: There were no significant differences in injury prevalence between academic- and top-level volleyball players, though there was a significant relationship between pronated foot and injury risk independent of competitive level. Generally, for both groups, thresholds above 10 mm of the navicular drop were predictors of lower limb injuries. The risk of injury if the foot was pronated ranged from 70% (academic level) to over 90% (top-level players). However, no statistically significant effect of competitive level on the chance of injury was observed. (4) Conclusions: Our study found a high prevalence of foot injuries independently of competitive level. There was a relationship between pronation of the foot and the risk of injury. However, the risk of lower limb injury was higher in pronated top-level players. Also, a navicular drop greater than 10 mm was an excellent predictor of injuries at both competitive levels.

Case study: Gait assessment of a patient with hallux rigidus before and after plantar modification

INTRODUCTION AND IMPORTANCE

Hallux rigidus (HR) is a degenerative arthritis affecting the first metatarsophalangeal joint (MTP), leading to pain and functional impairment, particularly during the propulsive phase of walking. The prevalence of HR is about 2.5 % in individuals over 50, but younger individuals can also be affected, as demonstrated in this case.

CASE PRESENTATION

We report the case of a 26-year-old patient with a body mass index (BMI) of 20.2, who has been suffering from HR for 5 years. The patient presented with walking difficulties, characterized by a limp and impaired propulsion phase, and pain in the right foot due to HR. A comprehensive gait assessment was conducted using a baropodometric platform and integrated smartphone motion sensors. Following the diagnosis, a non-surgical intervention involving the application of a compressed cotton felt foot orthosis at the MTP plantar area was initiated. This intervention aimed to alleviate pain and improve the functional mobility of the right big toe. Post-treatment assessments showed an increase in the big toe's mobility from 0 degrees to 35 degrees, as measured by a digital goniometer.

CLINICAL DISCUSSION

The application of a soft support, such as compressed cotton felt, at the plantar area of MTP, demonstrated a potential non-surgical therapeutic approach to improve gait and reduce discomfort in HR patients.

CONCLUSION

This case study underscores the potential benefits of plantar modification in the management of HR.

Efficacy of Faradic Foot Baths and Short Foot Exercises in Symptomatic Flatfoot: A Review

Flatfoot is a common condition among adults, according to orthopedic experts. Flatfoot is defined in this document as a foot condition that occurs after the completion of skeletal growth and is characterized by either partial or complete reduction of the medial longitudinal arch (MLA). The purpose of this study was to evaluate the effects of short foot exercise (SFE) and faradic foot baths on people who have flat feet. This review focused on comprehensive original primary articles written in English. Numerous studies have been conducted in order to determine the effects of both interventions. The search yielded a wide range of papers, including editorials, review articles, freely available full texts, and abstracts. The results showed that both SFE and faradic foot baths effectively improved flat feet.

Cavovarus deformity of one foot with planovalgus deformity of the contralateral foot (Wind-swept heels): A case report

Normal alignment of the arches and adequate stability is essential for the foot to function correctly. Pes planus and pes cavus are fairly common foot deformities, but it is uncommon to see both in the same patient simultaneously. This study aimed to describe the clinical presentation and prognosis of an uncommon combination of bilateral foot abnormalities named “windswept heels” resembling windswept knees. A 43-year-old female employee experienced frequent pain in her right foot and swelling and pain in her left foot, mainly when walking barefoot. She had a severe cavovarus deformity of the right foot with pressure callosities on the lateral side, clawing of the toes, and a positive Coleman’s block test. With the loss of the medial arch, severe heel valgus, and forefoot abduction, the left foot developed a planovalgus deformity. The left foot’s talus-first metatarsal angle and the right foot’s calcaneal inclination angle increased on weight-bearing radiographs. The left foot underwent staged surgical treatments, including medial sliding calcaneal osteotomy, gastrocnemius recession, and cotton osteotomy. For the right foot, lateral sliding calcaneal osteotomy, plantar fasciotomy, and peroneus longus tendon transfer. The American Orthopaedics Foot and Ankle Society Score (AOFAS) was used to measure the clinical and functional outcomes. At 1 year, her AOFAS scale was 85 compared to 59 before surgery. Since this presentation resembles the windswept knee deformity, we propose calling this disorder windswept heel deformity.

Influence of the center of pressure on baropodometric gait pattern variations in the adult population with flatfoot: A case-control study

Background: Adult flatfoot is considered an alteration in the foot bone structure characterized by a decrease or collapse of the medial arch during static or dynamic balance in the gait pattern. The aim of our research was to analyze the center of pressure differences between the population with adult flatfoot and the population with normal feet.

Methods: A case-control study involving 62 subjects was carried out on 31 adults with bilateral flatfoot and 31 healthy controls. The gait pattern analysis data were collected employing a complete portable baropodometric platform with piezoresistive sensors.

Results: Gait pattern analysis showed statistically significant differences in the cases group, revealing lower levels in the left foot loading response of the stance phase in foot contact time (p = 0.016) and contact foot percentage (p = 0.019).

Conclusion: The adult population with bilateral flatfoot evidenced higher contact time data in the total stance phase compared to the control group, which seems to be linked to the presence of foot deformity in the adult population.

Injuries to the Spring Ligament: Nonoperative Treatment

The fibrocartilage within the superomedial calcaneonavicular (spring) ligament is part of an interwoven complex of ligaments that span the ankle, subtalar, and talonavicular joints. Acute isolated rupture of the spring ligament has been reported in association with an eversion ankle sprain. Attenuation and failure of the spring ligament causes complex 3D changes called the progressive collapsing foot deformity (PCFD). This deformity is characterized by hindfoot eversion, forefoot supination, collapse of the medial longitudinal arch, and forefoot abduction. Nonoperative treatment of an isolated spring ligament rupture and PCFD using various designs of orthoses have shown promising results.

Different Design Feature Combinations of Flatfoot Orthosis on Plantar Fascia Strain and Plantar Pressure: A Muscle-Driven Finite Element Analysis With Taguchi Method

Customized foot orthosis is commonly used to modify foot posture and relieve foot pain for adult acquired flexible flatfoot. However, systematic investigation of the influence of foot orthotic design parameter combination on the internal foot mechanics remains scarce. This study aimed to investigate the biomechanical effects of different combinations of foot orthoses design features through a muscle-driven flatfoot finite element model. A flatfoot-orthosis finite element model was constructed by considering the three-dimensional geometry of plantar fascia. The plantar fascia model accounted for the interaction with the bulk soft tissue. The Taguchi approach was adopted to analyze the significance of four design factors combination (arch support height, medial posting inclination, heel cup height, and material stiffness). Predicted plantar pressure and plantar fascia strains in different design combinations at the midstance instant were reported. The results indicated that the foot orthosis with higher arch support (45.7%) and medial inclination angle (25.5%) effectively reduced peak plantar pressure. For the proximal plantar fascia strain, arch support (41.8%) and material stiffness (37%) were strong influencing factors. Specifically, higher arch support and softer material decreased the peak plantar fascia strain. The plantar pressure and plantar fascia loading were sensitive to the arch support feature. The proposed statistics-based finite element flatfoot model could assist the insole optimization and evaluation for individuals with flatfoot.

Effects of a 6-Minute Fast-Walking Protocol on Changes in Muscle Activity in Individuals with Flatfoot

Flatfoot causes abnormal biomechanics in the lower extremity, resulting in discomfort and excessive burden on lower extremity muscles during functional tasks, and it potentially leads to associated syndromes in the lower extremity. The aim of this study was to investigate how a demanding, repetitive task affects the muscle strength, activities, and fatigue of the lower extremities during function tasks. Nineteen individuals with flexible flatfoot (10M9F, age: 24.74 ± 2.68 years) and fifteen non-flatfoot participants (6M9F, age: 24.47 ± 3.74) took part in this study. All participants performed maximal voluntary isometric contraction and functional tasks, including walking and single-leg standing tests before and immediately after a 6-min fast-walking protocol. A surface electromyography system was used to collect muscle activation data. Our results showed that, after 6 min of fast walking, peroneus longus activity increased only in the non-flatfoot group, and gastrocnemius activity increased in the flexible flatfoot group. In the flexible flatfoot group, greater recruitment in abductor halluces and greater fatigue in the tibialis anterior was observed. Individuals with flexible flatfoot showed altered muscle activation pattern after 6-min fast walking. These findings can provide an evidence-based explanation of associated syndromes in flatfoot populations and lead to potential intervention strategies in the future.

Angular and linear measurements of adult flexible flatfoot via weight-bearing CT scans and 3D bone reconstruction tools

Acquired adult flatfoot is a frequent deformity which implies multiple, complex and combined 3D modifications of the foot skeletal structure. The difficult thorough evaluation of the degree of severity pre-op and the corresponding assessment post-op can now be overcome by cone-beam (CBCT) technology, which can provide access to the 3D skeletal structure in weight-bearing. This study aims to report flatfoot deformities originally in 3D and in weight-bearing, with measurements taken using two different bone segmentation techniques. 21 such patients, with indication for surgical corrections, underwent CBCT (Carestream, US) while standing on one leg. From these scans, 3D models of each bone of the foot were reconstructed by using two different state-of-the-art segmentation tools: a semi-automatic (Mimics Innovation Suite, Materialise, Belgium), and an automatic (Bonelogic Ortho Foot and Ankle, Disior, Finland). From both reconstructed models, Principal Component Analysis was used to define anatomical reference frames, and original foot and ankle angles and other parameters were calculated mostly based on the longitudinal axis of the bones, in anatomical plane projections and in 3D. Both bone model reconstructions revealed a considerable valgus of the calcareous, plantarflexion and internal rotation of the talus, and typical Meary’s angles in the lateral and transverse plane projections. The mean difference from these angles between semi-automatic and automatic segmentations was larger than 3.5 degrees for only 3 of the 32 measurements, and a large number of these differences were not statistically significant. CBCT and the present techniques for bone shape reconstruction finally provide a novel and valuable 3D assessment of complex foot deformities in weight-bearing, eliminating previous limitations associated to unloaded feet and bidimensional measures. Corresponding measurements on the bone models from the two segmentation tools compared well. Other more representative measurements can be defined in the future using CBCT and these techniques.

Immediate effect of prefabricated and UCBL foot orthoses on alignment of midfoot and forefoot in young people with symptomatic flexible flatfoot: A radiographic evaluation

BACKGROUND

Radiographic imaging has been considered the gold standard in evaluating the skeletal alignment of the foot in static weightbearing. The effects of foot orthoses on the alignment of foot bones have been mostly evaluated using lateral view x-rays. The posterior-anterior view has not been investigated extensively.

OBJECTIVES

To investigate the effects of 2 foot orthoses: University of California Biomechanics Laboratory Orthosis (UCBL) and a prefabricated orthosis (P-FFO) on the alignment of foot bones on anterior-posterior x-rays in young people with symptomatic flexible flatfoot (SFF).

STUDY DESIGN

This is a randomized, crossover study.

METHODS

Fifteen participants (mean [SD], 23.67 ± 2 years) with SFF were randomly imaged in 3 different conditions: shoes only, shoes + P-FFO, and shoes + UCBL. The talonavicular coverage, the first and the second talometatarsal angles, the intermetatarsal angle, and the cuboid abduction angle (CAA) were measured on weightbearing, anterior-posterior x-ray images for each condition.

RESULTS

Both orthotic designs demonstrated a significant reduction in the talonavicular coverage, the first and the second talometatarsal angles, and the CAA compared with the shoe-only condition (P < .001). The talonavicular coverage angle reduced by ∼11% using P-FFO compared with UCBL (P < .005). No significant differences were observed for other angles between the 2 orthotic conditions.

CONCLUSIONS

Both orthotic conditions improved the talonavicular coverage, first and the second talometatarsal angle, and CAA in young people with SFF. The walls of the UCBL orthosis did not result in further correction of the talonavicular coverage angle compared with the prefabricated FFO design.

Analysis of the main soft tissue stress associated with flexible flatfoot deformity: a finite element study

A better understanding of soft tissue stress and its role in supporting the medial longitudinal arch in flexible flatfoot could help to guide the clinical treatment. In this study, a 3-Dimensional finite element (FE) foot model was reconstructed to measure the stress of the soft tissue, and its variation in different scenarios related to flexible flatfoot. All bones, cartilages, ligaments and related tendons around the ankle, and fat pad were included in the finite element model. The equivalent stress on the articular surface of the joints in the medial longitudinal arch and the maximum principal stress of the ligaments around the ankle were obtained. The results show that the plantar fascia (PF) is the main tissue in maintaining the medial longitudinal arch. The equivalent stress of all the joints in the medial longitudinal arch increases when the PF attenuation and the talonavicular joint increases, while other joints decreases when all the three tissue attenuation. Moreover, the maximum principal stress variation of calcaneofibular ligament is largest when the PF attenuation and the tibionavicular ligament and posterior tibiotalar ligament are largest when the posterior tibial tendon (PTT) attenuation. The maximum principal stress variation of tibionavicular ligament and posterior tibiotalar ligament are even larger when all the three tissue attenuation. These findings support that the PF is the main factor in maintaining the medial longitudinal arch. The medial longitudinal arch collapse mainly affects the talonavicular joint and the calcaneofibular ligament, the tibionavicular ligament and the posterior tibiotalar ligament. This approach could help to improve the understanding of adult-acquired flatfoot deformity (AAFD).

Current Trends in Treatment of Injuries to Spring Ligament

The spring ligament is the main static supporter of the medial longitudinal arch. Identifying every detail of the pathophysiology of each condition in which these structures are involved is the key to an appropriate approach and treatment. Isolated reconstruction of the posterior tibial tendon present long-term results with a high failure rate. It is important to diagnose spring ligament injuries because of the probable consequences if not treated, such as acquired flatfoot deformity and loss of correction of treated flatfoot. The option of surgical treatment is discussed in this article.

Peroneus Longus overload caused by soft tissue deficiencies associated with early adult acquired flatfoot: A finite element analysis

BACKGROUND

Peroneus Longus tendinopathy has been related to overload from cavus and ankle instability. The etiology of isolated Peroneus Longus tendon synovitis has not been elucidated. Loss of foot arch integrity as a cause of isolated Peroneus Longus overload is difficult to establish using cadaver modeling. Our objective was to analyze Peroneus Longus stress changes in pathological scenarios related to flatfoot development.

METHODS

A three-dimensional finite element foot model which included the foot bones and main soft tissues that maintain the arch was used. Simulations were performed in midstance of gait. Tendon's maximum principal stress and von Mises were calculated in scenarios where the plantar fascia, spring ligament and the posterior tibial tendon were weakened.

FINDINGS

Decreasing plantar fascia stiffness thus weakening arch integrity increases Peroneus Longus stresses by over three times. Additional failure of tissues that support arch, such as the spring ligament and tibialis posterior tendon further overloads this tendon. The absence of Peroneus Longus also affects stresses in tissues that maintain the arch. Stress concentrations increase in the plantar component of the Peroneus Longus.

INTERPRETATION

Results offer an explanation into isolated Peroneus Longus overload synovitis. Recognition of failing medial arch structures that occur in early acquired flatfoot as a cause of Peroneus Longus overload could help in its treatment. We caution the practice of transfer of peroneus brevis to longus in surgical treatment of flatfoot as it may further overload an overloaded tendon and focus should be on restoration of arch stability to offload stresses within it.

Influence of arch support heights on the internal foot mechanics of flatfoot during walking: A muscle-driven finite element analysis

BACKGROUND

Different arch support heights of the customized foot orthosis could produce different effects on the internal biomechanics of the foot. However, quantitative evidence is scarce. Therefore, we aimed to investigate and quantify the influence of arch support heights on the internal foot biomechanics during walking stance.

METHODS

We reconstructed a foot finite element model from a volunteer with flexible flatfoot. The model enabled a three-dimensional representation of the plantar fascia and its interactions with surrounding osteotendinous structures. The volunteer walked in foot orthosis with different arch heights (low, neutral, and high). Muscle forces during gaits were calculated by a multibody model and used to drive a foot finite element model. The foot contact pressures and plantar fascia strains in different regions were compared among the insole conditions at the first and second vertical ground reaction force (VGRF) peak and VGRF valley instants.

RESULTS

The results indicated that peak foot pressures decreased in balanced standing and second VGRF as the arch support height increased. However, peak midfoot pressures increased during all simulated instants. Meanwhile, high arch support decreased the plantar fascia loading by 5%-15.4% in proximal regions but increased in the middle and distal regions.

CONCLUSION

Although arch support could generally decrease the plantar foot pressure and plantar fascia loading, the excessive arch height may induce high midfoot pressure and loadings at the central portion of the plantar fascia. The consideration of fascia-soft tissue interaction in modeling could improve the prediction of plantar fascia strains towards design optimization for orthoses.

[Etiology, pathogenesis, clinical features, diagnostics and conservative treatment of adult flatfoot]

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.

Adult Acquired Flatfoot Deformity: Anatomy, Biomechanics, Staging, and Imaging Findings

Adult acquired flatfoot deformity (AAFD) is a common disorder that typically affects middle-aged and elderly women, resulting in foot pain, malalignment, and loss of function. The disorder is initiated most commonly by degeneration of the posterior tibialis tendon (PTT), which normally functions to maintain the talonavicular joint at the apex of the three arches of the foot. PTT degeneration encompasses tenosynovitis, tendinosis, tendon elongation, and tendon tearing. The malaligned foot is initially flexible but becomes rigid and constant as the disorder progresses. Tendon dysfunction commonly leads to secondary damage of the spring ligament and talocalcaneal ligaments and may be associated with injury to the deltoid ligament, plantar fascia, and other soft-tissue structures. Failure of multiple stabilizers appears to be necessary for development of the characteristic planovalgus deformity of AAFD, with a depressed plantar-flexed talus bone, hindfoot and/or midfoot valgus, and an everted flattened forefoot. AAFD also leads to gait dysfunction as the foot is unable to change shape and function adequately to accommodate the various phases of gait, which require multiple rapid transitions in foot position and tone for effective ambulation. The four-tier staging system for AAFD emphasizes physical examination findings and metrics of foot malalignment. Mild disease is managed conservatively, but surgical procedures directed at the soft tissues and/or bones become necessary and progressively more invasive as the disease progresses. Although much has been written about the imaging findings of AAFD, this article emphasizes the anatomy and function of the foot's stabilizing structures to help the radiologist better understand this disabling disorder. Online supplemental material is available for this article. ^©RSNA, 2019.

Effect of additional body weight on arch index and dynamic plantar pressure distribution during walking and gait termination

The medial longitudinal arch is considered as an essential feature which distinguishes humans from other primates. The longitudinal arch plays a supporting and buffering role in human daily physical activities. However, bad movement patterns could lead to deformation of arch morphology, resulting in foot injuries. The authors aimed to investigate any alterations in static and dynamic arch index following different weight bearings. A further aim was to analyze any changes in plantar pressure distribution characteristics on gait during walking and stopping, Twelve males were required to complete foot morphology scans and three types of gait tests with 0%, 10%, 20% and 30% of additional body weight. The dynamic gait tests included walking, planned and unplanned gait termination. Foot morphology details and plantar pressure data were collected from subjects using the Easy-Foot-Scan and Footscan pressure platform. No significant differences were observed in static arch index when adding low levels of additional body weight (10%). There were no significant changes observed in dynamic arch index when loads were added in the range of 20% to 30%, except in unplanned gait termination. Significant maximal pressure increases were observed in the rearfoot during walking and in both the forefoot and rearfoot during planned gait termination. In addition, significant maximum pressure increases were shown in the lateral forefoot and midfoot during unplanned gait termination when weight was increased. Findings from the study indicated that excessive weight bearing could lead to a collapse of the arch structure and, therefore, increases in plantar loading. This may result in foot injuries, especially during unplanned gait termination.

Biomechanics and Orthotic Treatment of the Adult Acquired Flatfoot

The adult acquired flatfoot deformity resulting from posterior tibial tendon dysfunction is the result of rupture of the posterior tibial tendon as well as key ligaments of the ankle and hindfoot. Kinematic studies have verified certain levels of deformity causing hindfoot eversion, lowering of the medial longitudinal arch and forefoot abduction. The condition is progressive and left untreated will cause significant disability. Bracing with ankle-foot orthoses has shown promising results in arresting progression of deformity and avoiding debilitating surgery. Various types of ankle-foot orthoses have been studied in terms of effects on gait as well as efficacy in treatment.

Using the Biomechanical Examination to Guide Therapy

In trying to explain the myriad of foot deformities and symptoms that have slow onset and/or are considered to be overuse syndromes, clinicians have been trying to develop quantitative examinations to describe the cause of the patient's problems and to better individualize treatment modalities. This type of examination is called a biomechanical examination. This article discusses some of the more common portions of a biomechanical examination of the foot and lower extremity. It will also point out some ways that the information from a biomechanical examination can be applied in clinically treating patients.

Flatfoot deformity affected the kinematics of the foot and ankle in proportion to the severity of deformity

BACKGROUND

Flatfoot deformity is thought to affect gait kinematics, but the effect of flatfoot on segmental motion of the foot during gait remains unclear. Recently, multi-segmental foot models (MFMs) have been introduced for the in vivo analysis of dynamic foot kinematics. The objective of this study was to find the effect of flatfoot on segmental motion of the foot during gait in females by comparisons with age and gender controlled healthy adults.

METHODS

Thirty six symptomatic flatfeet patients (52-80 years old) and 42 symptom-free female participants without flatfoot (60-69 years old) were included in this study. According to the Meary angle (MA) on standing lateral radiograph, flatfoot patients are divided into severe (SFF, MA>20°) and moderate (MFF, 10°<MA<20°) flatfoot group. Segmental foot kinematics were evaluated using a 3D MFM of a 15-marker set (DuPont Foot Model).

RESULTS

The cadence, speed, stride length, and step width are significantly lower in flatfoot patients. ROM of sagittal and transverse plane of the hindfoot, transverse plane of the forefoot and sagittal plane of the hallux were lower in severe flatfoot group. In the SFF group, there was loss of hindfoot adduction motion during the terminal stance and pre-swing phase. In forefoot kinematics, the SFF group showed significantly supinated and abducted position throughout the gait cycle. In hindfoot kinematics, plantar flexion motion in the pre-swing phase was significantly lower in flatfoot patients in proportion to the severity of the deformity.

CONCLUSIONS

We showed that flatfoot deformity affected the kinematics of the foot and ankle in proportion to the severity of deformity. We cautiously suggest that there might be a threshold of flatfoot precluding normal foot kinematics because normal kinematic pattern of the foot might not collapse in moderate flatfoot with a Meary angle of less than 20 degrees.

Evaluation and Treatment of Posterior Tibialis Tendon Insufficiency in the Elderly Patients

Introduction:

Posterior tibialis tendon insufficiency is the most common cause of adult acquired flatfoot deformity in elderly patients. We performed a literature search of primary and secondary journal articles pertaining to posterior tibialis tendon insufficiency in the geriatric population. We examined relevant data from these articles regarding current evaluation in addition to both conservative and advanced treatment approaches that correspond to disease severity.

Significance:

There is a paucity of literature to guide treatment of posterior tibialis tendon insufficiency in the elderly, and this condition may be more prevalent in geriatric patients than previously realized.

Results:

Posterior tibialis tendon insufficiency is an acquired defect that affects 10% of the geriatric population and disproportionately affects women. It is typically caused by degenerative changes. There are four primary stages of posterior tibialis tendon with subcategorizations that range from mild to severe. Conservative treatment with a variety of available ankle braces and non-steroidal anti-inflammatory medications are typically used to treat the first and second stage disease. Surgical repair is warranted for advanced second stage and above posterior tendon insufficiency. A variety of techniques have been proposed, and can include tendon transfer, hindfoot fusion, and even total ankle arthroplasty in extreme cases.

Conclusion:

Posterior tibialis tendon insufficiency causes marked discomfort and alters normal gait biomechanics. Elderly patients typically present with more severe manifestations of the disease. For patients requiring surgery, and especially geriatric patients, the ideal treatment is thought to be a procedure that is minimally invasive in order to maximize positive outcomes for elderly patients. More work is needed to examine clinical and radiographic outcomes of geriatric patients treated for posterior tibialis tendon insufficiency.

Biomechanical stress analysis of the main soft tissues associated with the development of adult acquired flatfoot deformity

BACKGROUND

Adult acquired flatfoot deformity (AAFD) is traditionally related to a tibialis posterior tendon deficiency. In the intermediate stages, treatments are commonly focused on reinforcing this tissue, but sometimes the deformation appears again over time, necessitating the use of more aggressive options. Tissue stress cannot be consistently evaluated through traditional experimental trials. Computational foot modeling extends knowledge of the disease and could help guide the clinical decisions. This study analyzes the biomechanical stress of the main tissues related to AAFD and their capacity to support the plantar arch.

METHODS

A FE foot model was reconstructed. All the bones, cartilages and tissues related to AAFD were included, respecting their biomechanical characteristics. The biomechanical tissue stress was quantified. The capacity of each soft tissue to support the plantar arch was measured, following clinical criteria.

FINDINGS

Biomechanical stress of the tibialis posterior tendon is considerably superior to both the plantar fascia and spring ligament stress. However, it cannot maintain the plantar arch by itself. Both the tibialis posterior tendon and spring ligament act in reducing the hindfoot pronation, while the plantar fascia is the main tissue that prevents arch elongation. The Achilles tendon action increases the plantar tissue stress.

INTERPRETATION

The tibialis posterior tendon stress increases when the spring ligament or the fascia plantar fails. These findings are consistent with the theory that regards the tibialis posterior tendon as a secondary actor because it cannot support the plantar arch and claudicates when the hindfoot has rotated around the talonavicular joint.

Intra- and interday reliability of the dynamic navicular rise, a new measure for dynamic foot function: A descriptive, cross-sectional laboratory study

BACKGROUND

The lack of reliable parameters to evaluate dynamic foot function, emphasizes the need for a deeper insight in foot biomechanics. The aims were to investigate the reliability of a new parameter (dynamic navicular rise dNR), and its relationship with the dynamic navicular drop (dND).

METHODS

Twenty healthy participants (mean age 30.2±8.1years) had to walk on even ground and downstairs. Data of ten trials per task on two measurement days were recorded. The dNR was defined as the difference in millimetres (mm) between the minimum navicular height (NH) during stance and the NH at toe off. To test intra- and interday reliability, Intraclass Correlation Coefficients (ICC_2.1) and repeatability were calculated. To obtain the absolute repeatability (RP) in mm, the equation RP=1.96×SD_differences was used. Furthermore, the relationship between the dNR and the dND was examined by calculating Pearson (r) or Spearman (r_s) correlation coefficients.

RESULTS

Included participants showed a mean dNR of (12.2±3.7) mm for level walking and (14.8±3.4) mm for stair descent. The ICC_2.1 for the dNR were 0.98 (intraday), 0.91 (interday) for level walking and 0.97 (intraday), 0.94 (interday) for stair descent. The interday repeatability was 3.2mm (level walking), 2.7mm (stair descent) respectively. For level walking, r was 0.31 (p=0.049), and r_s=0.88 (p<0.001) for stair descent.

CONCLUSIONS

The dNR seems to be highly reliable (ICCs), however, repeatability is unacceptable. For level walking, the dNR might be an independent measure, but not for stair climbing.

Factors affecting insole usage in patients with Pes planus

Abstract: Introduction: Insoles and exercise programs are the main treatment methods for pes planus patients. Insole using may prevent the formation of pain in daily activities as well as increasing the quality of walking. The aim of this study was to investigate insole usage time and the factors affecting this situation in patient with pes planus. Materials and Methods: 136 patients with pes planus who were prescribed an insole, included in the study. We invited patients to participate in a telephone survey. Patients' demographics, insole usage time, reasons to quit and the quitting time were questioned. Insole usage rates and the demographic data of patients were compared. Results: Of the 136 patients included in the present study, 80 were women (59%) and 56 were male (31%). 86 of these patients used an insole six months and over, 15 of them used shorter than six months and 35 of them bought the insoles but they didn't use it (63%, 11% and 26% respectively ). The average age of patients who used insoles was 32.80 ± 18.14 and who did not use insoles was 40.77 ± 12.54 (p = 0.04). 33.8 percent of women and 14.3 percent of men did not use insoles. This difference is statistically significant (p = 0.04). We did not find any significant relationship between height, weight, body mass index values and usage of insoles (p > 0:05). Conclusion: The use of insoles in treating patients with pes planus is widely accepted and may be affected by the demographics such as gender and age. Besides wearing comfort, female sex and older age should be considered that may affect the use of insoles.

Effect of total-contact orthosis on medial longitudinal arch and lower extremities in flexible flatfoot subjects during walking

BACKGROUND

Total-contact orthosis (TCO) is one kind of foot orthosis (FO) that is used to adjust biomechanics in flexible flatfoot.

OBJECTIVE

To determine the effects of a TCO on the MLA moment, MLA deformation angle and lower limb biomechanics.

STUDY DESIGN

Cross-sectional study.

METHODS

Seven-flatfoot and thirteen-normal foot subjects were recruited by footprint and radiographs. The biomechanics of subjects with normal foot (NF), flatfoot with shoe only (FWOT) and flatfoot with TCO (FWT) were collected in a 3D motion analysis laboratory and force plates. The MLA and lower limb biomechanics in each condition during specific sub-phases of stance were analyzed.

RESULTS

The NF had larger MLA eversion moment after shod walking ( p = 0.001). The FWT condition compared with the FWOT condition had a significantly larger peak MLA upward moment ( p = 0.035) during pre-swing, larger peak knee external rotation angle ( p = 0.040) during mid stance, smaller peak knee extension moment during terminal stance ( p = 0.035) and a larger ground reaction force in the anterior-posterior direction during early stance ( p < 0.05).

CONCLUSION

Our study found positive effects from the customized TCOs which included an increased TCO angle that led to a decreased peak MLA moment in the frontal plane in flexible flatfoot subjects during walking. Clinical relevance Lower limb biomechanics is different from normal in subjects with flexible flatfoot. The design of a TCO affects MLA, ankle and knee biomechanics and may be used to clinically correct biomechanical changes in flexible flatfoot.

Flat Foot in a Random Population and its Impact on Quality of Life and Functionality

INTRODUCTION

Flat foot is a common deformity in adults. It is characterized by medial rotation and plantar flexion of the talus, eversion of the calcaneus, collapsed medial arch and abduction of the forefoot.

AIM

The aim of this study was to determine the prevalence of flat foot and its impact on quality of life, dependence, foot pain, disability and functional limitation among random population of 40-year-old and above.

MATERIALS AND METHODS

A cross-sectional study in a random population sample from Cambre (A Coruña-Spain) (n=835) was performed (α =0.05; Precision=±3.4%). The diagnosis of flat foot was stablished by the study of the footprint obtained with a pedograph. Anthropometric variables were studied, Charlson's Comorbidity Index, function and state of foot (Foot Function Index (FFI), Foot Health Status Questionnaire (FHSQ)), quality of life (SF-36), and dependence for activities of daily living (Barthel and Lawton index). A logistic and linear multiple regression analysis was performed.

RESULTS

The prevalence of flat foot was 26.62%. Patients with flat foot were significantly older (65.73±11.04 vs 61.03±11.45-year-old), showed a higher comorbidity index (0.92±1.49 vs 0.50±0.98), had a greater BMI (31.45±5.55 vs 28.40±4.17) and greater foot size (25.16±1.66 vs 24.82±1.65). The presence of flat foot diminishes the quality of life, as measured by the FHSQ, and foot function, measured by the FFI. The presence of flat foot does not alter the physical and mental dimension of the SF-36 or the degree of dependence.

CONCLUSION

Flat foot was associated with age, Charlson's Comorbidity Index, BMI and foot size. The SF-36, Barthel and Lawton questionnaires remained unaltered by the presence of flat foot. The FHSQ and FFI questionnaires did prove to be sensitive to the presence of flat foot in a significant manner.

Imaging of adult flatfoot: correlation of radiographic measurements with MRI

OBJECTIVE. The purpose of this study is to determine whether radiographic foot measurements can predict injury of the posterior tibial tendon (PTT) and the supporting structures of the medial longitudinal arch as diagnosed on MRI. MATERIALS AND METHODS. After institutional review board approval, 100 consecutive patients with radiographic and MRI examinations performed within a 2-month period were enrolled. Thirty-one patients had PTT dysfunction clinically, and 69 patients had other causes of ankle pain. Talonavicular uncoverage angle, incongruency angle, calcaneal pitch angle, Meary angle, cuneiform-to-fifth metatarsal height, and talar tilt were calculated on standing foot or ankle radiographs. MRI was used to assess for abnormalities of the PTT (tenosynovitis, tendinosis, and tear) and supporting structures of the medial longitudinal arch (spring ligament, deltoid ligament, and sinus tarsi). Statistical analysis was performed using the chi-square and Fisher exact tests for categoric variables; the Student t test was used for continuous variables. RESULTS. There was a statistically significant association of PTT tear with abnormal talonavicular uncoverage angle, calcaneal pitch angle, Meary angle, and cuneiform-to-fifth metatarsal height. PTT tendinosis and isolated tenosynovitis had a poor association with most radiologic measurements. If both calcaneal pitch and Meary angles were normal, no PTT tear was present. An abnormal calcaneal pitch angle had the best association with injury to the supporting medial longitudinal arch structures. CONCLUSION. Radiographic measurements, especially calcaneal pitch and Meary angles, can be useful in detecting PTT tears. Calcaneal pitch angle provides the best assessment of injury to the supporting structures of the medial longitudinal arch.

Donor site morbidity of the medial plantar artery flap studied with gait and pressure analysis

BACKGROUND

The medial plantar artery flap (MPA) allows transfer of both glabrous (smooth and free from hair) and sensate tissue. It has been suggested that the non-weight bearing instep area of the foot provides tissue for transfer with minimal donor morbidity. However the abductor hallucis muscle and plantar fascia are dissected during flap harvest which may affect foot mechanics.

METHODS

Patients were included who had undergone MPA flap harvest and were walking unaided. The majority of the patients studied had problems with soft tissues of their heels rather than trauma as a starting point. Laboratory normals and the patient's contralateral limb were used as controls. Gait and pressure analysis were performed using 3D gait analysis and high resolution pressure analysis.

RESULTS

This study included 6 patients, with 5 chronic wounds (4 ipsilateral, 1 contralateral) and 1 traumatic ankle defect.

QUESTIONNAIRE RESULTS

Enneking scores: 67.9% return to function; Foot Function Index scores: 39.1% loss of function.

GAIT ANALYSIS

Significant differences were seen in kinetic and kinematic data.

PRESSURE ANALYSIS

The donor site group had significantly less pressure in the great toe (38.1kPa vs. 78.1kPa, p=0.013), significantly slower transition through the midfoot (445.2ms vs. 352.07ms, p=0.016) and increased impulse in the heel (3.1kPa/s vs. 11.7kPa/s, p=0.038).

CONCLUSIONS

This study demonstrates subjective and objective evidence of MPA donor site morbidity. Comparison to other studies looking at gait and pressure changes seen after flap reconstruction of the plantar region suggest that much of this difference may be attributable to ipsilateral reconstruction. As the majority had chronic problems with the soft tissues over the heel some of these biomechanical responses could be related to learned behaviour preoperatively or continued discomfort in the heel pad. Nonetheless it demonstrates accurately the effect of the technique overall on the function of the foot. The changes in the region of the great toe may be solely attributable to MPA harvest. These results suggest that MPA harvest is not free of donor morbidity.

Procedure selection for the flexible adult acquired flatfoot deformity

Adult acquired flatfoot represents a spectrum of deformities affecting the foot and the ankle. The flexible, or nonfixed, deformity must be treated appropriately to decrease the morbidity that accompanies the fixed flatfoot deformity or when deformity occurs in the ankle joint. A comprehensive approach must be taken, including addressing equinus deformity, hindfoot valgus, forefoot supinatus, and medial column instability. A combination of osteotomies, limited arthrodesis, and medial column stabilization procedures are required to completely address the deformity.

Surgical management of stage 2 adult acquired flatfoot

Adult acquired flatfoot deformity is a progressive disorder with multiple symptoms and degrees of deformity. Stage II adult acquired flatfoot can be divided into stage IIA and IIB based on severity of deformity. Surgical procedures should be chosen based on severity as well as location of the flatfoot deformity. Care must be taken not to overcorrect the flatfoot deformity so as to decrease the possibility of lateral column overload as well as stiffness.

Forefoot supinatus

The supination of the forefoot that develops with adult acquired flatfoot is defined as forefoot supinatus. This deformity is an acquired soft tissue adaptation in which the forefoot is inverted on the rearfoot. Forefoot supinatus is a reducible deformity. Forefoot supinatus can mimic, and often be mistaken for, a forefoot varus. A forefoot varus differs from forefoot supinatus in that a forefoot varus is a congenital osseous deformity that induces subtalar joint pronation, whereas forefoot supinatus is acquired and develops because of subtalar joint pronation. This article discusses the acquired form of forefoot supinatus.

Plantar measurements to determine success of surgical correction of Stage IIb adult acquired flatfoot deformity

Adult acquired flatfoot deformity is a degenerative disease causing medial arch dysfunction. Surgical correction has typically involved tendon reconstruction with calcaneal osteotomy; however, the postoperative changes have not been fully characterized. The present study assessed the success of surgical correction of Stage IIb adult acquired flatfoot deformity through changes in plantar pressures and patient-generated outcome scores. With Institutional Review Board approval, 6 participants were evaluated before and after surgery using pedobarography, the Foot and Ankle Outcome Score, and the Medical Outcomes Study 36-item short-form questionnaire. The plantar pressures were recorded using a TekScan HRMat(®) during walking and in a 1- and 2-foot stance. The resulting contour maps were segmented into 9 regions, with the peak pressure, normalized force, and arch index calculated. Surgical effects were analyzed using paired t tests. Postoperatively, the Foot and Ankle Outcome Score and Medical Outcomes Study 36-item short-form questionnaire scores increased significantly from 180 ± 78 to 360 ± 136 (p < .03) and 47 ± 18 to 71 ± 19 (p = .06), respectively. During the 2-foot stance, the normalized force had increased significantly in the lateral midfoot (p < .03), although no significant differences were found in peak pressures. No significant differences were observed in the 1-foot stance. During walking, the normalized force increased significantly in the lateral mid- and forefoot (p < .05). The peak pressure increased significantly in the lateral forefoot (p < .01). The arch index values demonstrated no significant changes. The increased questionnaire scores indicated that surgical correction improved the self-perceived health of the participants. Lateral shifts in the peak pressure and normalized force suggest that forefoot and midfoot loading is altered postoperatively, consistent with the goal of offloading the dysfunctional arch. Thus, the present study has demonstrated that surgical treatment of adult acquired flatfoot deformity can be accurately assessed using patient-reported outcome measures and plantar pressures.

The effect of backpack load on muscle activities of the trunk and lower extremities and plantar foot pressure in flatfoot

[Purpose] The purpose of this study was to investigate the changes in muscle activation of the trunk and lower extremities and plantar foot pressure due to backpack loads of 0, 10, 15, and 20% of body weight during level walking in individuals with flatfoot. [Methods] Fourteen young flatfoot subjects and 12 normal foot subjects participated in this study. In each session, the subjects were assigned to carry a backpack load, and there were four level walking modes: (1) unloaded walking (0%), (2) 10% body weight (BW) load, (3) 15% BW load, and (4) 20% BW load. Trunk and lower extremity muscle activities were recorded by surface EMG, and contact area and plantar foot pressure were determined using a RS scan system. [Results] The erector spinae, vastus medialis, tibialis anterior and gastrocnemius muscle activities, but not the rectus femoris and rectus abdominis muscle activities of flatfoot subjects significantly and progressively increased as load increased in flatfoot subjects. Contact area and pressure of the lateral and medial heel zones were significantly increased too. [Conclusion] Based on this data, the weight of a backpack could influence muscle activation and plantar foot pressure in flatfoot.

Plantar pressure distribution in a hyperpronated foot before and after intervention with an extraosseous talotarsal stabilization device-a retrospective study

Plantar pressure measurements have long been used by clinicians to provide information regarding potential impairments and disorders of the foot and ankle. Elevations in peak plantar pressures or a poor distribution of these pressures can be an indication of pathomechanics in the foot. Lower extremity deficits such as sensory impairment, foot deformities, limited joint mobility, and reduced plantar tissue thickness have been associated with high plantar pressures. The total pressures, pressure distribution, and peak pressures provide useful information to evaluate the abnormal functioning of the talotarsal joint. Instability of the talotarsal joint can result in excessive forces exerted on the joints and surrounding tissues in the foot that can then lead to dysfunction of the proximal musculoskeletal kinetic chain. In the present study, we performed a retrograde analysis of the pre- and postoperative measurements of the peak plantar pressures, peak forces, and area of contact between the foot and the ground during each phase of the gait cycle for 6 patients (12 feet) who had undergone a bilateral extraosseous talotarsal stabilization procedure using a type II extraosseous talotarsal stabilization device. After the procedure, a significant reduction was seen in the peak pressures (42%) over the entire foot and a significant increase in the contact area (19.7%) between the foot and the floor. This could imply that the extraosseous talotarsal stabilization procedure was effective in stabilizing the talotarsal joint complex, thus eliminating abnormal hindfoot motion and restoring the normal biomechanics of the foot and ankle complex, as indicated by a reduction and realignment of the peak plantar pressures and forces.

Management of the rigid arthritic flatfoot in adults: triple arthrodesis

The traditional surgical treatment for adults with a rigid, arthritic flatfoot is a dual-incision triple arthrodesis. Over time, this procedure has proved to be reliable and reproducible in obtaining successful deformity correction through fusion and good clinical results. However, the traditional dual-incision triple arthrodesis is not without shortcomings. Early complications include lateral wound problems, malunion, and nonunion. Long-term follow-up of patients after a triple arthrodesis has shown that many develop adjacent joint arthritis at the ankle or midfoot. This particular problem should be considered an expected consequence, rather than a failure of the procedure. Although the indications for and surgical techniques used in triple arthrodesis have evolved and improved with time (predictably improving results in the intermediate term), the triple arthrodesis should be regarded as a salvage procedure. Certain measures can be taken by the surgeon to avoid some problems. If patients are at risk for lateral wound complications, the arthrodesis could be performed through a single medial incision. However, this can make some aspects of the CC fusion more difficult. Implants would have to be inserted percutaneously, which prevents the surgeon from using either staples or plates. If a patient were to need a lateral column lengthening through a CC distraction fusion, this would not be possible medially. If either the ST or CC joints have minimal degenerative changes, they could be spared through a double or modified double arthrodesis, respectively. Although these procedures that deviate from the traditional triple arthrodesis offer promise, further study is required to better define their role in treatment of the rigid, arthritic AAFD. Triple arthrodesis is, by no means, a simple surgery. It requires preoperative planning, meticulous preparation of bony surfaces, cognizance of hindfoot positioning, and rigidity of fixation. The procedure also requires enough experience on the part of the operating surgeon to anticipate postoperative problems and provide modifications in traditional technique for certain patients.

Measuring medial longitudinal arch deformation during gait. A reliability study

Clinical evaluation of medial longitudinal arch deformation (MLAD) during walking gait is often estimated from static measures of e.g. navicular drop (ND) measured during quiet standing. The aim of the present study was to test the reliability of a new three-dimensional method of measuring the MLAD during gait and to compare this method with a static measure and a 2D dynamic method. Fifty-two feet (26 healthy male participants) were tested twice 4-9 days apart in a biomechanical gait analysis laboratory using a 3D three-marker foot model, a 2D video-based model for the measurement of MLAD during gait, and ND for measurements of MLAD during quiet standing. The 3D method showed the highest test-retest reliability among the measurements of MLAD. Furthermore, the ND showed only moderate correlation with both measurements of MLAD during gait. The new 3D method was found to be highly reliable and showed that ND obtained during quiet standing could not predict the MLAD during gait. The 3D method, or alternatively the 2D method, may be used in clinical settings as reliable methods for easy estimation of the foot longitudinal stability.

Effect of extra-osseous talotarsal stabilization on posterior tibial tendon strain in hyperpronating feet

Posterior tibial tendon dysfunction is considered one of the most common causes of progressive adult acquired flatfoot deformity. The etiology leading to the dysfunction of posterior tibial tendon remains controversial. The purpose of this study was to quantify strain on the posterior tibial tendon in cadaver feet exhibiting hyperpronation caused by flexible instability of the talotarsal joint complex. We hypothesized that posterior tibial tendon strain would decrease after a minimally invasive extra-osseous talotarsal stabilization procedure. A miniature differential variable reluctance transducer was used to measure the elongation of posterior tibial tendon in 9 fresh-frozen cadaver specimens. The elongation was measured as the foot was moved from its neutral to maximally pronated position, before and after intervention with the HyProCure(®) extra-osseous talotarsal stabilization device. The mean elongation of the posterior tibial tendon (with respect to a fixed reference point) was found to be 6.23 ± 2.07 mm and 3.04 ± 1.85 mm, before and after intervention, respectively (N = 27; variation is ± 1 SD). The average elongation reduced by 51% and was statistically significant with p < .001. Strain on the posterior tibial tendon is significantly higher in hyperpronating feet. An extra-osseous talotarsal stabilization procedure reduces excessive abnormal elongation of the posterior tibial tendon by minimizing excessive abnormal pronation. This minimally invasive procedure may thus provide a possible treatment option to prevent or cure posterior tibial tendon dysfunction in patients exhibiting flexible instability of the talotarsal joint complex.

Effects of surgical correction for the treatment of adult acquired flatfoot deformity: a computational investigation

Computational models of the foot/ankle complex were developed to predict the biomechanical consequences of surgical procedures that correct for stage II adult acquired flatfoot deformity. Cadaveric leg and foot bony anatomy was captured by CT imaging in neutral flexion and imported to the modeling software. Ligaments were approximated as tension only springs attached at insertion sites. Muscle contraction of the gastrocnemius/soleus complex was simulated through force vectors and desired external loads applied to the model. Ligament stiffnesses were modified to reflect stage II flatfoot damage, followed by integration of corrective osteotomies-medializing calcaneal osteotomy (MCO) and Evans and calcaneocuboid distraction arthrodesis (CCDA)--to treat flatfoot. Joint angles, tissue strains, calcaneocuboid contact force, and plantar loads were analyzed. The flatfoot simulation demonstrated clinical signs of disease evidenced by degradation of joint alignment. Repair states corrected these joint misalignments with MCO having greatest impact in the hindfoot, and Evans/CCDA having greatest effect in the mid- and forefoot. The lateral procedures unevenly strained plantar structures, while offloading the medial forefoot, and increased loading on the lateral forefoot, which was amplified by combining with MCO. The Evans procedure raised calcaneocuboid joint contact force to twice intact levels. Computational results are in agreement with clinical and experimental findings. The model demonstrated potential precursors to such complications as lateral tightness and arthritic development and may thus be useful as a predictor of surgical outcomes.

Nonoperative care for the treatment of adult-acquired flatfoot deformity

Nonoperative therapy for adult-acquired flatfoot is a reasonable treatment option that is likely to be beneficial for most patients. In this article, we describe the results of a retrospective cohort study that focused on nonoperative measures, including bracing, physical therapy, and anti-inflammatory medications, used to treat adult-acquired flatfoot in 64 consecutive patients. The results revealed the incidence of successful nonsurgical treatment to be 87.5% (56 of 64 patients), over the 27-month observation period. Overall, 78.12% of the patients with adult-acquired flatfoot were obese (body mass index [BMI] ≥ 30), and 62.5% of the patients who failed nonsurgical therapy were obese; however, logistic regression failed to show that BMI was statistically significantly associated with the outcome of treatment. The use of any form of bracing was statistically significantly associated with successful nonsurgical treatment (fully adjusted OR = 19.8621, 95% CI 1.8774 to 210.134), whereas the presence of a split-tear of the tibialis posterior on magnetic resonance image scans was statistically significantly associated with failed nonsurgical treatment (fully adjusted OR = 0.016, 95% CI 0.0011 to 0.2347). The results of this investigation indicate that a systematic nonsurgical treatment approach to the treatment of the adult-acquired flatfoot deformity can be successful in most cases.

The relationship of body mass index, age and triceps-surae musculotendinous stiffness with the foot arch structure of postmenopausal women

BACKGROUND

Low- or high-arched feet and insufficient or excessive muscle-tendon stiffness have been identified as risk factors for lower extremity injuries. Additionally, increased body mass index and age may be responsible for structural changes of the foot, which might adversely affect the functional capacity of the longitudinal arch. Therefore, the aim of this study was to investigate the relationship of body mass, age and triceps-surae musculotendinous stiffness with the foot arch structure of postmenopausal women.

METHODS

81 post menopausal women (58.0 (SD 6.0) years) participated. An in vivo free oscillation technique was used to assess musculotendinous stiffness of the ankle. The two-step protocol was used to acquire gait plantar pressure data. Dynamic arch index was calculated as the ratio of the midfoot area to the area of the entire foot excluding the toes. Three groups were formed (cavus, normal and planus).

FINDINGS

Significant differences (P<0.05) between the groups cavus and planus were found for age using the ANOVA test. Using Kruskal-Wallis tests significant differences were found for body mass index between the cavus-normal groups and cavus-planus (P<0.001) but no significant differences were found for triceps-surae musculotendinous stiffness between foot-type groups.

INTERPRETATION

Since obese subjects present greater downward vertical forces, they might be more prone to overload foot structures leading to the collapse of the medial longitudinal arch affecting adversely the functional capacity of the foot. Deterioration of the musculoskeletal system, due to age, may also affect foot arch structure. No relationship between musculotendinous stiffness and foot arch structure appears to exist.

Foot pain: biomechanical basics as a guide for assessment and treatment

A large percentage of Americans will likely have a foot problem in their lifetime. Foot pain has a multitude of diagnoses; however, most can be properly diagnosed with a basic understanding of the biomechanics of gait. For pain-free ambulation, human feet go through a series of rotatory motions involving pronation and supination. Pathologic biomechanics are generally divided into excessive pronation or excessive supination. Treatment is often directed at minimizing the pathologic biomechanical forces to assist with pain-free walking.

Determination of normal values for navicular drop during walking: a new model correcting for foot length and gender

Background

The navicular drop test is a measure to evaluate the function of the medial longitudinal arch, which is important for examination of patients with overuse injuries. Conflicting results have been found with regard to differences in navicular drop between healthy and injured participants. Normal values have not yet been established as foot length, age, gender, and Body Mass Index (BMI) may influence the navicular drop. The purpose of the study was to investigate the influence of foot length, age, gender, and BMI on the navicular drop during walking.

Methods

Navicular drop was measured with a novel technique (Video Sequence Analysis, VSA) using 2D video. Flat reflective markers were placed on the medial side of the calcaneus, the navicular tuberosity, and the head of the first metatarsal bone. The navicular drop was calculated as the perpendicular distance between the marker on the navicular tuberosity and the line between the markers on calcaneus and first metatarsal head. The distance between the floor and the line in standing position between the markers on calcaneus and first metatarsal were added afterwards.

Results

280 randomly selected participants without any foot problems were analysed during treadmill walking (144 men, 136 women). Foot length had a significant influence on the navicular drop in both men (p < 0.001) and women (p = 0.015), whereas no significant effect was found of age (p = 0.27) or BMI (p = 0.88). Per 10 mm increase in foot length, the navicular drop increased by 0.40 mm for males and 0.31 mm for females. Linear models were created to calculate the navicular drop relative to foot length.

Conclusion

The study demonstrated that the dynamic navicular drop is influenced by foot length and gender. Lack of adjustment for these factors may explain, at least to some extent, the disagreement between previous studies on navicular drop. Future studies should account for differences in these parameters.

Revision of failed flatfoot surgery

Revision of failed flatfoot surgery presents a unique and challenging dilemma for the foot and ankle surgeon. Revision surgery is focused on establishing a plantigrade foot with correction of the hindfoot valgus, midfoot abduction, and forefoot varus. Successful reconstruction of failed flatfoot surgery begins with a proper evaluation. No treatment algorithm exists for the management of the malaligned flatfoot. Patient complaints, an understanding of the initial deformity and biomechanical problems, and surgeon experience play a role in correction of failed flatfoot surgery.