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We developed an intravaginal instrumented probe (covered with a 10×10 matrix of capacitive sensors) for assessing the three-dimensional (3D) spatiotemporal pressure profile of the vaginal canal. The pressure profile was compared to the pelvic floor (PF) digital assessment, and the reliability of the instrument and repeatability of the protocol was tested. We also tested its ability to characterize and differentiate two tasks: PF maximum contraction and Valsalva maneuver (maximum intra-abdominal effort with downward movement of the PF). Peak pressures were calculated for the total matrix, for three major sub-regions, and for 5 planes and 10 rings throughout the vaginal canal. Intraclass correlation coefficients indicated excellent inter- and intra-rater reliability and intra-trial repeatability for the total and medial areas, with moderate reliability for the cranial and caudal areas. There was a moderate correlation between peak pressure and PF digital palpation [Spearman's coefficient r=0.55 (p

Background Skeletal muscle strength is poorly described and understood in diabetic participants with diabetic peripheral neuropathy. This study aimed to investigate the extensor and flexor torque of the knee and ankle during concentric, eccentric, and isometric contractions in men with diabetes mellitus type 2 with and without diabetic peripheral neuropathy. Methods Three groups of adult men (n = 92), similar in age, body mass index, and testosterone levels, were analyzed: 33 non-diabetic controls, 31 with type 2 diabetes mellitus, and 28 with diabetic peripheral neuropathy. The peak torques in the concentric, eccentric, and isometric contractions were evaluated using an isokinetic dynamometer during knee and ankle flexion and extension. Findings Individuals with diabetes and diabetic peripheral neuropathy presented similar low concentric and isometric knee and ankle torques that were also lower than the controls. However, the eccentric torque was similar among the groups, the contractions, and the joints. Interpretation Regardless of the presence of peripheral neuropathy, differences in skeletal muscle function were found. The muscle involvement does not follow the same pattern of sensorial losses, since there are no distal-to-proximal impairments. Both knee and ankle were affected, but the effect sizes of the concentric and isometric torques were found to be greater in the participants' knees than in their ankles. The eccentric function did not reveal differences between the healthy control group and the two diabetic groups, raising questions about the involvement of the passive muscle components.

The rearfoot angle (RFA) is a biomechanical variable widely used to determine the rearfoot motion (RM). Shoe manufacturers began to develop running shoes with RM control that would supposedly alter foot-ground interaction mechanics and neutralize excessive pronation or supination; moreover, some studies have not shown differences in rearfoot motion in shod condition compared to barefoot. This study intended to answer three questions: Do the shoes runners wear correspond to their respective barefoot RM? Does the eversion angle change during shod running, regardless the shoes worn? Can footwear designed for a specific RM (supination, pronation, neutral) correct or neutralize the eversion angle of runners? One hundred and eleven runners (38.6 ± 9.7years; 74.9 ± 12.0kg; 1.74 ± 0.08 m), who ran an average of 32 ± 17km/week, were included in this cross-sectional study. They had their RFA measured by a motion capture system when running barefoot and wearing their habitual running shoes (shod condition). Chi-squared test was used to assess associations between barefoot and shod condition and RFA was compared between conditions using Wilcoxon tests (p = 0.05). There was no association between the type of running shoe and barefoot RM (p > 0.05). There was an association between RFA when barefoot and when shod (p < 0.05). Among all participants classified as neutral, 61% continued to exhibit a normal/neutral RFA when wearing their habitual shoes. Among the overpronators, 100% showed a change in the RM to either normal or supinator. Among the participants classified as supinators, 62% exhibited normal pronation when shod even without using the appropriate footwear, claimed by the manufacturer. Only 44.1% of the sample chose the correct running shoe for their barefoot RM. The majority of runners did not choose their shoes designed for their natural type of RM. The rearfoot eversion angle changed an average 4 degrees when running shod and the RM barefoot altered quite a lot when using a running shoe. The running shoes did not correct the pronation detected barefoot, as claimed by the manufacturers.

Purpose: To quantify how postural stability is modified during experimental pain while performing different cognitively demanding tasks. Methods: Sixteen healthy young adults participated in the experiment. Pain was induced by intramuscular injection of hypertonic saline solution (1 mL, 6%) in both vastus medialis and vastus lateralis muscles (0.9% isotonic saline was used as control). The participants stood barefoot in tandem position for 1 min on a force plate. Center of pressure (CoP) was recorded before and immediately after injections, while performing two cognitive tasks: (i) counting forwards by adding one; (ii) counting backwards by subtracting three. CoP variables—total area of displacement, velocity in anterior–posterior (AP-velocity) and medial–lateral (ML-velocity) directions, and CoP sample entropy in anterior–posterior and medial–lateral directions were displayed as the difference between the values obtained after and before each injection and compared between tasks and injections. Results: CoP total area (− 84.5 ± 145.5 vs. 28.9 ± 78.5 cm 2) and ML-velocity (− 1.71 ± 2.61 vs. 0.98 ± 1.93 cm/s) decreased after the painful injection vs. Control injection while counting forward (P < 0.05). CoP total area (12.8 ± 53.9 vs. − 84.5 ± 145.5 cm 2), ML-velocity (− 0.34 ± 1.92 vs. − 1.71 ± 2.61 cm/s) and AP-velocity (1.07 ± 2.35 vs. − 0.39 ± 1.82 cm/s) increased while counting backwards vs. forwards after the painful injection (P < 0.05). Conclusion: Pain interfered with postural stability according to the type of cognitive task performed, suggesting that pain may occupy cognitive resources, potentially resulting in poorer balance performance.

Background Prevention of diabetic foot ulcers is important. Preventative treatment mostly targets and aims to improve modifiable risk factors of foot ulceration. While effectiveness of interventions in ulcer prevention has been systematically reviewed, their effectiveness in improving modifiable risk factors is unknown. Methods The available medical scientific literature in PubMed, Excerpta Medica Database, and the Cochrane database was searched for original research studies on six interventions to treat modifiable risk factors for diabetic foot ulceration (ie, education for patients; education for professionals; self-management; pre-ulcer treatment; orthotic interventions; and foot- and mobility-related exercises). We assessed interventions for eight outcomes (ie, patients' knowledge; treatment adherence; professionals' knowledge; pre-ulcers; mechanical stress; neuropathy symptoms; foot/ankle joint mobility; and foot function). Both controlled and noncontrolled studies were selected. Data from controlled studies were assessed for methodological quality by two independent reviewers and extracted and presented in evidence and risk of bias tables. Results We included 72 publications (26 with a controlled study design and 46 noncontrolled). We found that structured education may improve foot self-care behaviour of patients, yearly foot examinations, and foot disease knowledge of health care professionals. Callus removal reduces peak plantar pressure. Custom-made therapeutic footwear can be effective in reducing plantar pressure and may reduce callus. Foot- and mobility-related exercises may improve neuropathy symptoms and foot and ankle joint range of motion, while they do not seem to reduce peak plantar pressure; evidence for their effect on foot strength is conflicting. Conclusions Structured education for patients and health care professionals, callus removal, custom-made therapeutic footwear, and foot- and mobility-related exercises may be beneficial for improving modifiable risk factors for foot ulceration. However, we generally found low quality of evidence for interventions targeting modifiable risk factors for ulceration in persons with diabetes, with frequently inconsistent or limited results available per intervention and outcome.

Background: The control of foot trajectory during swing phase is important to achieve safe clearance with the ground. Complexity of a physiological control system arises from the interaction of structural units and regulatory feedback loops that operate to enable the organism to adapt to a non-static environment. Diabetic polyneuropathy (DPN) impairs peripheral feedback inputs and alters ankle control during gait, which might affect toe clearance (ToC) parameters and its complexity, predisposing DPN-subjects to tripping and falling. Research question: How do different DPN-severity degrees change ToC trajectory and minimum ToC, and its complexity during gait of diabetic subjects? Methods: 15 healthy controls and 69 diabetic subjects were assessed and classified into DPN-severity degrees by an expert fuzzy model: absent (n = 26), mild (n = 21) and severe (n = 22). Three-dimensional kinematics was measured during comfortable walking. ToC was the minimum vertical distance between the marker placed at the first metatarsal head and the ground during swing. Mean ToC, ToC standard deviation (SD) between trials, and sample entropy (SaEn) and standard deviation (SD) of ToC trajectory were calculated from the ToC temporal series. ANOVA and ANCOVA (with the walking speed as the covariate) and Bonferroni pairwise post-hoc tests (P < 0.05) were used to compare groups. Results: Mean ToC and ToC SD did not show differences between groups (ANCOVA F = 0.436; df = 3; P = 0.705; F=1.719; df=3; P=0.170, respectively). ToC trajectory SD also did not show differences between groups (ANCOVA F = 3.98; df = 3; P = 0.755). Severe-DPN subjects showed higher ToC_Traj_SaEn than controls (ANCOVA F=2.60; df=3; P = 0.05). Significance: Severe-DPN subjects showed a more complex pattern of overall foot-ankle trajectory in swing phase in comparison to controls, although did not present lower minimum ToC values. The higher complexity of ToC might lead to an increase in the motor system output (more strategies, increase in variability), resulting in a more unstable system and selected motor strategies.

The pelvic floor has been poorly studied from a biomechanical perspective probably because of its complex structure comprised of many muscle layers and multiple muscle insertions with concave format in a three-dimensional architecture. An objective assessment of the pelvic floor muscles' (PFM) physical and mechanical capabilities is highly recommended to document changes in PFM function throughout rehabilitation protocols. Besides the magnitude of PFM force-generating capacity, other force/pressure-related parameters are important for the continence mechanism and sexual function, which are also correlated to different urogynecological dysfunctions. The existing devices for PFM assessment can be classified as manometers, dynamometers, electromyographers, or imaging techniques. So far, there is no perfect instrument or gold standard; however, each method has its advantages and disadvantages, and some of them will be discussed in this chapter. Recently, a new objective and reliable mechanical tool has been developed, being capable of measuring the magnitude and spatiotemporal distribution of pressures along the vaginal canal, taking into account the PFM structure, the directions of PFM contractions, and its ventro-cephalic resultant force. In this chapter, this device will be described and some of its clinical applications will be shown.

AimsTo develop and validate the content of a free web-based software (desktop and mobile applications) for the self-management of and customised foot-ankle exercises for people with diabetes and diabetic neuropathy.MethodsThe development of the programme was based on gamification principles and addressed three main areas: foot care recommendations; self-assessment of feet according to the main complications of diabetic neuropathy; and customised foot-ankle exercises to strengthen muscles, increase the range of motion and improve functionality. The content was validated using the Delphi methodology and a quantitative approach in two rounds with diabetes specialists (n = 9) and users with diabetes (n = 20). A 70% approval rate was considered sufficient in the second round for final validation purposes. The data analysis was conducted using descriptive statistics, absolute and relative frequencies and the content-validity index (CVI).ResultsAmong specialists, the CVI was 0.812 after the first round, and final approval was 100% after the second round. Among users, the CVI was 0.902 in the first round, and the final approval was 97%.ConclusionThis free access web software was developed based on the high agreement rating between specialists and users and has the potential to prevent complications arising from diabetic polyneuropathy. It allows for self-monitoring and promotes personalised exercises, following a preventive model that can be applied in primary and secondary care services as a complementary treatment for chronic complications. However, further steps to validate the software in a larger population are recommended.

To quantify how postural stability is modified during experimental pain while performing different cognitively demanding tasks.Sixteen healthy young adults participated in the experiment. Pain was induced by intramuscular injection of hypertonic saline solution (1 mL, 6%) in both vastus medialis and vastus lateralis muscles (0.9% isotonic saline was used as control). The participants stood barefoot in tandem position for 1 min on a force plate. Center of pressure (CoP) was recorded before and immediately after injections, while performing two cognitive tasks: (i) counting forwards by adding one; (ii) counting backwards by subtracting three. CoP variables-total area of displacement, velocity in anterior-posterior (AP-velocity) and medial-lateral (ML-velocity) directions, and CoP sample entropy in anterior-posterior and medial-lateral directions were displayed as the difference between the values obtained after and before each injection and compared between tasks and injections.CoP total area ( - 84.5 ± 145.5 vs. 28.9 ± 78.5 cmPain interfered with postural stability according to the type of cognitive task performed, suggesting that pain may occupy cognitive resources, potentially resulting in poorer balance performance.

This study compared lower limb external rotation kinematic patterns during sautes in first position in beginners and experienced ballet dancers with various training backgrounds. The ability to attain a perfect turnout is traditionally thought to be a fundamental aspect of classical ballet, and turnout is identified in the literature as one of the leading causes of dance-related injuries and technical limitations among dancers. Twenty-eight ballet dancers of different technical levels and methods (three groups) were assessed. Coefficients of variation (CV), range of motion (ROM), and mean external rotation angles of hip, knee, and ankle in first position saute were calculated. Differences among groups were tested with ANOVAs (Tukey's post hoc; p < 0.05). The hip mean external rotation values found during the jump were different between both experienced groups from different training backgrounds (p = 0.02). The inexperienced group presented a significantly greater hip external rotation CV compared to the experienced groups (p ≤ 0.001). There were no differences between groups for values of external rotation at the knee and ankle. It is concluded that higher technical level dancers produce lower variability of hip external rotation while performing saute in first position. Ballet training background also seems to influence the hip external rotation pattern. Moreover, the knee contributes decisively to turnout composition, not only the hip, as expected.

Buscamos descrever e comparar a cinemática angular de joelho e tornozelo e os padrões de atividade muscular de membro inferior de 3 formas de execução do "footwork" do Método Pilates Posição Arco (PA), Posição Calcanhar (PC) e Posição em V (PV). Vinte e cinco adultos praticantes de Pilates executaram as 3 formas do footwork. Durante as fases de flexão e extensão de joelhos, foram calculadas as integrais dos envoltórios lineares do sinal EMG de vasto medial (VM), bí­ceps femoral (BF), gastrocnêmio lateral (GL), tibial anterior (TA) e fibular longo (FL); os í­ndices de co-contração BF/VM e TA/GL; e a variação angular de joelho e tornozelo. Observamos menores amplitudes de movimento de tornozelo na PC em relação às demais posições. O BF ativou significativamente menos na PV em relação í PA durante a fase de extensão e flexão em relação aos outros dois padrões. A ativação de VM foi menor em PV em relação í PC. A co-contração de BF/VM foi significativamente menor em PV durante a fase de flexão. A PC gerou atividade significativamente maior de TA em relação aos outros padrões na fase de extensão e de flexão e maior atividade de FL e GL na fase de flexão. Todos os padrões permitem a ativação de agonistas e antagonistas de joelho simultaneamente, possibilitando, por meio dessa co-contração, uma melhor estabilização dessa articulação, muito embora na posição em V haja menor co-contração de VM e BF. A PC parece ser a melhor alternativa em um tratamento de fortalecimento e estabilização de tornozelo.Palavras-chave: eletromiografia, joelho, tornozelo, Pilates, exercí­cio.

BACKGROUND: The risk factors for the development of plantar fasciitis (PF) have been associated with the medial longitudinal arch (MLA), rearfoot alignment and calcaneal overload. However, the relationships between the biomechanical variables have yet to be determined. OBJECTIVE: The goal of this study was to investigate the relationships between the MLA, rearfoot alignment, and dynamic plantar loads in runners with unilateral PF in acute and chronic phases. METHOD: Cross-sectional study which thirty-five runners with unilateral PF were evaluated: 20 in the acute phase (with pain) and 15 with previous chronic PF (without pain). The MLA index and rearfoot alignment were calculated using digital images. The contact area, maximum force, peak pressure, and force-time integral over three plantar areas were acquired with Pedar X insoles while running at 12 km/h, and the loading rates were calculated from the vertical forces. RESULTS: The multiple regression analyses indicated that both the force-time integral (R2=0.15 for acute phase PF; R2=0.17 for chronic PF) and maximum force (R2=0.35 for chronic PF) over the forefoot were predicted by an elevated MLA index. The rearfoot valgus alignment predicted the maximum force over the rearfoot in both PF groups: acute (R2=0.18) and chronic (R2=0.45). The rearfoot valgus alignment also predicted higher loading rates in the PF groups: acute (R2=0.19) and chronic (R2=0.40). CONCLUSION: The MLA index and the rearfoot alignment were good predictors of plantar loads over the forefoot and rearfoot areas in runners with PF. However, rearfoot valgus was demonstrated to be an important clinical measure, since it was able to predict the maximum force and both loading rates over the rearfoot.

Diabetic polyneuropathy is an insidious and long-term complication of this disease. Synergistic treatments and preventive actions are crucial because there are no clear boundaries for determining when health professionals should intervene or what intervention would best avoid the consequences of neuropathy. Until now, most therapies to any diabetic individual were applied only after the patient's limb was ulcerated or amputated. The loss of muscle and joint functions is recognized as the main cause of plantar overloading. However, if foot and ankle exercises are performed following the early diagnosis of diabetes, they can enable the patient to maintain sufficient residual function to interact with the environment. This article summarizes the current knowledge about the musculoskeletal deficits and biomechanical alterations caused by neuropathy. It also describes the potential benefits of foot and ankle exercises for any diabetic patient that is not undergoing the plantar ulcer healing process. We concentrate on the prevention of the long-term deficits of neuropathy. We also discuss the main strategies and protocols of therapeutic exercises for joints and muscles with deficits, which are applicable to all diabetic patients with mild to moderate neuropathy. We describe further efforts in exploiting the applicability of assistive technologies to improve the adherence to an exercise program. Following the contemporary trends towards self-monitoring and self-care, we developed a software to monitor and promote personalized exercises with the aim of improving autonomous performance in daily living tasks. Initiatives to prevent the complications of functional diabetes are highly recommended before it is too late for the patient and there is no longer an opportunity to reverse the tragic consequences of neuropathy progression.

Prevention of foot ulcers in patients with diabetes is extremely important to help reduce the enormous burden on both patient and health resources. A comprehensive analysis of reported interventions is not currently available, but is needed to better inform caregivers about effective prevention. The aim of this systematic review is to investigate the effectiveness of interventions to prevent first and recurrent foot ulcers in persons with diabetes who are at-risk for ulceration. The available medical scientific literature in PubMed, EMBASE, CINAHL, and the Cochrane database was searched for original research studies on preventative interventions. Both controlled and non-controlled studies were selected. Data from controlled studies were assessed for methodological quality by two independent reviewers, and extracted and presented in evidence and risk of bias tables. From the identified records, a total of 30 controlled studies (of which 19 RCTs) and another 44 non-controlled studies were assessed and described. Few controlled studies, of generally low to moderate quality, were identified on the prevention of a first foot ulcer. For the prevention of recurrent plantar foot ulcers, multiple RCTs with low risk of bias show the benefit for the use of daily foot skin temperature measurements and consequent preventative actions, as well as for therapeutic footwear that demonstrates to relieve plantar pressure and that is worn by the patient. To prevent recurrence, some evidence exists for integrated foot care when it includes a combination of professional foot treatment, therapeutic footwear and patient education; for just a single session of patient education, no evidence exists. Surgical interventions can be effective in selected patients, but the evidence base is small. The evidence base to support the use of specific self-management and footwear interventions for the prevention of recurrent plantar foot ulcers is quite strong, but is small for the use of other, sometimes widely applied, interventions, and is practically non-existent for the prevention of a first foot ulcer and non-plantar foot ulcer. More controlled studies of high quality are needed in these areas.

Efforts have been made to retard the progressive debilitating pain and joint dysfunction in patients with knee osteoarthritis. We aimed to evaluate the therapeutic effect of a low-cost minimalist footwear on pain, function, clinical and gait-biomechanical aspects of elderly women with knee osteoarthritis.Throughout a randomized, parallel and controlled clinical trial, fifty-six patients with medial knee osteoarthritis were randomly allocated to an intervention (n=28) or control group (n=28), and assessed at baseline and after three and six months. The intervention involved wearing Moleca(®) footwear for at least 6h/day, 7 days/week, over 6 months. The pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index was the primary outcome. The secondary outcomes were the other subscales, Lequesne score, distance walked in 6 min, knee oedema and effusion, knee adduction moment and paracetamol intake. Intention-to-treat analysis was performed using two-way casewise ANOVA (.05) and Cohen's d coefficient.Intervention group showed improvement in pain (effect size: 1.41, p.001), function (effect size: 1.22, p=.001), stiffness (effect size: 0.76, p=.001), Lequesne score (effect size: 1.07, p.001), and reduction by 21.8% in the knee adduction moment impulse (p=.017) during gait wearing Moleca(®). The analgesic intake was lower in the intervention group.The long-term use of Moleca(®) footwear relieves pain, improves self-reported function, reduces the knee loading while wearing Moleca(®), refrains the increase of analgesic intake in elderly women with knee osteoarthritis and can be considered as a conservative mechanical treatment option. ClinicalTrials.gov (NCT01342458).

Skin-markers based multi-segment models are growing in popularity to assess foot joint kinematics in different motor tasks. However, scarce is the current knowledge of the effect of high-energy motor tasks, such as running, on the repeatability of these measurements. This study aimed at assessing and comparing the inter-trial, inter-session, and inter-examiner repeatability of skin-markers based foot kinematic measures in walking and running in healthy adults. The repeatability of 24 kinematic measures from an established multi-segment foot model were assessed in two volunteers during multiple barefoot walking and running trials by four examiners in three sessions. Statistical Parametric Mapping (1D-SPM) analysis was performed to assess the degree of shape-similarity between patterns of kinematic measurements. The average inter-trial variability across measurements (deg) was 1.0 ± 0.3 and 0.8 ± 0.3, the inter-session was 3.9 ± 1.4 and 4.4 ± 1.5, and the inter-examiner was 5.4 ± 2.3 and 5.7 ± 2.2, respectively in walking and running. Inter-session variability was generally similar between the two motor tasks, but significantly larger in running for two kinematic measures (p 0.01). Inter-examiner variability was generally larger than inter-trial and inter-session variability. While no significant differences in frame-by-frame offset variability was detected in foot kinematics between walking and running, 1D-SPM revealed that the shape of kinematic measurements was significantly affected by the motor task, with running being less repeatable than walking. Although confirmation on a larger population and with different kinematic protocols should be sought, attention should be paid in the interpretation of skin-markers based kinematics in running across sessions or involving multiple examiners.

Studies have shown the short- and long-term effects of wearing minimalist footwear in reducing knee loads in patients with knee osteoarthritis (OA). This study aimed to investigate the mechanisms underpinning the reduction in external knee adduction moment (EKAM) in older adult women who wore this type of footwear through a randomized controlled trial. Fifty-six participants with medial compartment knee OA were equally allocated to either an intervention group (IG) that wore minimalist footwear (Moleca®) or to a control group (CG) that continued regular clinical treatment for OA for six months. The influence of lower limb joint kinematics and joint frontal moments, center of pressure displacement, and foot progression angle in predicting the reduction of EKAM were assessed after a six-month intervention. Surprisingly, none of the seven independent variables predicted the first peak EKAM in the multiple regression model for the IG. For the CG, the increase of one unit in the first peak of the hip adduction moment resulted in a 1.01 units increase in the first peak EKAM. Additionally, a one-unit reduction in the ankle eversion angle resulted in an increase of 0.16 units in the percent change in the first peak EKAM. Thus, wearing the Moleca® shoe for six months helped the participants keep a natural gait pattern without increasing the hip moment or the ankle inversion angle compared to the women who did not wear the Moleca® footwear. ClinicalTrials.gov (NCT01342458).

A well-functioning pelvic floor muscle plays an important role in maintaining urinary continence. The aim of this study was to describe and compare the intravaginal pressure profile using a multisensor device along the vaginal length in women with and without urinary incontinence (UI), while performing pelvic floor muscle tasks. Fifty-four adult pre-menopausal women (31 continent and 23 incontinent) participated in this cross-sectional observational cohort study. The intravaginal pressure profile was assessed at rest, during maximum and sustained pelvic floor muscle contractions, using the Pliance® multisensor device. Between-group comparisons were performed considering the overall pressure and the pressure profile of 10-subregions along the vaginal length. In the overall pressure assessment, women with UI presented lower pressures at rest, similar pressures during maximum contraction and lower capacity to maintain pressure during sustained contraction compared to those in the continent group. The pressure profile assessment showed between-group differences that were consistent throughout tasks, with the incontinent group presenting lower pressures than the continent group, specifically in the mid-vaginal length, around 3-4 cm from the vaginal opening. We observed consistent deficits in pressure generation in incontinent compared to continent women, precisely in the region of the pelvic floor muscles. With this protocol and novel instrument, we obtained a reliable and consistent intravaginal pressure profile of continent and incontinent women. This approach could assist clinicians in the assessment of pelvic floor muscle function and foster a better understanding of the urinary incontinence mechanism.

Background Pelvic floor pressure distribution profiles, obtained by a novel instrumented non-deformable probe, were used as the input to a feature extraction, selection, and classification approach to test their potential for an automatic diagnostic system for objective female urinary incontinence assessment. We tested the performance of different feature selection approaches and different classifiers, as well as sought to establish the group of features that provides the greatest discrimination capability between continent and incontinent women. Methods The available data for evaluation consisted of intravaginal spatiotemporal pressure profiles acquired from 24 continent and 24 incontinent women while performing four pelvic floor maneuvers: the maximum contraction maneuver, Valsalva maneuver, endurance maneuver, and wave maneuver. Feature extraction was guided by previous studies on the characterization of pressure profiles in the vaginal canal, where the extracted features were tested concerning their repeatability. Feature selection was achieved through a combination of a ranking method and a complete non-exhaustive subset search algorithm: branch and bound and recursive feature elimination. Three classifiers were tested: k-nearest neighbors (k-NN), support vector machine, and logistic regression. Results Of the classifiers employed, there was not one that outperformed the others; however, k-NN presented statistical inferiority in one of the maneuvers. The best result was obtained through the application of recursive feature elimination on the features extracted from all the maneuvers, resulting in 77.1% test accuracy, 74.1% precision, and 83.3 recall, using SVM. Moreover, the best feature subset, obtained by observing the selection frequency of every single feature during the application of branch and bound, was directly employed on the classification, thus reaching 95.8% accuracy. Although not at the level required by an automatic system, the results show the potential use of pelvic floor pressure distribution profiles data and provide insights into the pelvic floor functioning aspects that contribute to urinary incontinence.

Introduction: This study evaluates the complexity of force and surface electromyography (sEMG) during knee extension and flexion at low-level isometric contractions in individuals with different degrees of diabetic peripheral neuropathy (DPN). Methods: Ten control and 38 diabetic participants performed isometric contractions at 10%, 20%, and 30% of maximal voluntary contraction. Knee force and multichannel sEMG from vastus lateralis (VL) and biceps femoris were acquired. The SD of force and sample entropy (SaEn) of both force and sEMG were computed. Results: Participants with moderate DPN demonstrated high force-SD and low force-SaEn. Severely affected participants showed low SaEn in VL at all force levels. Discussion: DPN affects the complexity of the neuromuscular system at the knee for the extension task during low-level isometric contractions, with participants in the later stages of the disease (moderate and severe) demonstrating most of the changes. Muscle Nerve 57: 112–121, 2018.

Plantar pressure is critical in the onset of neuropathic foot ulcers. However, risk classifications do not consider it as a stratification parameter. Whether plantar pressure distribution affects ulcer-risk was investigated. Patients from a research study (n. 134) and from a clinical environment (n. 83) were classified into ulcer-risk groups according to the International Working Group on the Diabetic Foot guidelines. Pressure distribution was acquired during gait (Pedar-X System), and assessed for hindfoot, midfoot, forefoot and toes (1way- and 2way-ANOVAs, p0.05). Pressure distribution changed with polyneuropathy even in the low-risk groups: median p = 0.048 (0.001-0.223). Risk classification correlated poorly with pressure distribution: median p = 0.686 (0.374-0.828). BMI, age and walking speed influenced most parameters and rendered the studies almost impossible to compare (2-way ANOVA factor A0.05). Pressure-time integral, the only comparable parameter between the two studies, may increase the predictive capacity of ulcer-risk stratification models.

Background Muscle force estimation could advance the comprehension of the neuromuscular strategies that diabetic patients adopt to preserve walking ability, which guarantees their independence as they deal with their neural and muscular impairments due to diabetes and neuropathy. In this study, the lower limb’s muscle force distribution during gait was estimated and compared in diabetic patients with and without polyneuropathy. Methods Thirty individuals were evaluated in a cross-sectional study, equally divided among controls (CG) and diabetic patients with (DNG) and without (DG) polyneuropathy. The acquired ground reaction forces and kinematic data were used as input variables for a scaled musculoskeletal model in the OpenSim software. The maximum isometric force of the ankle extensors and flexors was reduced in the model of DNG by 30% and 20%, respectively. The muscle force was calculated using static optimization, and peak forces were compared among groups (flexors and extensors of hip, knee, and ankle; ankle evertors; and hip abductors) using MANOVAs, followed by univariate ANOVAs and Newman-Keuls post-hoc tests (p < 0.05). Results From the middle to late stance phase, DG showed a lower soleus muscle peak force compared to the CG (p=0.024) and the DNG showed lower forces in the gastrocnemius medialis compared to the DG (p=0.037). At the terminal swing phase, the semitendinosus and semimembranosus peak forces showed lower values in the DG compared to the CG and DNG. At the late stance, the DNG showed a higher peak force in the biceps short head, semimembranosus, and semitendinosus compared to the CG and DG. Conclusion Peak forces of ankle (flexors, extensors, and evertors), knee (flexors and extensors), and hip abductors distinguished DNG from DG, and both of those from CG. Both diabetic groups showed alterations in the force production of the ankle extensors with reductions in the forces of soleus (DG) and gastrocnemius medialis (DNG) seen in both diabetic groups, but only DNG showed an increase in the hamstrings (knee flexor) at push-off. A therapeutic approach focused on preserving the functionality of the knee muscles is a promising strategy, even if the ankle dorsiflexors and plantarflexors are included in the resistance training. Electronic supplementary material The online version of this article (10.1186/s12984-017-0327-x) contains supplementary material, which is available to authorized users.

Objectives To investigate the relationships between the perception of comfort and biomechanical parameters (plantar pressure and ground reaction force) during running with four different types of cushioning technology in running shoes. Design Randomized repeated measures. Methods Twenty-two men, recreational runners (18–45 years) ran 12 km/h with running shoes with four different cushioning systems. Outcome measures included nine items related to perception of comfort and 12 biomechanical measures related to the ground reaction forces and plantar pressures. Repeated measure ANOVAs, Pearson correlation coefficients, and step-wise multiple regression analyses were employed (p ≤ 0.05). Results No significant correlations were found between the perception of comfort and the biomechanical parameters for the four types of investigated shoes. Regression analysis revealed that 56% of the perceived general comfort can be explained by the variables push-off rate and pressure integral over the forefoot (p = 0.015) and that 33% of the perception of comfort over the forefoot can be explained by second peak force and push-off rate (p = 0.016). Conclusions The results did not demonstrate significant relationships between the perception of comfort and the biomechanical parameters for the three types of shoes investigated (Gel, Air, and ethylene-vinyl acetate). Only the shoe with Adiprene+ technology had its general comfort and cushioning perception predicted by the loads over the forefoot. Thus, in general, one cannot predict the perception of comfort of a running shoe through impact and plantar pressure received.

Pelvic floor muscle (PFM) force and coordination are related to urinary incontinence severity and to sexual satisfaction. Health professionals frequently combine classic PFM exercises with hip adduction/abduction contraction to treat these disorders, but the real benefits of this practice are still unknown. Based on a theoretical anatomy approach whereby the levator ani muscle is inserted into the obturator internus myofascia and in which force generated by hip movements should increase the contraction quality of PFMs, our aim was to investigate the effects of isometric hip adduction and abduction on PFM force generation. Twenty healthy, nulliparous women were evaluated using two strain-gauge dynamometers (one cylinder-like inside the vaginal cavity, and the other measuring hip adduction/abduction forces around both thighs) while performing three different tasks: (a) isolated PFM contraction; (b) PFM contraction combined with hip adduction (30% and 50% maximum hip force); and (c) PFM contraction combined with hip abduction (30% and 50% maximum hip force). Data were sampled at 100Hz and subtracted from the offset if existent. We calculated a gradient between the isolated PFM contraction and each hip condition (Δ Adduction and Δ Abduction) for all variables: Maximum force (N), instant of maximum-force occurrence (s), mean force in an 8-second window (N), and PFM force loss (N.s). We compared both conditions gradients in 30% and 50% by paired t-tests. All variables did not differ between hip conditions both in 30% and 50% of maximum hip force (p>.05). PFM contraction combined with isometric hip abduction did not increase vaginal force in healthy and nulliparous women compared to PFM contraction combined with isometric hip adduction. Therefore, so far, the use of hip adduction or abduction in PFM training and treatments are not justified for improving PFM strength and endurance.

Diabetic neuropathic individuals present massive muscle strength reduction at the ankle plantar- and dorsiflexors and increased joint stiffness. Our aim is to investigate the adaptation strategies to these musculoskeletal alterations during walking by means of predictive simulations. We used a seven segment planar musculoskeletal model actuated by eight Hill-type muscles in each leg. The effect of all passive tissue in muscles and other joint structures was modeled by net passive joint moment curves. The predictive simulations were generated by solving an optimal control problem that minimized a cost function, including effort and tracking terms, using direct collocation and a commercial optimal control package. We simulate four conditions to represent the weakening of the distal muscles triceps sural (TS) and tibialis anterior (TA), and five conditions to represent the effect of increasing nonlinear ankle stiffness in flexion. The weakening of the distal muscles leads to a delayed action of the TS and a progressive decrease of the gastrocnemius peak force in the push-off phase. This distal deficit is compensated by a larger hip flexion moment resulting from an increase in the iliopsoas muscle force in this phase, known as the hip strategy. The adaptation mechanisms observed in response to an increase in ankle stiffness include the hip strategy and the exploitation of the passive joint structures as springs, which store energy during midstance and release it during push-off, reducing TS force and power in this phase and leading to a consistent decrease in the overall muscle force levels.

BackgroundResilience of midsole material and the upper structure of the shoe are conceptual characteristics that can interfere in running biomechanics patterns. Artificial intelligence techniques can capture features from the entire waveform, adding new perspective for biomechanical analysis. This study tested the influence of shoe midsole resilience and upper structure on running kinematics and kinetics of non-professional runners by using feature selection, information gain, and artificial neural network analysis.MethodsTwenty-seven experienced male runners (63 ± 44 km/week run) ran in four-shoe design that combined two resilience-cushioning materials (low and high) and two uppers (minimalist and structured). Kinematic data was acquired by six infrared cameras at 300 Hz, and ground reaction forces were acquired by two force plates at 1,200 Hz. We conducted a Machine Learning analysis to identify features from the complete kinematic and kinetic time series and from 42 discrete variables that had better discriminate the four shoes studied. For that analysis, we built an input data matrix of dimensions 1,080 (10 trials × 4 shoes × 27 subjects) × 1,254 (3 joints × 3 planes of movement × 101 data points + 3 vectors forces × 101 data points + 42 discrete calculated kinetic and kinematic features).ResultsThe applied feature selection by information gain and artificial neural networks successfully differentiated the two resilience materials using 200(16%) biomechanical variables with an accuracy of 84.8% by detecting alterations of running biomechanics, and the two upper structures with an accuracy of 93.9%.DiscussionThe discrimination of midsole resilience resulted in lower accuracy levels than did the discrimination of the shoe uppers. In both cases, the ground reaction forces were among the 25 most relevant features. The resilience of the cushioning material caused significant effects on initial heel impact, while the effects of different uppers were distributed along the stance phase of running. Biomechanical changes due to shoe midsole resilience seemed to be subject-dependent, while those due to upper structure seemed to be subject-independent.

Introduction During rowing, foot positioning on the foot stretcher is critical to optimise muscle force transmission and boat propulsion. Following the beneficial effects of textured insoles on gait and balance, this study aims at investigating whether passive stimulation of foot mechanoreceptors induced by these insoles may contribute to improving foot loading pattern and symmetry during indoor rowing. Methods Eleven elite rowers were assessed during controlled training on a standard rowing machine while wearing control, low-density or high-density textured insoles. Plantar pressure and knee and trunk kinematics were measured; performance data were recorded from the machine. Insole effect on kinematic parameters, peak and average values of foot force, contact area and position of centre of pressure was assessed with ANOVA and Bonferroni correction for pair-wise comparisons. Results A main effect was observed for force and contact area, with the high-density insoles providing greatest values (P0.190), even though symmetry was higher with high-density insoles. Kinematics (P = 0.800) and rowing performance were not affected by insole type; a consistent though not statistically significant increase in mean travelled distance was observed for denser insoles (P>0.21). Conclusion The high-density textured insoles affected foot loading distribution during indoor rowing. Rowers applied greater foot force and over a greater foot stretcher area with the high-density than the low-density and control insoles. These findings and the methodology applied may be relevant for the understanding and monitoring of rowing performance.

BACKGROUND: This study evaluated the structure and amount of variability of surface electromyography (sEMG) patterns and ankle force data during low-level isometric contractions in diabetic subjects with different degrees of neuropathy.METHODS: We assessed 10 control subjects and 38 diabetic patients, classified as absent, mild, moderate, or severe neuropathy, by a fuzzy system based on clinical variables. Multichannel sEMG (64-electrode matrix) of tibialis anterior and gastrocnemius medialis muscles were acquired during isometric contractions at 10%, 20%, and 30% of the maximum voluntary contraction, and force levels during dorsi- and plantarflexion were recorded. Standard deviation and sample entropy of force signals were calculated and root mean square and sample entropy were calculated from sEMG signals. Differences among groups of force and sEMG variables were verified using a multivariate analysis of variance.FINDINGS: Overall, during dorsiflexion contractions, moderate and severe subjects had higher force standard deviation and moderate subjects had lower force sample entropy. During plantarflexion, moderate subjects had higher force standard deviation and all diabetic subjects had lower entropy. Tibialis anterior presented higher root mean square in absent group and lower entropy in mild subjects. For gastrocnemius medialis, entropy was higher in severe and lower in moderate subjects.INTERPRETATION: Diabetic neuropathy affects the complexity of the neuromuscular system during low-level isometric contractions, reducing the system's capacity to adapt to challenging mechanical demands. The observed patterns of neuromuscular complexity were not associated with disease severity, with the majority of alterations recorded in moderate subject.

International audience; This study compares muscle fiber conduction velocities estimated using surface electromyography during isometric maximal voluntary contraction in different stages of diabetic neuropathy. Eighty-five adults were studied: 16 non-diabetic individuals and 69 diabetic patients classified into four neuropathy stages, defined by a fuzzy expert system: absent (n = 26), mild (n = 21), moderate (n = 11) and severe (n = 11). Average muscle fiber conduction velocities of gastrocnemius medialis, tibialis anterior, vastus lateralis and biceps femoris were assessed using linear array electrodes, and were compared by ANOVA. Conduction velocities were significantly decreased in the moderate neuropathy group for the vastus lateralis compared to other groups (from 18% to 21% decrease), and were also decreased in all diabetic groups for the tibialis anterior (from 15% to 20% from control group). Not only the distal anatomical localization of the muscle affects the conduction velocity, but also the proportion of muscle fiber type, where the tibialis anterior with greater type I fiber proportion is affected earlier while the vastus lateralis with greater type II fiber proportion is affected in later stages of the disease. Generally, the muscles of the lower limb have different responsiveness to the effects of diabetes mellitus and show a reduction in the conduction velocity as neuropathy progresses.

This study compares surface electromyographic activity of the internal oblique, rectus abdominis, multifidus, iliocostalis, anterior deltoids during the pull-up on a lower and on a higher difficulty level. We assessed nine adults with previous experience in Pilates. The root mean square (RMS) values were normalized by maximum isometric contraction for each participant. During the ascent phase, the low spring position showed a significantly higher RMS than the high spring position of 8.9% for deltoid, 17.2% for internal oblique, 22.3% for rectus abdominis, 4.1% for iliocostalis, and 5.6% for multifidus, and in the descent phase, the RMS in the lower spring exceeded significantly the high spring position in 1.6% for the deltoid, 10% for internal oblique, 31.4% for rectus abdominis and 11.4% for iliocostalis. There was no predominance of abdominal muscles over the shoulder muscle in any spring position. The pull-up exercise can be a useful choice for the core and anterior deltoid muscles strengthening. Este estudo compara a atividade eletromiográfica de superfície dos músculos oblíquo interno, reto abdominal, multífidos, iliocostal e deltóide anterior durante o pull-up em dois níveis de dificuldade (mola alta e mola baixa). Foram avaliadas nove adultos com experiência anterior em Pilates. Os valores RMS foram normalizados pela contração isométrica máxima. Durante a fase de subida, a posição de mola baixa mostrou RMS significativamente maiores em relação a alta de 8,9% para deltóide, 17,2% para o oblíquo interno, 22,3% para o reto abdominal, 4,1% para iliocostal, e 5,6% para o multífido, e na fase de descida, em 1,6% para o deltóide, 10% para oblíquo interno, 31,4% para o reto abdominal e 11,4% para o iliocostal. Não houve predomínio dos músculos abdominais sob o músculo do ombro em qualquer posição de mola. O exercício de pull-up pode ser ferramenta útil para o fortalecimento da musculatura do core e do músculo deltóide anterior. Este estudio compara la EMG superficial de los músculos recto del abdomen, oblicuo interno, multifidos, ilio-costal y deltoides anterior durante el ejercicio pull-up en dos niveles de dificultad. Se evaluaron a nueve adultos experimentados en Pilates. Los valores de RMS se normalizaron por la contracción isométrica máxima. Durante la fase de ascenso, la posición baja del resorte mostró valores significativamente majores de RMS que la posición alta de 8,9% para lo deltoides, 17,2% para oblicuo interno, 22,3% para recto abdominal, 4,1% para ilio-costalis, y 5,6% para multifidos. En la fase de descenso, el RMS, en el muelle inferior, excede significativamente la posición alta del resorte en 1,6% para el deltoides, 10% para oblicuo interno, 31,4% para recto abdominal y 11,4% para ilio-costalis. No hubo predominio de los músculos abdominales bajo los deltoides anteriores. Pull-up puede ser una herramienta útil para el trabajo del core y para la fortificación del deltoides anterior.

There have been several research studies on efficient methods for analysis and classification of electromyography (EMG) signals and adoption of wavelet functions, which is a promising approach for determining the spectral distribution of the signal. This study compares distinct time-frequency analysis methods for investigating the EMG activity of the thigh and calf muscles during gait among non-diabetic subjects and diabetic neuropathic patients. It also attempts to verify, by adaptive optimal kernel and discrete wavelet transform, whether there are EMG alterations related to diabetic neuropathy in the lower limb muscles during gait. The results show that diabetics might not keep up with the mechanical demands of walking by changing muscle fibre recruitment strategies, as seen in the control group. Moreover, principal components analysis indicates more alterations in diabetic motor strategies, and we identify that diabetic subjects need other strategies with different muscle energy production and frequencies to carry out their daily activities.

The purpose of this literature review is to evaluate the studies that have investigated static and dynamic biomechanical changes of the lower limbs and gait patterns during pregnancy. Original articles on this subject, published between 1934 and 2012, were considered. In general, pregnant women demonstrated greater hip flexion, more extended knees and less plantar flexion ankles. These changes could explain the gait patterns of pregnant women characterized by increased hip angles, decreased propulsion forces associated with increased durations of stance phase and changes in distributions of the plantar loads with increased loads in the forefoot and decreased ones in the rearfoot. This can lead to arthrokinematic deviations that, with time, contribute to the development of musculoskeletal discomfort. In summary, these findings showed the importance of further longitudinal studies to investigate the relationships between musculoskeletal discomfort in pregnant women in the lower limbs and gait changes observed throughout this period.

BACKGROUND: The progression of diabetes and the challenge of daily tasks may result in changes in biomechanical strategies. Descending stairs is a common task that patients have to deal with, however it still has not been properly studied in this population. OBJECTIVES: We describe and compare the net joint moments and kinematics of the lower limbs in diabetic individuals with and without peripheral neuropathy and healthy controls during stair descent. METHOD: Forty-two adults were assessed: control group (13), diabetic group (14), and neuropathic diabetic group (15). The flexor and extensor net moment peaks and joint angles of the hip, knee, and ankle were described and compared in terms of effect size and ANOVAs (pCONTEXTUALIZAÇÃO: A progressão do Diabetes Mellito e as atividades desafiadoras do dia a dia podem resultar em mudanças da estratégia biomecânica adotada. Descer escadas é uma tarefa comum do dia a dia, vivenciada pelos pacientes, mas ainda não foi satisfatoriamente estudada nessa população. OBJECTIVOS: Descrever e comparar os momentos articulares e a cinemática de membros inferiores em indivíduos diabéticos com e sem a neuropatia periférica e controles saudáveis durante o descer escadas. MÉTODO: Quarenta e dois adultos foram avaliados: grupo controle (13), grupo diabético (15) e grupo de diabéticos neuropatas (14). Os picos flexores e extensores dos momentos articulares e os ângulos articulares de quadril, joelho e tornozelo foram comparados e descritos por análise do tamanho do efeito e ANOVAs (p

Background Overall performance, particularly in a very popular sports activity such as running, is typically influenced by the status of the musculoskeletal system and the level of training and conditioning of the biological structures. Any change in the musculoskeletal system’s biomechanics, especially in the feet and ankles, will strongly influence the biomechanics of runners, possibly predisposing them to injuries. A thorough understanding of the effects of a therapeutic approach focused on feet biomechanics, on strength and functionality of lower limb muscles will contribute to the adoption of more effective therapeutic and preventive strategies for runners. Methods/Design A randomized, prospective controlled and parallel trial with blind assessment is designed to study the effects of a "ground-up" therapeutic approach focused on the foot-ankle complex as it relates to the incidence of running-related injuries in the lower limbs. One hundred and eleven (111) healthy long-distance runners will be randomly assigned to either a control (CG) or intervention (IG) group. IG runners will participate in a therapeutic exercise protocol for the foot-ankle for 8 weeks, with 1 directly supervised session and 3 remotely supervised sessions per week. After the 8-week period, IG runners will keep exercising for the remaining 10 months of the study, supervised only by web-enabled software three times a week. At baseline, 2 months, 4 months and 12 months, all runners will be assessed for running-related injuries (primary outcome), time for the occurrence of the first injury, foot health and functionality, muscle trophism, intrinsic foot muscle strength, dynamic foot arch strain and lower-limb biomechanics during walking and running (secondary outcomes). Discussion This is the first randomized clinical trial protocol to assess the effect of an exercise protocol that was designed specifically for the foot-and-ankle complex on running-related injuries to the lower limbs of long-distance runners. We intend to show that the proposed protocol is an innovative and effective approach to decreasing the incidence of injuries. We also expect a lengthening in the time of occurrence of the first injury, an improvement in foot function, an increase in foot muscle mass and strength and beneficial biomechanical changes while running and walking after a year of exercising. Trial registration Clinicaltrials.gov Identifier NCT02306148 (November 28, 2014) under the name “Effects of Foot Strengthening on the Prevalence of Injuries in Long Distance Runners”. Committee of Ethics in Research of the School of Medicine of the University of Sao Paulo (18/03/2015, Protocol # 031/15). Electronic supplementary material The online version of this article (doi:10.1186/s12891-016-1016-9) contains supplementary material, which is available to authorized users.

We investigated the muscle fiber conduction velocity (MFCV) during gait phases of the lower limb muscles in individuals with various degrees of diabetic peripheral neuropathy (DPN). Forty-five patients were classified into severity degrees of DPN by a fuzzy model. The stages were absent (n=11), mild (n=14), moderate (n=11) and severe (n=9), with 10 matched healthy controls. While walking, all subjects had their sEMG (4 linear electrode arrays) recorded for tibialis anterior (TA), gastrocnemius medialis (GM), vastus lateralis (VL) and biceps femoris (BF). MFCV was calculated using a maximum likelihood algorithm with 30ms standard deviation Gaussian windows. In general, individuals in the earlier stages of DPN showed lower MFCV of TA, GM and BF, whilst individuals with severe DPN presented higher MFCV of the same muscles. We observed that mild patients already showed lower MFCV of TA at early stance and swing, and lower MFCV of BF at swing. All diabetic groups showed a markedly reduction in MFCV of VL, irrespective of DPN. Severe patients presented higher MFCV mainly in distal muscles, TA at early and swing phases and GM at propulsion and midstance. The absent group already showed MFCV of VL and GM reductions at the propulsion phase and of VL at early stance. Although MFCV changes were not as progressive as the DPN was, we clearly distinguished diabetic patients from controls, and severe patients from all others.

The practice of running has consistently increased worldwide, and with it, related lower limb injuries. The type of running surface has been associated with running injury etiology, in addition other factors, such as the relationship between the amount and intensity of training. There is still controversy in the literature regarding the biomechanical effects of different types of running surfaces on foot-floor interaction. The aim of this study was to investigate the influence of running on asphalt, concrete, natural grass, and rubber on in-shoe pressure patterns in adult recreational runners. Forty-seven adult recreational runners ran twice for 40 m on all four different surfaces at 12 ± 5% km · h(-1). Peak pressure, pressure-time integral, and contact time were recorded by Pedar X insoles. Asphalt and concrete were similar for all plantar variables and pressure zones. Running on grass produced peak pressures 9.3% to 16.6% lower (P0.001) than the other surfaces in the rearfoot and 4.7% to 12.3% (P0.05) lower in the forefoot. The contact time on rubber was greater than on concrete for the rearfoot and midfoot. The behaviour of rubber was similar to that obtained for the rigid surfaces - concrete and asphalt - possibly because of its time of usage (five years). Running on natural grass attenuates in-shoe plantar pressures in recreational runners. If a runner controls the amount and intensity of practice, running on grass may reduce the total stress on the musculoskeletal system compared with the total musculoskeletal stress when running on more rigid surfaces, such as asphalt and concrete.

Unstable shoes have been designed to promote "natural instability" and during walking they should simulate barefoot gait, enhancing muscle activity and, thus, attributing an advantage over regular tennis shoes. Recent studies showed that, after special training on the appropriate walking pattern, the use of the Masai Barefoot Technology (MBT) shoe increases muscle activation during walking. Our study presents a comparison of muscle activity as well as horizontal and vertical forces during gait with the MBT, a standard tennis shoe and barefoot walking of healthy individuals without previous training. These variables were compared in 25 female subjects and gait conditions were compared using ANOVA repeated measures (effect size:0.25). Walking with the MBT shoe in this non-instructed condition produced higher vertical forces (first vertical peak and weight acceptance rate) than walking with a standard shoe or walking barefoot, which suggests an increase in the loads received by the musculoskeletal system, especially at heel strike. Walking with the MBT shoe did not increase muscle activity when compared to walking with the standard shoe. The barefoot condition was more effective than the MBT shoe at enhancing muscle activation. Therefore, in healthy individuals, no advantage was found in using the MBT over a standard tennis shoe without a special training period. Further studies using the MBT without any instruction over a longer period are needed to evaluate if the higher loads observed in the present study would return to their baseline values after a period of adaptation, and if the muscle activity would increase over time.

OBJECTIVE: This study proposes a new approach that considers uncertainty in predicting and quantifying the presence and severity of diabetic peripheral neuropathy. METHODS: A rule-based fuzzy expert system was designed by four experts in diabetic neuropathy. The model variables were used to classify neuropathy in diabetic patients, defining it as mild, moderate, or severe. System performance was evaluated by means of the Kappa agreement measure, comparing the results of the model with those generated by the experts in an assessment of 50 patients. Accuracy was evaluated by an ROC curve analysis obtained based on 50 other cases; the results of those clinical assessments were considered to be the gold standard. RESULTS: According to the Kappa analysis, the model was in moderate agreement with expert opinions. The ROC analysis (evaluation of accuracy) determined an area under the curve equal to 0.91, demonstrating very good consistency in classifying patients with diabetic neuropathy. CONCLUSION: The model efficiently classified diabetic patients with different degrees of neuropathy severity. In addition, the model provides a way to quantify diabetic neuropathy severity and allows a more accurate patient condition assessment.

to the editor: We read with interest the Physiology in Medicine review by Allen et al. ([1][1]) on the role of the neuromuscular consequences of diabetic neuropathy (DPN). Three main points in the review deserve attention and should be further discussed. First, DPN-related motor unit (MU) loss is

Introduction: Changes in gait cadence caused by challenging situations in daily life might induce higher demand for strength and propulsion in diabetic neuropathic (DN) sub- jects. Methods: Forty-six subjects (healthy and DN) walked at two cadences (self-selected and 25% higher). Kinematic and electromyographic data were obtained from lower limbs and compared across the gait cycle. Results: DN subjects showed a delayed peak in plantarflexor activity along the whole cycle (irre- spective of cadence) compared with healthy subjects. However, during the imposed cadence, DN individuals showed reduced ankle range of motion along the entire cycle compared with the self-selected condition and healthy individuals walking at both cadences (P ¼ 0.002). Conclusions: These findings suggest that when diabetic individuals face a new challenging situation that induces a higher demand for muscle strength and propul- sion, the necessary range of motion and neuromuscular control around distal joints are insufficient. Muscle Nerve 44: 258-268, 2011 The biomechanical pattern of gait is highly repeti- tive, cyclic, and has low variation across steps as well as across days. 1 This feature allows us to use gait analysis as an experimental model to investi- gate the influence of the environment, such as real-life challenges and perturbations, and biology, such as neuromuscular diseases. These two factors might impair both the coordinated harmonic action of the lower limbs and the neuromuscular strategies adopted for the control of locomotion. Diabetic neuropathy (DN) impairs both the soma- tosensory and motor control systems, 2,3 and affects the amount and quality of the sensory information that is essential for the complexity involved in gait generation and control. 4 The regularity of normal gait allows for the establishment of basic biome- chanical criteria to distinguish between normal and pathologic patterns of movement, such as gait patterns in DN individuals.

INTRODUCTION: In this study we investigate the influence of diabetic neuropathy (DN) on lower limb electromyography (EMG) and kinematics during stair negotiation. METHODS: Forty-six adults (healthy and DN) performed stair ascent and descent tasks. Kinematic and EMG data were assessed unilaterally. RESULTS: DN patients had lower ankle dorsiflexion while ascending and plantarflexion while descending. This reduced dorsiflexion compromises proper ankle and knee positions necessary for an efficient lifting action by the vastus lateralis (VL). The mechanical disadvantage of VL at the beginning of the stance triggered prolonged VL activation at the end of stair ascent. In stair descent, DN patients showed lower tibialis anterior activity in the early phase that can potentially impair the mechanism of impact absorption when the forefoot contacts the step. CONCLUSIONS: Our results reveal an adaptive motor strategy in DN patients to overcome the challenge of stair ascent, which promoted more biomechanical deficits. Language: en

OBJECTIVE: To evaluate and compare rearfoot alignment and medial longitudinal arch index during static postures in runners, with and without symptoms and histories of plantar fasciitis (PF). INTRODUCTION: PF is the third most common injury in runners but, so far, its etiology remains unclear. In the literature, rearfoot misalignment and conformations of the longitudinal plantar arch have been described as risk factors for the development of PF. However, in most of the investigated literature, the results are still controversial, mainly regarding athletic individuals and the effects of pain associated with these injuries. METHODS: Forty-five runners with plantar fasciitis (30 symptomatic and 15 with previous histories of injuries) and 60 controls were evaluated. Pain was assessed by a visual analogue scale. The assessment of rearfoot alignment and the calculations of the arch index were performed by digital photographic images. RESULTS: There were observed similarities between the three groups regarding the misalignments of the rearfoot valgus. The medial longitudinal arches were more elevated in the group with symptoms and histories of PF, compared to the control runners. CONCLUSIONS: Runners with symptoms or histories of PF did not differ in rearfoot valgus misalignments, but showed increases in the longitudinal plantar arch during bipedal static stance, regardless of the presence of pain symptoms.

Recent literature has highlighted that the flexibility of walking barefoot reduces overload in individuals with knee osteoarthritis (OA). As such, the aim of this study was to evaluate the effects of inexpensive, flexible, non-heeled footwear (Moleca) as compared with a modern heeled shoes and walking barefoot on the knee adduction moment (KAM) during gait in elderly women with and without knee OA. The gait of 45 elderly women between 60 and 70 years of age was evaluated. Twenty-one had knee OA graded 2 or 3 according to Kellgren and Lawrence's criteria, and 24 who had no OA comprised the control group (CG). The gait conditions were: barefoot, Moleca, and modern heeled shoes. Three-dimensional kinematics and ground reaction forces were measured to calculate KAM by inverse dynamics. For both groups, the Moleca provided peak KAM and KAM impulse similar to barefoot walking. For the OA group, the Moleca reduced KAM even more as compared to the barefoot condition during midstance. On the other hand, the modern heeled shoes increased this variable in both groups. Inexpensive, flexible, and non-heeled footwear provided loading on the knee joint similar to a barefoot gait and significant overload decreases in elderly women with and without knee OA, compared to modern heeled shoes. During midstance, the Moleca also allowed greater reduction in the knee joint loads as compared to barefoot gait in elderly women with knee OA, with the further advantage of providing external foot protection during gait.

article i nfo Article history: Received 14 May 2010 Accepted 20 August 2010 Background: Plantar fasciitis is the third most frequent injury in runners. Despite its high prevalence, its pathogenesis remains inconclusive. The literature reports overload as the basic mechanism for its development. However, the way that these plantar loads are distributed on the foot surface of runners with plantar fasciitis and the effects of pain on this mechanical factor has not yet been investigated. Therefore, the aim of this study was to evaluate and compare the plantar pressure distributions during running in runners with symptom or history of plantar fasciitis and runners without the disease. Methods: Forty-five recreational runners with plantar fasciitis (30 symptomatic and 15 with previous history of the disease) and 60 runners without plantar fasciitis (control group) were evaluated. Pain was assessed by a visual analogue scale. All runners were evaluated by means of the Pedar system insoles during running forty meters at a speed of 12(5%) km/h, using standard sport footwear. Two-way ANOVAS were employed to investigate the main and interaction effects between groups and plantar areas. Findings: No interaction effects were found for any of the investigated variables: peak pressure (P = 0.61), contact area (P = 0.38), contact time (P = 0.91), and the pressure-time integral (P =0 .50). Interpretation: These findings indicated that the patterns of plantar pressure distribution were not affected in recreational runners with plantar fasciitis when compared to control runners. Pain also did not interfere with the dynamic patterns of the plantar pressure distributions.

BACKGROUND: Patellofemoral Pain Syndrome is one of the most common knee disorders among physically active young women. Despite its high incidence, the multifactorial etiology of this disorder is not fully understood. OBJECTIVES: To investigate the influence of Patellofemoral Pain Syndrome on plantar pressure distribution during the foot rollover process (i.e., the initial heel contact, midstance and propulsion phases) of the gait. MATERIALS AND METHODS: Fifty-seven young adults, including 22 subjects with Patellofemoral Pain Syndrome (30 ± 7 years, 165 ± 9 cm, 63 ± 12 kg) and 35 control subjects (29 ± 7 years, 164 ± 8 cm, 60 ± 11 kg), volunteered for the study. The contact area and peak pressure were evaluated using the Pedar-X system (Novel, Germany) synchronized with ankle sagittal kinematics. RESULTS: Subjects with Patellofemoral Pain Syndrome showed a larger contact area over the medial (p = 0.004) and central (p = 0.002) rearfoot at the initial contact phase and a lower peak pressure over the medial forefoot (p = 0.033) during propulsion when compared with control subjects. CONCLUSIONS: Patellofemoral Pain Syndrome is related to a foot rollover pattern that is medially directed at the rearfoot during initial heel contact and laterally directed at the forefoot during propulsion. These detected alterations in the foot rollover process during gait may be used to develop clinical interventions using insoles, taping and therapeutic exercise to rehabilitate this dysfunction.

Objectives To investigate plantar pressure distribution in individuals with and without Patellofemoral Pain Syndrome during the support phase of stair descent. Design Observational case–control study. Participants 30 young adults with Patellofemoral Pain Syndrome and 44 matched controls. Main outcome measures Contact area, peak pressure and pressure–time integral (Novel Pedar-X system) were evaluated in six plantar areas (medial, central and lateral rearfoot; midfoot; medial and lateral forefoot) during stair descent. Results Contact area was greater in the Patellofemoral Pain Syndrome Group at medial rearfoot ( p = 0.019) and midfoot ( p p Conclusion The pattern of plantar pressure distribution during stair descent in Patellofemoral Pain Syndrome subjects was different from controls. This seems to be related to greater medial rearfoot and midfoot support. Smaller plantar loads found in Patellofemoral Pain Syndrome subjects during stair descent reveal a more cautious motor pattern in a challenging task.