Relationships between segmental foot mobility and plantar loading in individuals with and without diabetes and neuropathy

The purpose of our study was to examine dynamic foot function during gait as it relates to plantar loading in individuals with DM (diabetes mellitus and neuropathy) compared to matched control subjects. Foot mobility during gait was examined using a multi-segment kinematic model, and plantar loading was measured using a pedobarograph in subjects with DM (N = 15), control subjects (N = 15). Pearson product moment correlation was used to assess the relationship between variables of interest. Statistical significance and equality of correlations were assessed using approximate tests based on Fisher's Z transformation (α = 0.05). In individuals with DM, first metatarsal sagittal plane excursion during gait was negatively associated with pressure time integral under the medial forefoot (r = ?0.42 and ?0.06, DM and Ctrl, P = 0.02). Similarly, lateral forefoot sagittal plane excursion during gait was negatively associated with pressure time integral under the lateral forefoot (r = ?0.56 and ?0.11, DM and Ctrl, P = 0.02). Frontal plane excursion of the calcaneus was negatively associated with medial (r = ?0.57 and 0.12, DM and Ctrl, P < 0.01) and lateral (r = ?0.51 and 0.13, DM and Ctrl, P < 0.01) heel and medial forefoot pressure time integral (r = ?0.56 and ?0.02, DM and Ctrl, P < 0.01). The key findings of our study indicate that reductions in segmental foot mobility were accompanied by increases in local loading in subjects with DM. Reduction in frontal plane calcaneal mobility during walking serves as an important functional marker of loss of foot flexibility in subjects with DM.     

Contoured in-shoe foot orthoses increase mid-foot plantar contact area when compared with a flat insert during cycling

ObjectivesTo determine the effect of contouring of an in-shoe foot orthosis on plantar contact area and surface pressure, as well as perceived comfort and support at the foot-orthosis interface during stationary cycling.DesignA randomised, repeated measures control study.MethodsTwelve cyclists performed steady-state seated cycling at a cadence of 90 rpm using a contoured orthosis and a flat insert of similar hardness. Contact area (CA) and plantar mean pressure (PP) were measured using the PEDAR^® system, determined for seven discrete plantar regions and represented as the percentage of the total CA and PP respectively (CA% and PP%). Perceived comfort and support were rated using a visual analogue scale (VAS).ResultsThe contoured orthosis produced a significantly greater CA% at the medial midfoot (p = 0.001) and lateral midfoot (p = 0.009) with a standardised mean difference (SMD) of 1.3 and 0.9 respectively. The contoured orthosis also produced a significantly greater PP% at the hallux (p = 0.003) compared to the flat insert with a SMD of 1.1. There was a small non-significant effect (SMD < 0.4) for the perceived comfort measures between conditions, but perceived support was significantly greater at the arch (p = 0.000) and heel (p = 0.013) with the contoured orthoses (SMD of 1.5 and 0.9, respectively).ConclusionsContoured orthoses influenced the plantar surface of the foot by increasing contact area as well as a perception of greater support at the midfoot while increasing relative pressure through the hallux when compared to a flat insert during stationary cycling. No difference in perceived comfort was noted.     

Effect of shoe type on plantar pressure: A gender comparison

Despite the differences in materials, racing flats have begun to be used not only for racing, but also for daily training. As there are data suggesting a gender difference in overuse injuries in runners, shoe choice may affect loading patterns during running. The purpose was to determine differences in plantar pressure between genders when running in training shoes and racing flats. In-shoe plantar pressure data were collected from 34 subjects (17m, 17f) who ran over-ground in both a racing flat and training shoe. Contact area (CA), maximum force (MF), and contact time under the entire foot and beneath eight foot regions were collected. Each variable was analyzed using a shoe by gender repeated measures ANOVA (α = 0.05). In men, MF was increased in the racing flats (p = 0.016) beneath the medial midfoot (MMF), yet was increased beneath the medial forefoot (MFF) in the training shoe (p = 0.018). Independent of gender, CA was decreased in the racing flats beneath the entire foot (p = 0.029), the MMF (p = 0.013), and the MFF (p = 0.030), and increased beneath the lateral forefoot (LFF) (p = 0.023). In the racing flats, MF was increased beneath the entire foot (p < 0.001) and the LFF (p < 0.001). Independent of the shoe, CA was decreased in men beneath the MFF (p = 0.007) and middle forefoot (p < 0.001), while MF was increased in the LFF (p = 0.002). The LFF is an area of increased stress fracture risk in men. Based on the gender differences in loading, running shoe design should be gender specific in an attempt to prevent injuries.     

Comparaison de la répartition des appuis plantaires entre chaussures d'entraînement et chaussures à pointes chez de jeunes sprinters

AimsTo compare plantar patterns between training and spikes shoes in young sprinters.Methods and resultsEleven athletes performed two trials of 2 × 60 m maximal speed with training and spikes shoes, respectively. Contact area was significantly smaller with spikes in total and under the toes; pressure and force were significantly higher with spikes under the forefoot mainly in medial and lateral.ConclusionsWearing spikes shoes, higher loads are applied mainly under the 1st and the 2nd metatarsal heads. This may have relevance in order to clarify the mechanisms of injuries like metatarsalgia or stress fractures of the forefoot.     

Dose–response effects of customised foot orthoses on lower limb muscle activity and plantar pressures in pronated foot type

Customised foot orthoses (FOs) featuring extrinsic rearfoot posting are commonly prescribed for individuals with a symptomatic pronated foot type. By altering the angle of the posting it is purported that a controlled dose–response effect during the stance phase of gait can be achieved, however these biomechanical changes have yet to be characterised. Customised FOs were administered to participant groups with symptomatic pronated foot types and asymptomatic normal foot types. The electromyographic (EMG) and plantar pressure effects of varying the dose were measured. Dose was varied by changing the angle of posting from 6° lateral to 10° medial in 2° steps on customised devices produced using computer aided orthoses design software. No effects due to posting level were found for EMG variables. Significant group effects were seen with customised FOs reducing above knee muscle activity in pronated foot types compared to normal foot types (biceps femoris p = 0.022; vastus lateralis p < 0.001; vastus medialis p = 0.001). Interaction effects were seen for gastrocnemius medialis and soleus. Significant linear effects of posting level were seen for plantar pressure at the lateral rearfoot (p = 0.001), midfoot (p < 0.001) and lateral forefoot (p = 0.002). A group effect was also seen for plantar pressure at the medial heel (p = 0.009). This study provides evidence that a customised FOs can provide a dose response effect for selected plantar pressure variables, but no such effect could be identified for muscle activity. Foot type may play an important role in the effect of customised orthoses on activity of muscles above the knee.     

Abnormalities of plantar pressure distribution in early,intermediate, and late stages of diabetic neuropathy

Inconsistent findings with regard to plantar pressure while walking in the diabetic population may be due to the heterogeneity of the studied groups resulting from the classification/grouping criteria adopted. The clinical diagnosis and classification of diabetes have inherent uncertainties that compromise the definition of its onset and the differentiation of its severity stages. A fuzzy system could improve the precision of the diagnosis and classification of diabetic neuropathy because it takes those uncertainties into account and combines different assessment methods. Here, we investigated how plantar pressure abnormalities evolve throughout different severity stages of diabetic polyneuropathy (absent, n = 38; mild, n = 20; moderate, n = 47; severe, n = 24). Pressure distribution was analysed over five areas while patients walked barefoot. Patients with mild neuropathy displayed an increase in pressure–time integral at the forefoot and a lower peak pressure at the heel. The peak and pressure–time integral under the forefoot and heel were aggravated in later stages of the disease (moderate and severe) compared with early stages of the disease (absent and mild). In the severe group, lower pressures at the lateral forefoot and hallux were observed, which could be related to symptoms that develop with the aggravation of neuropathy: atrophy of the intrinsic foot muscles, reduction of distal muscle activity, and joint stiffness. Although there were clear alterations over the forefoot and in a number of plantar areas with higher pressures within each severity stage, they did not follow the aggravation evolution of neuropathy classified by the fuzzy model. Based on these results, therapeutic interventions should begin in the early stages of this disease to prevent further consequences of the disease.     

In-shoe plantar pressure measurements for the evaluation and adaptation of foot orthoses in patients with rheumatoid arthritis: A proof of concept study

ObjectivesImproving foot orthoses (FOs) in patients with rheumatoid arthritis (RA) by using in-shoe plantar pressure measurements seems promising. The objectives of this study were to evaluate (1) the outcome on plantar pressure distribution of FOs that were adapted using in-shoe plantar pressure measurements according to a protocol and (2) the protocol feasibility.MethodsForty-five RA patients with foot problems were included in this observational proof-of concept study. FOs were custom-made by a podiatrist according to usual care. Regions of Interest (ROIs) for plantar pressure reduction were selected. According to a protocol, usual care FOs were evaluated using in-shoe plantar pressure measurements and, if necessary, adapted. Plantar pressure–time integrals at the ROIs were compared between the following conditions: (1) no-FO versus usual care FO and (2) usual care FO versus adapted FO. Semi-structured interviews were held with patients and podiatrists to evaluate the feasibility of the protocol.ResultsAdapted FOs were developed in 70% of the patients. In these patients, usual care FOs showed a mean 9% reduction in pressure–time integral at forefoot ROIs compared to no-FOs (p = 0.01). FO adaptation led to an additional mean 3% reduction in pressure–time integral (p = 0.05). The protocol was considered feasible by patients. Podiatrists considered the protocol more useful to achieve individual rather than general treatment goals. A final protocol was proposed.ConclusionsUsing in-shoe plantar pressure measurements for adapting foot orthoses for patients with RA leads to a small additional plantar pressure reduction in the forefoot. Further research on the clinical relevance of this outcome is required.     

A biomechanical assessment of the acute hallux abduction manipulation intervention

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

Abnormalities of plantar pressure distribution in early,intermediate, and late stages of diabetic neuropathy

Inconsistent findings with regard to plantar pressure while walking in the diabetic population may be due to the heterogeneity of the studied groups resulting from the classification/grouping criteria adopted. The clinical diagnosis and classification of diabetes have inherent uncertainties that compromise the definition of its onset and the differentiation of its severity stages. A fuzzy system could improve the precision of the diagnosis and classification of diabetic neuropathy because it takes those uncertainties into account and combines different assessment methods. Here, we investigated how plantar pressure abnormalities evolve throughout different severity stages of diabetic polyneuropathy (absent, n = 38; mild, n = 20; moderate, n = 47; severe, n = 24). Pressure distribution was analysed over five areas while patients walked barefoot. Patients with mild neuropathy displayed an increase in pressure–time integral at the forefoot and a lower peak pressure at the heel. The peak and pressure–time integral under the forefoot and heel were aggravated in later stages of the disease (moderate and severe) compared with early stages of the disease (absent and mild). In the severe group, lower pressures at the lateral forefoot and hallux were observed, which could be related to symptoms that develop with the aggravation of neuropathy: atrophy of the intrinsic foot muscles, reduction of distal muscle activity, and joint stiffness. Although there were clear alterations over the forefoot and in a number of plantar areas with higher pressures within each severity stage, they did not follow the aggravation evolution of neuropathy classified by the fuzzy model. Based on these results, therapeutic interventions should begin in the early stages of this disease to prevent further consequences of the disease.     

Adaptive changes of foot pressure in hallux valgus patients

BackgroundHallux valgus (HV) is one of the most common deformities in podiatric and orthopedic practice. Plantar pressure technology has been widely used in studying the pressure distribution in HV patients for better assessment to plan interventions. However, previous studies produced an array of controversial findings and most of them only focused on the forefoot.MethodsWe examined the dynamic changes of foot pressure of the whole foot with a large-sample investigation (229 patients and 35 controls). Foot pain, which has been largely neglected previously, was used to group the participants.ResultsCompared to healthy controls, patients had significantly higher loading of the first and second metatarsals, where the transverse arch usually collapses, and significantly less loading of the hallux. Moreover, forces in most regions reached their maximum late, indicating a slow build-up of loading. Patients shortened the loading duration on their forefoot, loaded more on the medial foot starting from early foot contact, and delayed the medial-to-lateral load transition. Notably, nearly all these changes were more pronounced in patients with pain.ConclusionsBiomechanical changes in HV patients are not only caused by physical deformity but also by modified neural control strategies, possibly to alleviate discomfort and to accommodate the foot deformity. Our results suggest that dynamic evaluation of the whole foot and consideration of foot pain are necessary for the functional assessment of foot pressure in HV patients. The foot balance changes have important clinical implications.     

Gait biomechanics evaluation of the treatment effects for hallux valgus patients: A systematic review and meta-analysis

BackgroundHallux valgus (HV) is a foot deformity characterized by lateral deviation of the big toe and medial deviation of the first metatarsal.Research questionThis study aimed to shed light on the treatment effects of different interventions and surgical procedures for HV deformity to determine the effectiveness of gait biomechanics correction.MethodsEnglish-language searches of the electronic databases were conducted in the Cochrane Library, Web of Science, PubMed, Scopus, and Embase. Gait biomechanics evaluation before and after conservative or operative treatments was essential for inclusion in this review. Methodological quality was assessed by the Institute of Health Economics (IHE) quality appraisal tool. All pooled analysis was based on the random-effects model.ResultsTwenty-five articles (1003 participants) were identified in this review. Three studies chose conservative therapies for HV deformity, incorporating foot orthotics and minimalist running intervention, and surgeries were performed in twenty-two studies. For the pressure parameter alteration under the hallux, the effect size (ES) in the conservative treatment subgroup was − 0.95 with 95%CI [− 1.69, − 0.21]. It demonstrated a moderate ES of − 0.44% and 95%CI [− 0.81, − 0.07] in the surgery subgroup. The five operations’ peak pressure alteration under the hallux demonstrated a moderate ES of − 0.45% and 95%CI [− 0.54, − 0.36].SignificanceBoth non-operative and operative treatments could achieve the forefoot pressure redistribution, decreasing loading beneath the hallux and first metatarsal regions，However, the treatment effects of surgeries were not very robust. The percutaneous DSTR-Akin technique is recommended as an adequate operative treatment, with a large ES and moderate heterogeneity. The negative gait return effect should be noticed while using Scarf osteotomy, despite positive clinical and radiographic outcomes.     

Torsion deformity and joint loading for medial knee osteoarthritis

PurposeThe consequences of lower limb torsion deformity on knee loading in knee osteoarthritis are poorly understood. The purpose of this study was to quantify the associations between the mechanical axis, tibial torsion and knee loading in subjects with medial knee OA and in controls.MethodsTwenty-four subjects: end-staged medial knee osteoarthritis (OA) with apparent torsion deformity (TKO, n = 6) and without torsion deformity (KOA, n = 8) and controls (CON, n = 10) were imaged using long standing lower extremity (LSLE) radiographs and computed tomography (CT). Medial knee loading was assessed using the internal knee varus moment determined by gait analysis. The LSLE mechanical axis, CT tibial torsion and the foot progression angle were used to predict medial knee loading.ResultsThe TKOs had significantly greater mechanical axis varus and knee varus moment compared to KOAs and CONs. The regression model predicting medial knee loading using the mechanical axis (β = 0.898), tibial torsion (β = 0.264) and foot progression angle (β = −0.369) showed a goodness of fit of 0.774.ConclusionsMedial knee loading was predicted by the mechanical axis and the foot progression angle. Future longitudinal studies are needed to assess the role of tibial intorsion during disease progression and following total knee replacement surgery.     

In-shoe plantar pressure distribution during running on natural grass and asphalt in recreational runners

The type of surface used for running can influence the load that the locomotor apparatus will absorb and the load distribution could be related to the incidence of chronic injuries. As there is no consensus on how the locomotor apparatus adapts to loads originating from running surfaces with different compliance, the objective of this study was to investigate how loads are distributed over the plantar surface while running on natural grass and on a rigid surface—asphalt. Forty-four adult runners with 4 ± 3 years of running experience were evaluated while running at 12 km/h for 40 m wearing standardised running shoes and Pedar insoles (Novel). Peak pressure, contact time and contact area were measured in six regions: lateral, central and medial rearfoot, midfoot, lateral and medial forefoot. The surfaces and regions were compared by three ANOVAS (2 × 6). Asphalt and natural grass were statistically different in all variables. Higher peak pressures were observed on asphalt at the central (p < 0.001) [grass: 303.8(66.7) kPa; asphalt: 342.3(76.3) kPa] and lateral rearfoot (p < 0.001) [grass: 312.7(75.8) kPa; asphalt: 350.9(98.3) kPa] and lateral forefoot (p < 0.001) [grass: 221.5(42.9) kPa; asphalt: 245.3(55.5) kPa]. For natural grass, contact time and contact area were significantly greater at the central rearfoot (p < 0.001). These results suggest that natural grass may be a surface that provokes lighter loads on the rearfoot and forefoot in recreational runners.     

Can we predict outcome of surgical reconstruction of Charcot neuroarthropathy by dynamic plantar pressure assessment?—A proof of concept study

The joint deformity that arises as a result of Charcot neuroarthropathy, leads to gait modification. Ulceration risk associated with the deformity is generally assessed by measuring plantar pressure magnitude (PPM). However, as PPM is partially dependent on gait speed and treatment interventions may impact speed, the use of PPM to validate treatment is not ideal. This study suggests a novel assessment protocol, which is speed independent and can objectively (1) characterize abnormality in dynamic plantar loading in patients with foot Charcot neuroarthropathy and (2) screen improvement in dynamic plantar loading after foot reconstruction surgery. To examine whether the plantar pressure distribution (PPD) measured using EMED platform, was normal, a customized normal distribution curve was created for each trial. Then the original PPD was fitted to the customized normal distribution curve. This technique yields a regression factor (RF), which represents the similarity of the actual pressure distribution with a normal distribution. RF values may range from negative 1 to positive 1 and as the value increases positively so does the similarity between the actual and normalized pressure distributions. We tested this novel score on the plantar pressure pattern of healthy subjects (N = 15), Charcot patients pre-operation (N = 4) and a Charcot patient post-foot reconstruction (N = 1). In healthy subjects, the RF was 0.46 ± 0.1. When subjects increased their gait speed by 29%, PPM was increased by 8% (p < 10^?5), while RF was not changed (p = 0.55), suggesting that RF value is independent of gait speed. In preoperative Charcot patients, the RF < 0, however, RF increased post-surgery (RF = 0.42), indicating a transition to normal plantar distribution after Charcot reconstruction.     

Effects of flexible and rigid rocker profiles on in-shoe pressure

Rocker profiles are commonly used in the prevention of diabetic foot ulcers. Rockers are mostly stiffened to restrict toe plantarflexion to ensure proper offloading. It is also described that toe dorsiflexion should be restricted. However, the difference in effect on plantar pressure between rigid rockers that restrict this motion and flexible rockers that do not is unknown. In-shoe plantar pressure data were collected for a control shoe and the same shoe with rigid and flexible rockers with the apex positioned at 50% and 60%. For 29 healthy female adults peak plantar pressure (PP), maximum mean pressure (MMP) and force-time integral (FTI) were determined for seven regions of the foot. Generalized estimate equation was used to analyse the effect of the different shoes on the outcome measures for these regions. Compared to the control shoe a significant increase of PP and FTI was found at the first toe for both rigid rockers and the flexible rocker with the apex positioned at 60%, while MMP was significantly increased in rockers with an apex position of 60% (p < 0.001). PP at the first toe was significantly lower in flexible rockers when compared to rigid rockers (p < 0.001). For both central and lateral forefoot PP and MMP were significantly more reduced in rigid rockers (p < 0.001), while for the medial forefoot no differences were found. The use of rigid rockers results in larger reductions of forefoot plantar pressures, but in worse increase of plantar pressures at the first toe compared to rockers that allow toe dorsiflexion.     

Radiographic-directed local coordinate systems critical in kinematic analysis of walking in diabetes-related medial column foot deformity

Diabetic foot deformity onset and progression maybe associated with abnormal foot and ankle motion. The modified Oxford multi-segmental foot model allows kinematic assessment of inter-segmental foot motion. However, there are insufficient anatomical landmarks to accurately representation the alignment of the hindfoot and forefoot segments during model construction. This is most notable for the sagittal plane which is referenced parallel to the floor, allowing comparison of inter-segmental excursion but not capturing important sagittal hind-to-forefoot deformity associated with diabetic foot disease and can potentially underestimate true kinematic differences. The purpose of the study was to compare walking kinematics using local coordinate systems derived from the modified Oxford model and the radiographic directed model which incorporated individual calcaneal and 1st metatarsal declination pitch angles for the hindfoot and forefoot. We studied twelve participants in each of the following groups: (1) diabetes mellitus, peripheral neuropathy and medial column foot deformity (DMPN+), (2) DMPN without medial column deformity (DMPN−) and (3) age- and weight-match controls. The modified Oxford model coordinate system did not identify differences between groups in the initial, peak, final, or excursion hindfoot relative to shank or forefoot relative to hindfoot dorsiflexion/plantarflexion during walking. The radiographic coordinate system identified the DMPN+ group to have an initial, peak and final position of the forefoot relative to hindfoot that was more dorsiflexed (lower arch phenotype) than the DMPN− group (p < .05). Use of radiographic alignment in kinematic modeling of those with foot deformity reveals segmental motion occurring upon alignment indicative of a lower arch.     

The immediate effects of hallux valgus orthoses: A comparison of orthosis designs

BackgroundHallux valgus orthoses are available in a wide range of designs and materials, but the effects of their design on functional performance have not been fully investigated.Research questionThis present study aims to comprehensively analyze the immediate effects of soft and semi-rigid hallux valgus orthoses on balance, plantar pressure, hallux valgus angle, and subjective sensations.MethodsSixteen female subjects have participated in the study, including 10 subjects with healthy feet and 6 with hallux valgus. Three conditions are tested, including in the barefoot and using two types of commercially available hallux valgus orthoses. The subjects participate in static and dynamic (walking) tests with the use of the Novel Pedar® system. The peak pressure values in the hallux, lateral toes, first metatarsophalangeal joint, 2-4th metatarsal heads, 5th metatarsal head, medial midfoot, lateral midfoot and rearfoot in the various foot conditions are examined and compared. The hallux valgus angle of each subject is measured based on their footprint. Their subjective feelings towards the orthoses are also evaluated. A repeated-measures analysis of variance, and independent-sample t-test are performed.ResultsThe correction of the hallux valgus angle is statistically significant when the subjects with hallux valgus use the orthoses. In comparing the two types of orthoses, the use of the orthosis made of soft materials results in correction in the hallux valgus angle and higher wear comfort, and lower plantar pressure in hallux area.SignificanceThe results provide insights into the design of hallux valgus orthoses, thus offering practical reference for the selection of hallux valgus orthosis with compromise between functional performance and wear comfort.     

Reliability of peak foot pressure in patients with previous diabetic foot ulceration

BackgroundPrevious reliability studies on peak plantar pressure measurements in patients with previous diabetic foot ulceration (DFU) did not stratify their analyses according to whether the foot had a previous ulcer.Research questionDoes test-retest reliability of peak foot pressure measurements from the various foot regions differ between the ulcerated and non-ulcerated feet?MethodsData from 23 participants with peripheral neuropathy and healed plantar DFU were analysed in this test-retest reliability comparison study. Plantar pressure was evaluated on two sessions using Pedar^®-X in-shoe system, with a mean of 7.2 days (SD = 1.6) between sessions.ResultsThe intraclass correlation coefficient (ICC) and coefficient of variation (CV) were calculated for 10 foot regions. Overall, test-retest reliability was excellent (ICCs, 0.82 to 0.95) for all peak pressure variables. CV ranged between 6.3% and 18.3%, and exceeded 15% over the hallux and medial forefoot regions in the ulcer foot (18.3% and 16.4%, respectively). Hallux peak pressure CV was significantly higher over the ulcer foot than over the non-ulcer foot (5.7%, 95% CI, 1.7%–10.2%). Peak pressure CV over the forefoot also tended to be higher over the ulcer foot (medial forefoot: 6.1%, 95% CI, -0.5%–14.5%; lateral forefoot: 4.1%, 95%CI, -0.7%–11.1%).SignificancePeak plantar foot pressure may be useful to distinguish between groups of patients with peripheral neuropathy and healed plantar DFU. However, clinical decisions based on ulcer foot hallux and forefoot peak pressure measurements should be interpreted with caution.     

Landing technique affects knee loading and position during athletic tasks

Anterior cruciate ligament (ACL) injuries have been reported to occur with the ankle in a dorsiflexed position at initial contact. Few studies have attempted to quantify the biomechanical parameters related with such landing patterns during athletic tasks.ObjectivesThe purpose of this study was to evaluate the effects that two landing techniques have in lower extremity biomechanics while performing two tasks.DesignSingle-group repeated measures design.MethodsTwenty female soccer athletes from a Division I institution performed two landing techniques (forefoot and rearfoot) during two unanticipated tasks (sidestep cutting and pivot). Repeated measures analyses of variance were conducted to assess differences in the kinematic and kinetic parameters between landing techniques for each task.ResultsThe forefoot landing technique had significantly higher internal knee adductor moment than the rearfoot for both the pivot and sidestep cutting task (p < 0.001 and p = 0.003, respectively). For the sidestep cutting task, participants had increased knee valgus angle with the rearfoot, whereas for the pivot they had increased knee valgus with the forefoot landing technique (p < 0.05).ConclusionsThe results of this study highlighted that there are inherent differences in biomechanical outcomes between foot-landing techniques. The forefoot landing technique increasingly affects knee adduction moment loading, which can potentially place a higher strain on the ACL. Essentially, the demands of the landing technique on lower extremity biomechanics (e.g., hip and knee) are task dependent.     

Can the Foot Posture Index or their individual criteria predict dynamic plantar pressures?

The Foot Posture Index (FPI) quantifies foot posture through the evaluation of six individual criteria. The objective of the present study was then to establish the plantar pressure differences between types of feet, and to study the capacity of the whole FPI value and the six individual criteria to predict the pattern of plantar pressures.In a sample of 400 healthy subjects (201 men and 199 women), the FPI was evaluated and plantar pressures were measured in 10 zones using the Footscan^® platform. Five plantar pressures measurements were made for each foot, using for the study the mean of these measurements for each subject's left foot.The hallux and the lesser toes had lower pressure indices in highly supinated feet, with the values increasing progressively toward the highly pronated feet (p < 0.001 and p = 0.019 respectively). The fifth metatarsal head (MTH) values were greater in highly supinated feet, and decreased in the highly pronated feet (p < 0.001). The FPI value predicts low variability of plantar pressures, mainly in the heel and midfoot, while the individual criteria predict higher variability in the forefoot. The talonavicular prominence and the calcaneal frontal plane position was the most influential criterion, explaining 8.5% of the hallux pressure and 11.1% of the fifth MTH pressure. Neither talar head palpation nor the supra and infra malleolar curvature predicted any of the plantar pressures variables.The FPI can distinguish three groups of feet – pronated, neutral, and supinated. Its individual criteria predict moderate or low plantar pressures variability, with the talonavicular prominence being the most influential criterion.