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1.
Nature ; 579(7797): 97-100, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32103182

RESUMO

The stiff human foot enables an efficient push-off when walking or running, and was critical for the evolution of bipedalism1-6. The uniquely arched morphology of the human midfoot is thought to stiffen it5-9, whereas other primates have flat feet that bend severely in the midfoot7,10,11. However, the relationship between midfoot geometry and stiffness remains debated in foot biomechanics12,13, podiatry14,15 and palaeontology4-6. These debates centre on the medial longitudinal arch5,6 and have not considered whether stiffness is affected by the second, transverse tarsal arch of the human foot16. Here we show that the transverse tarsal arch, acting through the inter-metatarsal tissues, is responsible for more than 40% of the longitudinal stiffness of the foot. The underlying principle resembles a floppy currency note that stiffens considerably when it curls transversally. We derive a dimensionless curvature parameter that governs the stiffness contribution of the transverse tarsal arch, demonstrate its predictive power using mechanical models of the foot and find its skeletal correlate in hominin feet. In the foot, the material properties of the inter-metatarsal tissues and the mobility of the metatarsals may additionally influence the longitudinal stiffness of the foot and thus the curvature-stiffness relationship of the transverse tarsal arch. By analysing fossils, we track the evolution of the curvature parameter among extinct hominins and show that a human-like transverse arch was a key step in the evolution of human bipedalism that predates the genus Homo by at least 1.5 million years. This renewed understanding of the foot may improve the clinical treatment of flatfoot disorders, the design of robotic feet and the study of foot function in locomotion.


Assuntos
Evolução Biológica , Fenômenos Biomecânicos , Pé/anatomia & histologia , Pé/fisiologia , Testes de Dureza , Animais , Cadáver , Extinção Biológica , Feminino , Pé/fisiopatologia , Hominidae/anatomia & histologia , Hominidae/fisiologia , Humanos , Pessoa de Meia-Idade , Pan troglodytes/anatomia & histologia , Pan troglodytes/fisiologia , Maleabilidade , Pé Cavo/fisiopatologia
2.
J Physiol Anthropol ; 39(1): 3, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32059744

RESUMO

BACKGROUND: Car accidents due to unexpected forward or backward runaway by older drivers are a serious social problem. Although the cause of these accidents is often attributed to stepping on the accelerator instead of the brake, it is difficult to induce such pedal application errors systematically with usual drive simulators. We developed a simple personal computer system that induces the pedal errors, and investigate the effects of age on the error behaviors. METHODS: The system consisted of a laptop computer and a three-pedal foot mouse. It measured response time, accuracy, and flexibility of pedal operation to visual stimuli. The system displayed two open circles on the computer display, lighting one of the circles in a random order and interval. Subjects were instructed to press the foot pedal with their right foot as quickly as possible when the circle was lit; the ipsilateral pedal to the lit circle in a parallel mode and the contralateral pedal in a cross mode. When the correct pedal was pressed, the light went off immediately, but when the wrong pedal was pressed, the buzzer sounded and the light remained on until the correct pedal was pressed. During a 6-min trial, the mode was switched between parallel and cross every 2 min. During the cross mode, a cross mark appears on the display. The pedal responses were evaluated in 52 subjects divided into young (20-29 years), middle-aged (30-64 years), and older (65-84 years) groups. Additionally, the repeatability of the pedal response characteristic indicators was examined in 14 subjects who performed this test twice. RESULTS: The mean response time was 95 ms (17%) longer in the older group than in the young group. More characteristically, however, the older group showed 2.1 times more frequent pedal errors, fell into long hesitations (response freezing > 3 s) 16 times more often, and took 1.8 times longer period to correct the wrong pedal than the young groups. The indicators of pedal response characteristics showed within-individual repeatability to the extent that can identify the age-dependent changes. CONCLUSIONS: Hesitations and extended error correction time can be associated with increased crash risk due to unexpected runaway by older drivers. The system we have developed may help to uncover and evaluate physiological characteristics related to crash risk in the elderly population.


Assuntos
Envelhecimento/fisiologia , Condução de Veículo , Pé/fisiologia , Tempo de Reação/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Simulação por Computador , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
3.
J Sports Sci ; 38(3): 336-342, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31795818

RESUMO

A decrease in speed when sprinting on the bend compared with the straight has been attributed to kinetic, kinematic and spatiotemporal modifications. Although maximal speed is dependent on an athlete's ability to accelerate, there is limited research investigating the acceleration phase of bend sprinting. This study used a lower limb and trunk marker set with 15 optoelectronic cameras to examine kinematic and spatiotemporal variables of the lower limb during sprinting on the bend and straight. Nine sprinters completed up to six 30 m maximal effort trials in bend (radius 36.5 m, lane one) and straight conditions. An increase in body lateral lean at touchdown resulted in a number of asymmetric kinematic modifications. Whilst the left limb demonstrated a greater peak hip adduction, peak hip internal rotation and peak ankle eversion on the bend compared with the straight, the right limb was characterised by an increase in peak hip abduction. These results demonstrate that kinematic modifications start early in the race and likely accumulate, resulting in greater modifications at maximal speed. It is recommended that strength and conditioning programmes target the hip, ankle and foot in the non-sagittal planes. In addition, sprint training should prioritise specificity by occurring on the bend.


Assuntos
Extremidade Inferior/fisiologia , Corrida/fisiologia , Atletismo/fisiologia , Aceleração , Tornozelo/fisiologia , Fenômenos Biomecânicos , Pé/fisiologia , Quadril/fisiologia , Humanos , Joelho/fisiologia , Postura/fisiologia , Rotação , Estudos de Tempo e Movimento , Adulto Jovem
4.
Sports Biomech ; 19(2): 168-179, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29877754

RESUMO

The aim of this study was to investigate whether changes on foot-stretcher height were associated with characteristics of better rowing performance. Ten male rowers performed a 200 m rowing trial at their racing rate at each of three foot-stretcher heights. A single scull was equipped with an accelerometer to collect boat acceleration, an impeller with embedded magnets to collect boat speed, specially designed gate sensors to collect gate force and angle, and a compact string potentiometer to collect leg drive length. All sensor signals were sampled at 50 Hz. A one-way repeated measures ANOVA showed that raising foot-stretcher position had a significant reduction on total gate angle and leg drive length. However, a raised foot-stretcher position had a deeper negative peak of boat acceleration at the catch, a lower boat fluctuation, a faster leg drive speed, a larger gate force for the port and starboard side separately. This could be attributed to the optimisation of the magnitude and direction of the foot force with a raised foot-stretcher position. Although there was a significant negative influence of a raised foot-stretcher position on two kinematic variables, biomechanical evidence suggested that a raised foot-stretcher position could contribute to the improvement of rowing performance.


Assuntos
Desempenho Atlético/fisiologia , Pé/fisiologia , Navios/instrumentação , Equipamentos Esportivos , Esportes Aquáticos/fisiologia , Aceleração , Adulto , Fenômenos Biomecânicos , Humanos , Perna (Membro)/fisiologia , Masculino , Adulto Jovem
5.
J Sports Sci ; 38(3): 248-255, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726955

RESUMO

Accelerometers are often placed on the tibia to measure segmental accelerations, and external mechanical load during running. However, in applied sport settings it is sometimes preferable to place accelerometers on the dorsal foot to avoid tibial impact injuries. This study aimed to quantify the differences in accelerations measured at the dorsal foot compared with the distal tibia during running. Sixteen recreationally active participants performed a sprint protocol on a non-motorised treadmill. Accelerometers were positioned bilaterally on the medial tibia (TIBLeft and TIBRight), and bilateral dorsal foot surfaces (DORLeft and DORRight). Continuous acceleration signal waveform analysis was performed using one-dimensional statistical parametric mapping (1DSPM). Resultant accelerations were greater for DORLeft than TIBLeft for 60% of the gait cycle (p < 0.001) and greater for DORRight than TIBRight for 50% of the gait cycle (p < 0.003). The larger accelerations at the dorsal foot than the tibia can be explained by movement at the ankle joint, and the placement location relative to the hip. The dorsal foot location can be used to effectively measure accelerations and external mechanical load when it is not feasible to place the accelerometer on the tibia, however results between the two locations should not be compared.


Assuntos
Acelerometria/instrumentação , Monitores de Aptidão Física , Pé/fisiologia , Corrida/fisiologia , Tíbia/fisiologia , Aceleração , Adulto , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , Estudos de Viabilidade , Feminino , Quadril/fisiologia , Humanos , Masculino , Movimento/fisiologia , Percepção/fisiologia , Esforço Físico/fisiologia , Adulto Jovem
6.
Gait Posture ; 75: 22-27, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31590066

RESUMO

BACKGROUND: Kinematic gait analysis employing multi-segment foot models has been mainly conducted in laboratories by means of optical motion capture systems. This type of process requires considerable setup time and is constrained by a limited capture space. A procedure involving the use of multiple inertial measurement units (IMUs) is proposed to overcome these limitations. RESEARCH QUESTION: This study presents a new approach for the estimation of the trajectories of a multi-segment foot model by means of multiple IMUs. METHODS: To test the proposed method, a system consisting of four IMUs attached to the shank, heel, dorsum and toes segments of the foot, was considered. The performance of the proposed method was compared to that of a conventional method using IMUs adopted from the literature. In addition, an optical motion capture system was used as a reference to assess the performance of the implemented methods. RESULTS: Employing the suggested method, all trajectory directions of the shank, heel and dorsum segments, as well as the Z (yaw) direction of the toes segment, have exhibited an error reduction varying between 8% and 55%. However, X (roll) and Y (pitch) direction of the toes segment presented an error increase of 17% and 26%, respectively. The estimation of the vertical displacement, corresponding to the foot clearance, was improved for all segments, resulting in a final mean accuracy and precision of 3.5 ±â€¯2.8 cm, 2.7 ±â€¯2.1 cm, 0.8 ±â€¯0.7 cm and 1.1 ±â€¯0.9 cm for the shank, heel, dorsum and toes segments, respectively. SIGNIFICANCE: It has been demonstrated that as an alternative to tracking each foot segment separately, the fusion of multiple IMU measurements using kinematic equations, considerably improves the estimated trajectories, especially when considering vertical foot displacements. The proposed method could complement the use of smaller and cheaper sensors, while still matching the same performance of other published methods, making the suggested approach very attractive for real life applications.


Assuntos
Acelerometria/instrumentação , Algoritmos , Pé/fisiologia , Marcha/fisiologia , Adulto , Fenômenos Biomecânicos , Desenho de Equipamento , Voluntários Saudáveis , Humanos , Reprodutibilidade dos Testes
7.
Gait Posture ; 75: 46-62, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31593873

RESUMO

BACKGROUND: Centre of pressure (COP), plantar pressure (PP), and plantar-flexion isometric strength (PFisom) are often examined in relation to postural control and gait. RESEARCH QUESTION: Our aim was to systematically review and quality appraise articles addressing the reliability of COP and PP measures in static stance and PFisom measures. METHODS: Three electronic databases (SCOPUS®, SportDISCUS™, and PubMed) were searched and supplemented by a manual search. Peer-reviewed original research on the reliability of COP, PP, and PFisom in healthy adults (≥18 years) was included. Quality appraisal was done according to the updated COnsensus-based Standards for the selection of health Measurement INstruments reliability checklist. Data regarding study characteristics, test protocols, outcome measures, and reliability metrics were extracted. RESULTS: Forty articles met inclusion and were assessed for their methodological quality. Only four articles (10%) obtained uppermost quality scores. From the reviewed studies, the most reliable measures were: COP sway area and path length; PP mean pressure, percentage body weight distribution, and contact area; and PFisom peak torque and force. Although these measures generally exhibited good-to-excellent relative reliability based on correlation coefficients, absolute reliability based on typical errors were not always optimal (variation > 10%). Literature on PP reliability was scarce (n = 2). SIGNIFICANCE: Our findings highlight the need for better quality methodological reliability studies to be undertaken to make stronger inferences about the reliability of COP, PP, and PFisom measures. The most reliable measures based on the current review are: COP sway area and path length; PP mean pressure, percentage of body weight distribution, and contact area; and PFisom peak torque and peak force. These measures are the ones that should be selected preferentially in clinical settings, bearing in mind that their typical errors might be suboptimal despite exhibiting strong relative reliability.


Assuntos
Pé/fisiologia , Marcha/fisiologia , Contração Isométrica/fisiologia , Equilíbrio Postural/fisiologia , Humanos , Pressão , Psicometria/métodos , Reprodutibilidade dos Testes
8.
Gait Posture ; 75: 66-71, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31605898

RESUMO

BACKGROUND: Walking on railroad ballast is a unique challenge for railroad workers and contributes to a large number of falls and slips. However, the characteristics of ground reaction force (GRF) when walking on ballast combined with a cross-slope condition are poorly understood. RESEARCH QUESTION: How does the magnitude and temporal distribution of GRF change during walking on railroad ballast combined with a cross-slope condition? METHODS: Eight experienced railroad workers walked with their self-selected speed on three surfaces (mainline ballast, walking ballast and no ballast) in both a level and cross-slope (7°) condition. The magnitude and time of occurrence of selected key features of the GRF were extracted from the force plate. A two-factor repeated measures ANOVA was used to determine the effect of surface and cross-slope condition. RESULTS: The minimum anteroposterior GRF and the first peak of the normal GRF occurred earlier on mainline ballast and walking ballast than no ballast. The maximum anteroposterior GRF was smaller, but the first peak of the normal GRF was larger on walking ballast compared with no ballast. Additionally, the asymmetrically mediolateral GRFs were observed between upslope limb and downslope limb in the cross-slope condition, which were also significantly different from the level condition. SIGNIFICANCE: Ballast combined with a cross-slope condition posed a higher requirement for dynamic control to prevent downslope slippage and body instability, which could increase the fall risk for railroad workers. Future studies should investigate interventions to improve dynamic balance and reduce foot slippage on ballast.


Assuntos
Pé/fisiologia , Marcha/fisiologia , Caminhada/fisiologia , Acidentes por Quedas/prevenção & controle , Adulto , Fenômenos Biomecânicos , Humanos , Masculino , Ferrovias
9.
Gait Posture ; 75: 149-154, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31683185

RESUMO

BACKGROUND: Gastrocnemius medialis (GM) and lateralis (GL) act at the ankle complex in the sagittal and frontal planes and there is evidence that their actions can be somewhat uncoupled from each other. Some independence of GM and GL from each other could be advantageous, e.g. to stabilise the ankle complex in unstable walking conditions. Given the compartmentalised structure of the Achilles tendon, the sub-tendons of GM and GL may exhibit different elongation during plantarflexion contractions, particularly with the foot in different frontal plane positions. RESEARCH QUESTIONS: METHODS: Sub-tendon elongation was determined from 18 participants during ramped isometric plantarflexion contractions to 70% of their maximum voluntary contraction (MVC) level with the foot in neutral, inversion and eversion. One-dimensional statistical parametric mapping was applied to determine elongation differences. RESULTS: Elongation within a sub-tendon did not differ in the three foot positions. Elongation was similar between both sub-tendons at very low contraction levels, but GM sub-tendon elongation exceeded GL sub-tendon displacement significantly from 30% MVC. The elongation differences between the sub-tendons were not affected by foot position. SIGNIFICANCE: Greater GM sub-tendon elongation is likely caused by the greater force production capability of GM but may also indicate that the sub-tendons of GM and GL have different mechanical properties, which is currently unknown. Elongation differences were contraction level dependent suggesting that contributions of GM and GL to plantarflexion torque may also be contraction level dependent.


Assuntos
Articulação do Tornozelo/fisiologia , Pé/fisiologia , Músculo Esquelético/fisiologia , Tendões/fisiologia , Tendão do Calcâneo/fisiologia , Adulto , Feminino , Humanos , Contração Isométrica/fisiologia , Masculino , Pessoa de Meia-Idade , Torque
10.
J Am Podiatr Med Assoc ; 109(6): 431-436, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31755770

RESUMO

BACKGROUND: The aim of this study was to observe the pressure changes in the felt padding used to off-load pressure from the first metatarsal head, the effects obtained by different designs, and the loss of effectiveness over time. METHOD: With a study population of 17 persons, two types of 5-mm semicompressed felt padding were tested: one was C-shaped, with an aperture cutout at the first metatarsophalangeal joint, and the other was U-shaped. Pressures on the sole of the foot were evaluated with a platform pressure measurement system at three time points: before fitting the felt padding, immediately afterward, and 3 days later. RESULTS: In terms of decreased mean pressure on the first metatarsal, significant differences were obtained in all of the participants (P < .001). For plantar pressures on the central metatarsals, the differences between all states and time points were significant for the C-shaped padding in both feet (P < .001), but with the U-shaped padding the only significant differences were between no padding and padding and at day 3 (P = .01 and P = .02). CONCLUSIONS: In healthy individuals, the U-shaped design, with a padding thickness of 5 mm, achieved a more effective and longer-lasting reduction in plantar pressure than the C-shaped design.


Assuntos
Desenho de Equipamento , Pé/fisiologia , Ossos do Metatarso/fisiologia , Articulação Metatarsofalângica/fisiologia , Pressão , Adolescente , Feminino , Órtoses do Pé , Humanos , Masculino , Pessoa de Meia-Idade , Caminhada/fisiologia , Adulto Jovem
11.
Sensors (Basel) ; 19(20)2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31623248

RESUMO

In this paper, a stride detector algorithm combined with a technique inspired by zero velocity update (ZUPT) is proposed to reconstruct the trajectory of a pedestrian from an ankle-mounted inertial device. This innovative approach is based on sensor alignment and machine learning. It is able to detect 100% of both normal walking strides and more than 97% of atypical strides such as small steps, side steps, and backward walking that existing methods can hardly detect. This approach is also more robust in critical situations, when for example the wearer is sitting and moving the ankle or when the wearer is bicycling (less than two false detected strides per hour on average). As a consequence, the algorithm proposed for trajectory reconstruction achieves much better performances than existing methods for daily life contexts, in particular in narrow areas such as in a house. The computed stride trajectory contains essential information for recognizing the activity (atypical stride, walking, running, and stairs). For this task, we adopt a machine learning approach based on descriptors of these trajectories, which is shown to be robust to a large of variety of gaits. We tested our algorithm on recordings of healthy adults and children, achieving more than 99% success. The algorithm also achieved more than 97% success in challenging situations recorded by children suffering from movement disorders. Compared to most algorithms in the literature, this original method does not use a fixed-size sliding window but infers this last in an adaptive way.


Assuntos
Técnicas Biossensoriais , Monitorização Ambulatorial , Caminhada/fisiologia , Algoritmos , Tornozelo/fisiologia , Articulação do Tornozelo/fisiologia , Pé/fisiologia , Marcha/fisiologia , Humanos , Aprendizado de Máquina , Pedestres , Corrida/fisiologia
12.
Sensors (Basel) ; 19(20)2019 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-31614811

RESUMO

While controlling a lower limb exoskeleton providing walking assistance to wearers, the walking terrain is an important factor that should be considered for meeting performance and safety requirements. Therefore, we developed a method to estimate the slope and elevation using the contact points between the limb exoskeleton and ground. We used the center of pressure as a contact point on the ground and calculated the location of the contact points on the walking terrain based on kinematic analysis of the exoskeleton. Then, a set of contact points collected from each step during walking was modeled as the plane that represents the surface of the walking terrain through the least-square method. Finally, by comparing the normal vectors of the modeled planes for each step, features of the walking terrain were estimated. We analyzed the estimation accuracy of the proposed method through experiments on level ground, stairs, and a ramp. Classification using the estimated features showed recognition accuracy higher than 95% for all experimental motions. The proposed method approximately analyzed the movement of the exoskeleton on various terrains even though no prior information on the walking terrain was provided. The method can enable exoskeleton systems to actively assist walking in various environments.


Assuntos
Exoesqueleto Energizado , Extremidade Inferior/fisiologia , Pressão , Fenômenos Biomecânicos , Calibragem , Pé/fisiologia , Humanos , Articulações/fisiologia , Modelos Teóricos , Amplitude de Movimento Articular , Caminhada/fisiologia
13.
Gait Posture ; 74: 242-249, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31574408

RESUMO

BACKGROUND: Excessive foot pronation during running in individuals with foot varus alignment may be reduced by medially wedged insoles. RESEARCH QUESTION: This study investigated the effects of a medially wedged insole at the forefoot and at the rearfoot on the lower limbs angles and internal moments of runners with excessive foot pronation and foot varus alignment. METHODS: Kinematic and kinetic data of 19 runners (11 females and 8 males) were collected while they ran wearing flat (control condition) and medially wedged insoles (insole condition). Both insoles had arch support. We used principal component analysis for data reduction and dependent t-test to compare differences between conditions. RESULTS: The insole condition reduced ankle eversion (p = 0.003; effect size = 0.63); reduced knee range of motion in the transverse plane (p = 0.012; effect size = 0.55); increased knee range of motion in the frontal plane in early stance and had earlier knee adduction peak (p = 0.018; effect size = 0.52); reduced hip range of motion in the transverse plane (p = 0.031; effect size = 0.48); reduced hip adduction (p = 0.024; effect size = 0.50); reduced ankle inversion moment (p = 0.012; effect size = 0.55); and increased the difference between the knee internal rotation moment in early stance and midstance (p = 0.012; effect size = 0.55). SIGNIFICANCE: Insoles with 7˚ medial wedges at the forefoot and rearfoot are able to modify motion and moments patterns that are related to lower limb injuries in runners with increased foot pronation and foot varus alignment with some non-desired effects on the knee motion in the frontal plane.


Assuntos
Órtoses do Pé , Pé/fisiologia , Extremidade Inferior/fisiologia , Pronação/fisiologia , Corrida/fisiologia , Sapatos , Adulto , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , Feminino , Articulação do Quadril/fisiologia , Humanos , Cinética , Articulação do Joelho/fisiologia , Masculino , Pessoa de Meia-Idade , Análise de Componente Principal , Amplitude de Movimento Articular
14.
Medicine (Baltimore) ; 98(40): e17440, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31577765

RESUMO

To prove the equivalence of the Korean version of the Foot and Ankle Outcome Score (FAOS) in the printed (PFAOS) vs the electronic (EFAOS) form in a multicenter randomized study.Overall, 227 patients with ages ranging from 20 to 79 years from 16 dedicated foot and ankle centers were included. Patients were randomized into either a 'paper first' group (P-F group, n = 113) or an 'electronic device (tablet computer) first' group (E-F group, n = 114). The first evaluation either by paper (P-F group) or tablet (E-F group) was followed by a second evaluation the following day. The difference between the PFAOS and EFAOS results in each group was calculated and analyzed. To evaluate the benefit of each methodology, the time consumed per evaluation was compared and patients were asked which methodology they preferred and which was the easiest to use.There were no significant differences in age or sex between the groups. An intraclass correlation coefficient (ICC) value of 0.934 (95% confidence interval [CI]: 0.912-0.950, P < .001) was confirmed in PFAOS and EFAOS, showing a significant correlation between the 2 methodologies. EFAOS was completed in a shorter amount of time than PFAOS. The majority of patients agreed that EFAOS was easier to complete than PFAOS.The paper or electronic forms of the Korean adaptation of FAOS were considered equivalent. The shorter time of completion and the preference for the electronic version over paper by patients deems the electronic FAOS a promising option to consider in future.


Assuntos
Computadores de Mão , Pé/fisiologia , Medidas de Resultados Relatados pelo Paciente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Preferência do Paciente , Recuperação de Função Fisiológica , Reprodutibilidade dos Testes , República da Coreia , Fatores de Tempo , Adulto Jovem
15.
Med Sci Monit ; 25: 7720-7727, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31611547

RESUMO

BACKGROUND Unbalanced standing and gait asymmetry are common in individuals with musculoskeletal disorders. Achieving symmetrical posture and gait is an important goal of rehabilitation. This study investigated the biomechanical differences in the lower extremities observed immediately after an insole was used and without the use of different one-sided insoles. MATERIAL AND METHODS Thirty young, healthy adult males received 3 different insole interventions: experimental group A had a customized 3-dimensional (3D)-printed single-sided lateral wedge insole (CLWI) inserted on the left side, and experimental group B had on the left side, a traditional single insert. The control had unilateral flat insoles; no insole inserted into the socks. Motion mechanics and gait parameters were collected at the 2-time points, after insertion of the insole and after 20 minutes of walking with the insole. RESULTS Asymmetric posture and gait appeared immediately after using the 2 insoles (lower joint moment, P<0.05). Compared with the control group, the abnormal posture and gait of experimental group B after wearing the traditional insole for 20 minutes were not obvious (P>0.05). However, the asymmetrical posture and gait remained in experimental group A after wearing the CLWI for 20 minutes (P<0.05). The center of pressure (COP) trajectory of the left foot of experimental group A was significantly higher than that of experimental group B and the control group at the 2-time points (P<0.05). CONCLUSIONS The asymmetry of posture and gait can be observed in a short time using a customized 3D-printed single-sided lateral wedge insole. This experiment provides guidance for the application of customized 3D-printed single-sided lateral wedge insoles for gait rehabilitation.


Assuntos
Órtoses do Pé/tendências , Marcha/fisiologia , Postura/fisiologia , Adulto , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , China , Pé/fisiologia , Voluntários Saudáveis , Humanos , Articulação do Joelho/fisiologia , Extremidade Inferior/fisiologia , Masculino , Impressão Tridimensional , Caminhada/fisiologia
16.
Gait Posture ; 74: 194-199, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31550557

RESUMO

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.


Assuntos
Diabetes Mellitus/fisiopatologia , Neuropatias Diabéticas/fisiopatologia , Pé/fisiologia , Marcha/fisiologia , Caminhada/fisiologia , Adulto , Idoso , Análise de Variância , Fenômenos Biomecânicos , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
17.
Gait Posture ; 74: 212-217, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31561119

RESUMO

BACKGROUND: A growing body of literature supports the promising effect of real-time feedback to re-train runners. However, no studies have comprehensively assessed the effects of foots trike and cadence modification using different forms of real-time feedback provided via wearable devices. RESEARCH QUESTION: The purpose of the present study was to determine if a change could be made in foot strike pattern and plantar loads using real-time visual, auditory and combined feedback provided using wearable devices. METHODS: Visual, auditory and combined feedback were provided using wearable devices as fifteen recreational runners ran on a treadmill at self-selected speed and increased cadence. Plantar loads and location of initial contact were measured with a flexible insole system. Repeated measures ANOVAs with Bonferroni adjusted pair-wise comparisons were used to assess statistical significance. RESULTS AND SIGNIFICANCE: A significant effect of condition was noted on location of center of pressure (p < 0.01). Bonferroni-adjusted post-hoc comparisons showed that feedback conditions differed from baseline as well as the new cadence conditions, however did not differ from each other. A significant interaction effect (region x feedback) was found for plantar loads (maximum force P < 0.001). Significant effects of feedback were noted at the heel (P < 0.001), medial midfoot (P < 0.001), lateral midfoot (P < 0.001), medial forefoot (P = 0.003), central forefoot (P = 0.003), and great toe (P = 0.004) but not at the lateral forefoot (P = 0.6) or lateral toes (P = 0.507). SIGNIFICANCE: The unique findings of our study showed that an anterior shift of the center of pressure, particularly when foot strike modification was combined with 10% increased cadence. We found lower heel and midfoot loads along with higher forefoot and great toe loads when foot strike modification using real-time feedback was combined with increased cadence. Our findings also suggest that auditory feedback might be more effective than visual feedback in foot-strike modification.


Assuntos
Pé/fisiologia , Feedback Formativo , Corrida/fisiologia , Dispositivos Eletrônicos Vestíveis , Suporte de Carga/fisiologia , Adulto , Análise de Variância , Teste de Esforço , Feminino , Calcanhar/fisiologia , Humanos , Masculino , Atividade Motora/fisiologia , Sapatos , Dedos do Pé/fisiologia , Adulto Jovem
18.
J Sports Sci ; 37(23): 2735-2743, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31506014

RESUMO

The capacity of foot-strike running patterns to influence the functional properties of the Achilles tendon is controversial. This study used transmission-mode ultrasound to investigate the influence of habitual running foot-strike pattern on Achilles tendon properties during barefoot walking and running. Fifteen runners with rearfoot (RFS) and 10 with a forefoot (FFS) foot-strike running pattern had ultrasound transmission velocity measured in the right Achilles tendon during barefoot walking (≈1.1 ms-1) and running (≈2.0 ms-1). Temporospatial gait parameters, ankle kinematics and vertical ground reaction force were simultaneously recorded. Statistical comparisons between foot-strike patterns were made using repeated measure ANOVAs. FFS was characterised by a significantly shorter stance duration (-4%), greater ankle dorsiflexion (+2°), and higher peak vertical ground reaction force (+20% bodyweight) than RFS running (P < .05). Both groups adopted a RFS pattern during walking, with only the relative timing of peak dorsiflexion (3%), ground reaction force (1-2%) and peak vertical force loading rates (22-23%) differing between groups (P < .05). Peak ultrasound transmission velocity in the Achilles tendon was significantly higher in FFS during walking (≈100 ms-1) and running (≈130 ms-1) than RFS (P < .05). Functional Achilles tendon properties differ with habitual footfall patterns in recreational runners.


Assuntos
Tendão do Calcâneo/fisiologia , Pé/fisiologia , Marcha/fisiologia , Corrida/fisiologia , Tendão do Calcâneo/diagnóstico por imagem , Adulto , Tornozelo/fisiologia , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Ultrassonografia , Adulto Jovem
19.
Gait Posture ; 74: 102-107, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31499403

RESUMO

BACKGROUND: Although altered muscular control of the lumbopelvic region is one of the main risk factors for the development of low back pain and dysfunction, the influence of abnormal foot posture on lumbopelvic muscular function has not been investigated. RESEARCH QUESTION: To determine possible functional changes due to hyperpronation in the main muscles that control the lumbopelvic segment. METHODS: Kinematic and kinetic data were collected from 15 persons with hyperpronated feet and compared to a control group of 15 persons with normally aligned feet during the stance phase of gait. A generic OpenSim musculoskeletal model was scaled for each participant. A computed muscle control approach was used to produce a forward dynamic simulation of walking to determine muscle function. RESULTS: In the hyperpronation group significantly greater peak forces were observed in the erector spinae, iliopsoas and abdominals compared to controls. The former group showed peak latencies for abdominal muscles during early stance, and for erector spinae muscles during both early and late stance. No significant between-group differences were found in gluteus maximus muscle activation in the stance phase of gait. SIGNIFICANCE: Abnormal foot pronation can change the timing and intensity of lumbopelvic muscle activation. These changes may predispose people to develop secondary dysfunctions.


Assuntos
Pé/fisiologia , Marcha/fisiologia , Região Lombossacral/fisiologia , Músculo Esquelético/fisiologia , Pelve/fisiologia , Pronação/fisiologia , Adulto , Fenômenos Biomecânicos , Feminino , Humanos , Dor Lombar/fisiopatologia , Caminhada/fisiologia , Adulto Jovem
20.
Gait Posture ; 74: 142-147, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31525651

RESUMO

BACKGROUND: Static foot assessment is commonly performed in clinical practice to classify foot type for prescribing therapeutic interventions. Foot posture index is known to be a reliable indicator for foot position. Resting calcaneal stance position angle is used widely to determine foot posture and manufacture orthoses for pediatric flat foot patients. However, the relationship between foot posture index and resting calcaneal stance position angle in elementary school students is currently unclear. RESEARCH QUESTION: To investigate the relationship between foot posture index and resting calcaneal stance position angle in elementary school students. METHODS: Between January 2016 and December 2017, 208 elementary school students (average age, 10.3 years; range, 8-13 years) were enrolled for this study. All students were examined physically by one practitioner to measure foot posture index and resting calcaneal stance position angle. Age, gender, and body mass index were analyzed for factors associated with flat foot prevalence. This study was conducted as a retrospective comparative study. Associations between foot posture index and resting calcaneal stance position angle were determined by Pearson's correlation analysis. RESULTS AND SIGNIFICANCE: When measured by foot posture index and resting calcaneal stance position angle, the overall prevalence of flatfoot was 29% and 24% in the right foot and 26% and 23% in the left foot, respectively. Resting calcaneal stance position angle and foot posture index score showed moderate correlation in Pearson's correlation analysis (left side foot: kappa value = 0.710; right side foot: kappa value = 0.704). CONCLUSION: There is a moderate correlation between foot posture index and resting calcaneal stance position angle in elementary school students. Thus, both foot posture index with proven validity and reliability and resting calcaneal stance position widely used in the manufacture of insoles can be used as important biomechanical evaluation tools for feet in clinical settings.


Assuntos
Calcâneo/fisiologia , Pé/fisiologia , Postura/fisiologia , Adolescente , Criança , Feminino , Humanos , Masculino , Descanso , Estudos Retrospectivos
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