INSOLE-BASED ESTIMATION OF COMPLETE GROUND REACTION FORCE WITH GAUSSIAN KERNEL REGRESSION AND DATA EXPANSION

Author(s):  
QUAN HU ◽  
PING CAI

A method for estimating ground reaction force (GRF) with plantar pressure was proposed in this paper. The estimation model was constructed to approximate the nonlinear relationships between GRF and the plantar pressure according to the linear combinations of Gaussian kernel functions. Partial least squares regression (PLSR) was adopted to obtain model parameters and eliminate multicollinearity among the pressure components. The general model and subject-specific models were constructed for 12 male and 4 female subjects. Moreover, a data expansion method was introduced for the establishment of subject-specific model, which is implemented by searching and adopting the data with consistent statistical characteristics in a pre-established database. That approach is particularly meaningful for the group whose walking ability is limited or clinic where the force platform is not available. The NRMSEs (%) for general model were 5.27–7.85% (GRF_V), 7.35–8.53% (GRF_ML), and 8.82–10.54% (GRF_AP). The maximum NRMSEs (%) for subject-specific models were 5.02% (GRF_V), 9.91% (GRF_ML), and 10.23% (GRF_AP). Results showed that both general and subject-specific models achieved higher accuracy than existing methods such as linear regression and neural network methods.

2020 ◽  
Vol 36 (3) ◽  
pp. 134-140
Author(s):  
Piaolin Peng ◽  
Shaolan Ding ◽  
Zhikang Wang ◽  
Yifan Zhang ◽  
Jiahao Pan

The purpose of this study was to explore the immediate effects of running speed and midsole type on foot loading during heel–toe running. Fifteen healthy male college students were required to complete 3 running trials on an indoor 45-m tartan runway at 4 different speeds (3, 4, 5, and 6 m/s) using 2 different running footwear types (engineering thermoplastic polyurethane elastomer, polyurethane elastomer; and ethylene vinyl acetate, vinyl acetate). The ground reaction force and plantar pressure data were quantified. Significant speed effects were detected both in ground reaction force and plantar pressure-related data (P < .05). Vertical average loading rate was significantly less, and time to first peak occurred later for the polyurethane elastomer compared with vinyl acetate footwear (P < .05). The peak pressure of the heel, medial forefoot, central forefoot, lateral forefoot, and big toe was significantly less when subjects wore a polyurethane elastomer than vinyl acetate footwear (P < .05). Overall, our results suggested that, compared with the vinyl acetate footwear, the special polyurethane elastomer footwear that is adhered with thousands of polyurethane elastomer granules was effective at reducing the mechanical impact on the foot.


2008 ◽  
pp. 281-290
Author(s):  
J. Y. Lee Alex ◽  
Jia-Hao Chou ◽  
Ying-Fang Liu ◽  
Wei-Hsiu Lin ◽  
Tzyy-Yuang Shiang

Author(s):  
Chi-Yin Tse ◽  
Hamid Nayeb-Hashemi ◽  
Ashkan Vaziri ◽  
Paul K. Canavan

A single-leg landing is a common type of high-risk maneuver performed by athletes. The majority of anterior cruciate ligament injury is accounted for by non-contact mechanisms, such as single-leg landings. The purpose of this study was to develop a subject specific single-leg drop landing to analyze the kinematics and kinetics of two different types of landings. Kinematic data was analyzed at five points during the landing phase: initial contact (IC), peak vertical ground reaction force (pVGRF), peak joint reaction force (pJRF), maximum knee flexion (MKF), and maximum valgus angle (MFP). A linear relationship was noted in comparing the average maximum peak vertical ground reaction force, average maximum knee flexion, and average maximum valgus angle to the platform heights in both landing styles. An increase in platform height was directly related to increased knee valgus angle in both landing styles. Significant difference (p < 0.05) was noted in the peak vertical ground reaction force between the 60% and 80% platform heights, as well as between 60% and 100% with arms above. Landing with arms across the body yielded more significant difference (p < 0.05) between platform heights in both frontal and sagittal planes. However, comparing both landing styles to each other only yielded significant difference (p < 0.05) at the 100% platform height. A valgus-varus-valgus movement was observed in all landings, and is a probable contributor to single-leg landing ACL ruptures.


2021 ◽  
Author(s):  
Fatemeh Aghakeshizadeh ◽  
Amir Letafatkar ◽  
Peyman Aghaei Ataabadi ◽  
Mahdi Hosseinzadeh

Abstract Background: People suffering from flat foot show more movements in hindfoot and midfoot joints as compared to the others. The anti-pronation tapings are supposed to provide temporary external support for the medial longitudinal arch. The aim of this study was to examine the effects of two types of anti-pronation taping on the lower limb kinetics in flat foot people before and after performing a physical fatigue protocol. Methods: 20 male and female with flat foot aged 22.39 ± 2.02 years old were studied under three conditions (untaping, reverse-6 taping and low-dye taping) either before or after fatigue states. The maximum plantar pressure and ground reaction force were measured by an RSscan foot scan system during walking. Results: A statistically significant difference was observed after applying two types of taping (reverse-6 vs. low-dye taping) in the maximum plantar pressure perceived in metatarsus 1 (P = 0.016) and lateral heel (P = 0.044). In the post-fatigue conditions, there were significant differences between the two taping types in metatarsus 4 (P = 0.024). The maximum ground reaction force in toe 1 (P = 0.001), toe 2-5 (P = 0.001), metatarsus 5 (P = 0.001), and medial heel (P = 0.001) was significantly different between reverse-6 and Low-dye tapings. Conclusions: The results indicated that the low-dye and reverse-6 taping types can reduce the pressure on the medial side of the foot, and push it towards the lateral side. It is therefore suggested using taping as an effective treatment for redistribution of the pressure and force in sole of the foot in people with flat foot.


Author(s):  
Mizuki Kato ◽  
Arinori Kamono ◽  
Naomichi Ogihara

An ankle-foot orthosis is often prescribed in the rehabilitation of patients with neurological motor disorders such as hemiparesis. However, walking with a unilateral ankle-foot orthosis may not be effectively achieved just by trying to reproduce normal intact walking with a symmetrical gait pattern. Understanding skills to facilitate walking gait with a unilateral ankle-foot orthosis has implications for better rehabilitative interventions to help restore walking ability in patients with stroke. We, therefore, analyzed the kinematics and ground reaction forces of walking with and without an ankle-foot orthosis in healthy subjects to infer the possible skills to facilitate walking gait with a unilateral ankle-foot orthosis. Adult male participants were asked to walk with and without an ankle-foot orthosis across two force platforms set in a wooden walkway, and body kinematics and ground reaction force profiles in the sagittal plane were simultaneously recorded. We found that the forward tilting angle of the trunk at the time of toe-off of the leg with the ankle-foot orthosis was significantly larger than that of the leg without the ankle-foot orthosis, to adaptively compensate for the loss of ankle joint mobility due to the unilateral ankle-foot orthosis. Furthermore, the peak vertical ground reaction force at heel-contact was significantly larger in the leg without the ankle-foot orthosis than in the leg with the ankle-foot orthosis owing to the fact that the stance phase duration of the leg with the ankle-foot orthosis was relatively shorter. Such information may potentially be applied to facilitate walking training in stroke patients wearing a unilateral ankle-foot orthosis.


2019 ◽  
Vol 6 (1) ◽  
pp. 1602969
Author(s):  
Hamada Ahmed Hamada ◽  
Dalia Mosaad ◽  
Manal Fahim ◽  
Gehan Abd El-Samea ◽  
Amel Youssef ◽  
...  

2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Jennifer N. Jackson ◽  
Chris J. Hass ◽  
Benjamin J. Fregly

Computational walking simulations could facilitate the development of improved treatments for clinical conditions affecting walking ability. Since an effective treatment is likely to change a patient's foot-ground contact pattern and timing, such simulations should ideally utilize deformable foot-ground contact models tailored to the patient's foot anatomy and footwear. However, no study has reported a deformable modeling approach that can reproduce all six ground reaction quantities (expressed as three reaction force components, two center of pressure (CoP) coordinates, and a free reaction moment) for an individual subject during walking. This study proposes such an approach for use in predictive optimizations of walking. To minimize complexity, we modeled each foot as two rigid segments—a hindfoot (HF) segment and a forefoot (FF) segment—connected by a pin joint representing the toes flexion–extension axis. Ground reaction forces (GRFs) and moments acting on each segment were generated by a grid of linear springs with nonlinear damping and Coulomb friction spread across the bottom of each segment. The stiffness and damping of each spring and common friction parameter values for all springs were calibrated for both feet simultaneously via a novel three-stage optimization process that used motion capture and ground reaction data collected from a single walking trial. The sequential three-stage process involved matching (1) the vertical force component, (2) all three force components, and finally (3) all six ground reaction quantities. The calibrated model was tested using four additional walking trials excluded from calibration. With only small changes in input kinematics, the calibrated model reproduced all six ground reaction quantities closely (root mean square (RMS) errors less than 13 N for all three forces, 25 mm for anterior–posterior (AP) CoP, 8 mm for medial–lateral (ML) CoP, and 2 N·m for the free moment) for both feet in all walking trials. The largest errors in AP CoP occurred at the beginning and end of stance phase when the vertical ground reaction force (vGRF) was small. Subject-specific deformable foot-ground contact models created using this approach should enable changes in foot-ground contact pattern to be predicted accurately by gait optimization studies, which may lead to improvements in personalized rehabilitation medicine.


2006 ◽  
Vol 96 (2) ◽  
pp. 107-115 ◽  
Author(s):  
Claudia Giacomozzi ◽  
Maria Grazia Benedetti ◽  
Alberto Leardini ◽  
Velio Macellari ◽  
Sandro Giannini

There is little knowledge of the functional performance of patients with talocalcaneal coalition because of the marginal quantitative information accessible using current motion-analysis and plantar pressure–measurement techniques. A novel system was developed for comprehensively measuring foot–floor interaction during the stance phase of gait that integrates instrumentation for simultaneously measuring bony segment position, ground reaction force, and plantar pressure with synchronization of spatial and temporal variables. An advanced anatomically based analysis of foot joint rotations was also applied. Tracking of numerous anatomical landmarks allowed accurate selection of three footprint subareas and reliable estimation of relevant local forces and moments. Eight patients (11 feet) with talocalcaneal coalition were analyzed. Major impairment of the rearfoot was found in nonsurgical patients, with an everted attitude, limited plantarflexion, and overloading in all three components of ground reaction force. Surgical patients showed more normal loading patterns in each footprint subarea. This measuring system allowed for accurate inspection of the effects of surgical treatment in the entire foot and at several footprint subareas. Surgical treatment of talocalcaneal coalition seems to be effective in restoring more physiologic subtalar and forefoot motion and loading patterns. (J Am Podiatr Med Assoc 96(2): 107–115, 2006)


Sign in / Sign up

Export Citation Format

Share Document