Understanding Of Foot Function Research Articles

Estimating three-dimensional foot bone kinematics from skin markers using a deep learning neural network model

The human foot is a complex structure comprising 26 bones, whose coordinated movements facilitate proper deformation of the foot, ensuring stable and efficient locomotion. Despite their critical role, the kinematics of foot bones during movement remain largely unexplored, primarily due to the absence of non-invasive methods for measuring foot bone kinematics. This study addresses this gap by proposing a neural network model for estimating foot bone movements using surface markers. To establish a mapping between the positions and orientations of the foot bones and 41 skin markers attached on the human foot, computed tomography scans of the foot with the markers were obtained with eleven healthy adults and thirteen cadaver specimens in different foot postures. The neural network architecture comprises four layers, with input and output layers containing the 41 marker positions and the positions and orientations of the nine foot bones, respectively. The mean errors between estimated and true foot bone position and orientation were 0.5 mm and 0.6 degrees, respectively, indicating that the neural network can provide 3D kinematics of the foot bones with sufficient accuracy in a non-invasive manner, thereby contributing to a better understanding of foot function and the pathogenetic mechanisms underlying foot disorders.

Differentiating Sitting, Standing, and Walking Through Regional Plantar Pressure Characteristics.

Prolonged static weight bearing (WBR) is thought to aggravate plantar heel pain and is common in the workplace, which may put employees at greater risk of developing plantar heel pain. However, objective measures of physical activity and sedentary behaviors in the workplace are lacking, making it difficult to establish or refute the connection between work exposure and plantar heel pain. Characterizing loading patterns during common workplace postures will enhance the understanding of foot function and inform the development of new measurement tools. Plantar pressure data during periods of sitting, standing, and walking were measured in ten healthy participants using the F-Scan in-shoe measurement system (Tekscan Inc, Boston, MA). Peak and average pressure, peak and average contact area, and average pressure differential were analyzed in ten different regions of the foot. A two-way repeated measures analysis of variance (ANOVA) assessed the posture by foot region interaction for each measurement parameter; significant effects of posture by foot region were identified for all five measurement parameters. Ten foot region by measurement parameter combinations were found to significantly differentiate all three postures simultaneously; seven used pressure measures to differentiate while three used area measures. The heel, lateral midfoot (LM), and medial and central forefoot (CFF) encompassed nine of ten areas capable of differentiating all postures simultaneously. This work demonstrates that plantar pressure is a viable means to characterize and differentiate three common workplace postures. The results of this study can inform the development of measurement tools for quantifying posture duration at work.

The Midfoot Contributes to Power and Work During Single-limb Heel Rise

Category: Midfoot/Forefoot Introduction/Purpose: Single-limb heel rise (HR) is used to evaluate muscle performance and clinical outcomes in people with foot and ankle pathology. While the midfoot contributes 13% of total foot/ankle work to forward propulsion during gait, healthy HR performance remains primarily characterized by ankle function. Similar to its function during gait, the midfoot may also generate power during HR to provide the stability needed for ankle push-off power. Further characterization of HR performance by evaluating midfoot kinetics may advance understanding of foot function in the clinical application of the HR task. The purpose of this study was to examine ankle and midfoot power and work during single-limb HR in healthy adults. Methods: Twelve healthy adults [Mean (SD): Age 31.3 (4.9) years; BMI 25.2 (3.3) Kg/m2; 50% male] performed twenty barefoot single-limb heel rises. Multi-segment kinematic and ground reaction force data were recorded with an electromagnetic motion capture system and force plate. Subject-specific, three segment foot models (tibia, rearfoot, forefoot) were derived. Inverse dynamic calculations were performed to obtain ankle and midfoot peak positive and negative powers (joint torque x segmental velocity), as well as the timing of peak powers (% of the heel rise). Midfoot work (integral of power with respect to time), reflecting energy production, was examined as a percentage of the entire work performed at the ankle and midfoot during HR. Group descriptive data were examined as mean (standard deviation) [95% confidence interval]. Results: Ankle peak positive power was 2.8 (0.8) [2.2 - 3.3] W/Kg and occurred during the ascent phase at 7% HR (Figure 1). Midfoot peak positive power was 0.5 (0.2) [0.3 - 0.6] W/Kg occurring at 6%. Ankle peak negative power was 2.1 (0.6) [1.7 - 2.4] W/Kg and occurred during the descent phase at 84% HR. Midfoot peak negative power was 0.4 (0.2) [0.2 - 0.5] W/Kg occurring at 83%. The proportion of midfoot work to total work performed was 13.5 (5.7) [9.8 - 17.1] %. Conclusion: Study findings advance understanding of foot function by demonstrating the contribution of midfoot power and work during HR in healthy adults. Midfoot peak powers were approximately 18% of ankle powers and occurred at similar times during HR. Further, midfoot energy production appears to be an important aspect of healthy HR performance because approximately 14% of the total foot/ankle work occurs at the midfoot. Since active internal muscle and ligament mechanisms are attributed to midfoot power generation, practitioners should consider midfoot tissue loading and muscle performance when implementing the HR task in clinical practice.

Traction reinforcement in prehensile feet of harvestmen (Arachnida, Opiliones).

Prehensile and gripping organs are recurring structures in different organisms that enhance friction by the reinforcement and redirection of normal forces. The relationship between organ structure and biomechanical performance is poorly understood, despite a broad relevance for microhabitat choice, movement ecology and biomimetics. Here, we present the first study of the biomechanics of prehensile feet in long-legged harvestmen. These arachnids exhibit the strongest sub-division of legs among arthropods, permitting extreme hyperflexion (i.e. curling up the foot tip). We found that despite the lack of adhesive foot pads, these moderately sized arthropods are able to scale vertical smooth surfaces, if the surface is curved. Comparison of three species of harvestmen differing in leg morphology shows that traction reinforcement by foot wrapping depends on the degree of leg sub-division, not leg length. Differences are explained by adaptation to different microhabitats on trees. The exponential increase of foot section length from distal to proximal introduces a gradient of flexibility that permits adaptation to a wide range of surface curvature while maintaining integrity at strong flexion. A pulley system of the claw depressor tendon ensures the controlled flexion of the high number of adesmatic joints in the harvestman foot. These results contribute to the general understanding of foot function in arthropods and showcase an interesting model for the biomimetic engineering of novel transportation systems and surgical probes.

Altered dynamic foot kinematics in people with medial knee osteoarthritis during walking: a cross-sectional study.

Footwear and insoles are used to reduce knee load in people with medial knee osteoarthritis (OA), despite a limited understanding of foot function in this group. The aim of this study was to investigate the differences in foot kinematics between adults with and without medial knee OA during barefoot walking. Foot kinematics were measured during walking in 30 adults; 15 with medial knee OA (mean age was 67.0 with a standard deviation (SD) of 8.9 years; height was 1.66 with SD of 0.13 m; body mass was 84.2 with SD of 15.8 kg; BMI was 30.7 with SD of 6.2 kg/m(2); K-L grade 3: 5, grade 4: 10) and 15 aged and gender matched control participants with 12 motion analysis cameras using the IOR multi-segment foot model. Motion of the knee joint, hindfoot, midfoot, forefoot and hallux were compared between groups using clustered linear regression. The knee OA group displayed reduced coronal plane range of motion of the midfoot (mean 3.8° vs. 5.4°, effect size=1.1, p=0.023), indicating reduced midfoot mobility. There was also a reduced sagittal plane range of motion at the hallux in the knee OA group compared to the control group (mean 29.6° vs. 36.3°, effect size=1.2, p=0.008). No statistically significant differences in hindfoot or forefoot motion were observed. People with medial knee OA display altered foot function compared to healthy controls. As foot and knee function are related, it is possible that altered foot function in people with knee OA may influence the effects of footwear and insoles.

(vi) Anatomy and biomechanics of the foot and ankle

Abstract The foot is a complex anatomical and biomechanical structure. It functions to allow stable stance, ambulation and the effective transfer of force through the lower limb. A thorough understanding of how the foot and ankle achieve this is essential for planning surgery and avoiding the consequences of nerve injury, poor wound healing and disrupted function. This review looks at the current understanding of foot function in the context of gait, biomechanics and relevant surgical anatomy.

REPRESENTATION OF ANKLE-FOOT KINEMATICS USING AN ANALYTICAL FOOT ROLLOVER MODEL

INTRODUCTION The human foot is a highly intricate structure comprising numerous bones, muscles, ligaments and synovial joints. As the only part in contact with the substrate, it plays a very important role in both supporting body-weight and in shock absorption during human locomotion. Although very complex models might be useful to gain insight into some specific clinical problems, simpler models could provide sufficient understanding of foot function for locomotion and rehabilitation studies [1,2,5].

15.33 Methylphenidate treatment improves cognitive function and gait performance in patients with Parkinson's disease

Footwear and insoles are used to reduce knee load in people with medial knee osteoarthritis (OA), despite a limited understanding of foot function in this group. The aim of this study was to investigate the differences in foot kinematics between adults with and without medial knee OA during barefoot walking.Foot kinematics were measured during walking in 30 adults; 15 with medial knee OA (mean age was 67.0 with a standard deviation (SD) of 8.9 years; height was 1.66 with SD of 0.13 m; body mass was 84.2 with SD of 15.8 kg; BMI was 30.7 with SD of 6.2 kg/m2; K–L grade 3: 5, grade 4: 10) and 15 aged and gender matched control participants with 12 motion analysis cameras using the IOR multi-segment foot model. Motion of the knee joint, hindfoot, midfoot, forefoot and hallux were compared between groups using clustered linear regression.The knee OA group displayed reduced coronal plane range of motion of the midfoot (mean 3.8° vs. 5.4°, effect size = 1.1, p = 0.023), indicating reduced midfoot mobility. There was also a reduced sagittal plane range of motion at the hallux in the knee OA group compared to the control group (mean 29.6° vs. 36.3°, effect size = 1.2, p = 0.008). No statistically significant differences in hindfoot or forefoot motion were observed.People with medial knee OA display altered foot function compared to healthy controls. As foot and knee function are related, it is possible that altered foot function in people with knee OA may influence the effects of footwear and insoles.

Measurement of plantar pressure distribution in hemiplegic children: changes to adaptative gait patterns in accordance with deficiency

Objective. A comparison of plantar pressure distribution in hemiplegic children with a healthy control group was performed to illustrate the link between the changing dynamics during the stance phase and the degree of deficiency. Design. Twenty three healthy control subjects and two groups of six hemiplegic children with minor and major spasticity were tested. Background. In previous studies, it was shown that the musculoskeletal dysfunction due to spasticity disturbed the hemiplegic gait pattern, for example reduced walking speed and step length. However, plantar pressure measurements which would help to understand the pathological gait mechanisms have not been studied. Methods. The stance phase parameters measured included spatio-temporal data and the relative impulse measurements during consecutive gait cycles. The relative impulses under eight plantar areas were determined with an in-shoe plantar pressure measurement device. Results. Each group had a specific plantar pressure distribution profile that varied with the degree of deficiency. The most significant differences were found beneath the midfoot, the first metatarsal head and the hallux. Conclusion. The neuromuscular disorders and foot deformities due to the cerebral lesion modified the contact of the foot with the ground, and led to specific plantar pressure distribution profiles. The equinovarus, with clawed-toe deformity due to greater spasticity, seemed to be an important factor in disturbances of the terminal stance phase. However, the spastic hemiplegic subjects seemed to adopt a gait pattern required for optimal stability. Relevance From previous work, comparable data were available only for the hemiparetic adult patients. In-shoe pressure data from spastic hemiplegic children can provide detailed information specific to each region of contact for the support of diagnosis, a clinical decision or the prescription of appropriate footwear, braces or othoses. Both peak pressure and local impulse have proven to be valuable for the understanding of foot function, lower extremity dysfunctions and walking strategies.