Ground Reaction Force Distribution Research Articles

The Impact of Excessive Body Weight and Foot Pronation on Running Kinetics: A Cross-Sectional Study

BackgroundRunning exercise is an effective means to enhance cardiorespiratory fitness and body composition. Besides these health benefits, running is also associated with musculoskeletal injuries that can be more prevalent in individuals with excessive body weight. Little is known regarding the specific effects of overweight and foot pronation on ground reaction force distribution during running. Therefore, this study aimed to investigate the effects of overweight/obesity and foot pronation on running kinetics.MethodsEighty-four young adults were allocated to four experimental groups: non-excessive body weight/non-pronated feet; non-excessive body weight/pronated feet; overweight or obesity/ non-pronated feet and overweight or obesity/pronated feet. Biomechanical testing included participants to run at ~ 3.2 m/s over an 18-m walkway with an embedded force plate at its midpoint. Three-dimensional ground reaction forces were recorded and normalized to body mass to evaluate running kinetics from 20 running trials. Test–re-test reliability for running speed data demonstrated ICC > 0.94 for each group and in total.ResultsThe results indicated significantly lower vertical impact peak forces (p = 0.001, effect size = 0.12), shorter time to reach the vertical impact peak (p = 0.006, effect size = 0.08) and reduced vertical loading rate (p = 0.0007, effect size = 0.13) in individuals with excessive body weight (overweight or obesity/non-pronated feet group and overweight or obesity/pronated feet) compared with individuals non-excessive body weight (non-excessive body weight/non-pronated feet and non-excessive body weight/pronated feet). Moreover, the excessive body weight groups presented lower peak braking (p = 0.01, effect size = 0.06) and propulsion forces (p = 0.003, effect size = 0.09), lower medio-lateral loading rate (p = 0.0009, effect size = 0.12), and greater free moments (p = 0.01, effect size = 0.07) when compared to the non-overweight groups. Moreover, a significant body mass by foot pronation interaction was found for peak medio-lateral loading rate. Non-excessive body weight/pronated feet, excessive body weight/non-pronated feet and excessive body weight/pronation groups presented lower medio-lateral loading rates compared to non-excessive body weight/non-pronated feet (p = 0.0001, effect size = 0.13).ConclusionsOur results suggest that excessive body weight has an impact on ground reaction forces during running. We particularly noted an increase in medio-lateral and torsional forces during the stance phase. Individuals with excessive body weight appear to adapt their running patterns in an effort to attenuate early vertical impact loading.

Effect of Thoracic Kyphosis and Lumbar Lordosis on the Distribution of Ground Reaction Forces on the Feet.

IntroductionIn clinical practice, foot load receptors are very important in shaping the correct vertical posture and optimal equilibrium reactions. They are so important that stimulating them gives measurable effects in improving both balance and posture. Plantar pressure distribution is an important parameter that provides information on changes in a person’s posture, also during gait.AimThe aim of the work is to assess the effect of thoracic kyphosis and lumbar lordosis on the distribution of ground reaction forces on the feet.Materials and MethodsA total of 211 subjects aged 8–12 were examined. Body posture and distribution of ground reaction forces on the feet were assessed using the following parameters: thoracic kyphosis angle, lumbar lordosis angle, maximum pressure (static), average pressure (static), foot surface, distribution of foot pressure, maximum pressure (dynamic), time load (dynamic). DIERS formetric and DIERS pedoscan methods were used to measure the parameters.ResultsThe level of the kyphosis angle correlated positively with the percentage distribution of forefoot load in static conditions. The level of lordosis angle correlated positively with the foot surface and forefoot load. Positive correlation of the lordosis angle is also related to its connection with the difference in leg load during gait. A broader cause and effect view of body posture defects and the distribution of ground reaction forces on the feet can affect a more complete assessment of the correlation between these variables, contributing to more effective treatment of any disorders of the described phenomena.ConclusionThe size of thoracic kyphosis and lumbar lordosis affects the distribution of ground reaction forces on the feet. The effect of lumbar lordosis has a linear value in relation to percentage distribution of forefoot and heel loads.

Validation of the wearable sensor system - MoveSole® smart insoles

Biomechanical analysis of gait is commonly used in physiotherapy. Ground reaction forces during phases of gait is one element of kinetic analysis. In this article, we analyze if the MoveSole® smart insole is valid and accurate equipment for measuring ground reaction forces in clinical physiotherapy. MoveSole® StepLab is a mobile measurement system for instant underfoot force measurements during gait. Unique electromagnetic film (EMFI) based sensor technology and printed electronics production technology is integrated in the MoveSole® StepLab measurement system. The MoveSole® StepLab measures plantar ground reaction force distribution over the sensors and provides an estimation of the maximum total ground reaction force. We developed a two phase validation process to extract relevant parameters and compared the results to a Kistler force plate using the BioWare® analyzing program as a reference method. Our results show that MoveSole® smart insoles reach the strong level of accuracy needed in clinical work concerning highest ground reaction forces during step (Pearson correlation .822 - .875). The correlation of the time when the maximum ground reaction force occurred was moderate, e.g. during heel strike or toe-off (Pearson correlation natural gait speed .351 - .462, maximum gait speed .430). Our conclusion is that MoveSole® smart insoles are a potential tool for analyzing and monitoring gait ground reaction forces during physiotherapy processes.

The Influence of Hydraulic Ankles and Microprocessor-control on the Biomechanics of Trans-tibial Amputees During Quiet Standing on a 5° Slope.

Lower limb amputees have a high incidence of comorbidities, such as osteoarthritis, which are believed to be caused by kinetic asymmetries. A lack of prosthetic adaptation to different terrains requires kinematic compensations, which may influence these asymmetries. Six SIGAM grade E-F trans-tibial amputees (one bilateral) wore motion capture markers while standing on force plates, facing down a 5° slope. The participants were tested under three prosthetic conditions; a fixed attachment foot (FIX), a hydraulic ankle (HYD) and a microprocessor foot with a 'standing support' mode (MPF). The resultant ground reaction force (GRF) and support moment for prosthetic and sound limbs were chosen as outcome measures. These were compared between prosthetic conditions and to previously captured able-bodied control data. The distribution of GRF between sound and prosthetic limbs was not significantly affected by foot type. However, the MPF condition required fewer kinematic compensations, leading to a reduction in sound side support moment of 59% (p=0.001) and prosthetic side support moment of 43% (p=0.02) compared to FIX. For the bilateral participant, only the MPF positioned the GRF vector anterior to the knees, reducing the demand on the residual joints to maintain posture. For trans-tibial amputees, loading on lower limb joints is affected by prosthetic foot technology, due to the kinematic compensations required for slope adaptation. MPFs with 'standing support' might be considered reasonable and necessary for bilateral amputees, or amputees with stability problems due to the reduced biomechanical compensations evident.

Evaluation and Analysis of Different Types of Prosthetic Knee Joint Used by above Knee Amputee

Four prosthetic knee joints (polycentric knee weight activating-4bar and friction, extension assist controlled),(single axis knee weight activating and friction, internal extension assist controlled), (single axis knee weight activating-4bar and hydraulically, controlled) and (polycentric knee geometric locking-6bar, hydraulically controlled) for a trans-femoral patient were tested. The tests were conducted to find the maximum velocity as well as discussing the most comfortable prosthetic forthe patient and walking stability for these prosthetic knees by examining the gait cycle and measuring the ground reaction force (GRF), using force a plate device. Also, the interface pressure was measured between socket and stump muscles by using F-socket device to get the stress distribution during walking with a prosthetic knee. Results manifested that the polycentric knee geometric locking - 6bar, hydraulically controlled is the best because of the good homogenous distribution of GRF between the healthy and prosthetic limb, during which the difference between both the healthy and prosthetic limb is with the least value (4%).And, K4 gives the minimum value of differences in contact pressure between the left and right limb with a value of (24%), it alsoimparts the maximum symmetry between the left and right limb according to the gait cycle parameters.The best results of the interface pressures and kinovea velocity are achieved whenK4 is used with (132.4KPa, 0.71m/s), respectively. Finally, the polycentric knee geometric locking - 6bar, hydraulically controlled is the best according to the ANSYS results during which it yields the minimum values of Von-Mises stress with 14.24MPa and a maximum factor of safety of 3.11.

Influence of an asymmetrical load on ground reaction forces during gait

Carrying loads asymmetrically can leads to pathological changes in musculoskeletal system or to its overload and injury. This work aims to show and analyze the distribution of ground reaction forces under the feet when an individual carries a load asymmetrically with different methods of carrying. The data were collected for young males. The values of forces were recorded on a pedobarographic force platform for 0%, 5%, 10% and 15% of the body mass and different way of carrying the load (backpack carried on one shoulder, cross body laptop bag, laptop bag held in one hand and laptop bag carried on one shoulder). This kind of carrying the asymmetrical load is most commonly observed on the university facilities. For all considered cases of asymmetrical loading, there were statistically important differences at the ground reaction forces in comparison to gait without any load. This indicates that wearing asymmetrical loading should be avoided.

The relationship between foot arch flexibility and medial-lateral ground reaction force distribution

BackgroundOveruse running injury susceptibility has previously been associated with the magnitude and slope of ground reaction force profiles, most often in the vertical axis. However, despite the implications of excessive pronation and supination on injury susceptibility, very little research has examined the factors that might affect distribution of force in the medial-lateral directions. Research questionThe purpose of this study was to consider how foot structure, specifically arch flexibility, affects the distribution of ground reaction force between the medial-lateral and vertical planes of motion. MethodsTwenty-five participants were classified as having stiff or flexible arches, and three dimensional kinetic data were gathered while the volunteers ran at 7 mph on an instrumented treadmill. A mixed-effects ANOVA was used to analyze the effect of arch flexibility type on distribution of ground reaction force impulse in the medial and lateral directions. ResultsThe results suggest that individuals with relatively stiff arches experience a greater proportion of ground reaction force in the medial-lateral plane of motion, as compared with those with more flexible arches (p = 0.03). Further, the results suggest that most individuals, regardless of foot structure, experience greater impulse of force in the lateral than in the medial direction (p < 0.01). SignificanceConsidering previously explored relationships between ground reaction force, foot pronation/supination, and chronic running injuries, the results of this study suggest that arch flexibility could be used as a criterion for assessing injury susceptibility. Further, conclusions drawn from this study add to the discussion on the pros and cons of training or using devices to increase or restrict arch flexibility while running.

Microprocessor knees with 'standing support' and articulating, hydraulic ankles improve balance control and inter-limb loading during quiet standing.

IntroductionTrans-femoral amputees are at risk of musculoskeletal problems that are in part caused by loading asymmetry during activities, such as prolonged standing, particularly on uneven or sloped ground.MethodsFour prosthetic conditions were tested; microprocessor knee ‘standing support’ mode activated (ON) and deactivated (OFF), combined with a rigidly attached foot (RA) and with an articulating, hydraulic ankle-foot (HA). Five trans-femoral amputees and five able-bodied controls were measured using a motion capture system and a force plate while standing, facing down a 5° slope. Ground reaction force distributions and centre-of-pressure root-mean-square (COP RMS) were calculated as outcome measures.ResultsCompensatory kinematic adjustments were observed for RA conditions but not for HA conditions. HA-OFF reduced ground reaction force degree-of-asymmetry for all five amputees, compared to RA-OFF. RA-ON reduced ground reaction force degree-of-asymmetry for four amputees, compared to RA-OFF. In terms of balance, the HA conditions reduced the mean inter-limb COP RMS by 24–25% compared to equivalent RA conditions, while ON conditions reduced it by 9–11%, compared to equivalent OFF conditions.ConclusionsIt is important to consider both prosthetic knee and ankle technologies when prescribing devices to trans-femoral amputees. The combination of hydraulic ankle and knee standing support technologies produced outcomes closest to normal biomechanics.

Combining Push-Off Power and Nonlinear Damping Behaviors for a Lightweight Motor-Driven Transtibial Prosthesis

Transtibial prostheses play an important role in below-knee amputees’ daily activities. Our previous study presented a lightweight prosthesis with damping behaviors, which can adapt to different terrains. However, the proposed prosthesis cannot provide push-off during the stance phase. In this paper, we redesigned the mechanical structure, combining push-off and damping behaviors. The Peking University Robotic Trantibial Prosthesis (PKU-RoboTPro-) II makes a trade-off between push-off power and lightweight. Three unilateral transtibial subjects participated in the study. Gait symmetry and metabolic cost of walking with the proposed prosthesis were evaluated under conditions of three terrains and four walking speeds. The gait symmetry of the subjects using the prosthesis combining push-off and damping behaviors in stance time and ground reaction force distribution are improved. Meanwhile, the PKU-RoboTPro-II with a push-off mode can reduce energy expenditure, with an average 14% $\pm$ 8% reduction and a maximal 31% reduction under different conditions, compared with a non-push-off mode. When the weight of the lithium-ion rechargeable battery is 0.28 kg (2.6 Ah), it enables the new prosthesis combining push-off and damping behaviors to walk approximately 10 000 strides, on average.

Establishment of the simplified technique for estimating joint moments in foot during running

To prevent injuries such as stress fractures during long-distance running, it is important to clarify the joint loads on the foot. The purpose of this study was to establish a method of estimating joint moments on foot during stance phase in running. Loads on the ankle, tarsometatarsal, and metatarsophalangeal joints were estimated by a new simplified foot model with the three-dimensional force distribution on the bottom of shoe sole. Three-dimensional ground reaction force distributions were obtained from a running test with special shoes on which three-axis miniature force sensors had been mounted. Foot model consisted of three segments: toe, mid foot, and heel. Each segment was linked with metatarsophalangeal, tarsometatarsal, and ankle joints, respectively. By calculating inverse dynamics with this model, each joint moment component, which is the contribution of forces on each sensor to joint moments, could be estimated. Each joint moment was equivalent with the sum of moment components. Results showed that the tarsometatarsal and metatarsophalangeal joint moments are estimated during the whole stance phase. The moment component distributions of each joint could also be quantified. In comparison of the moment components corresponding to each metatarsal bone, the loads of the second- and third-ray metatarsal bones were higher than those of the others. Furthermore, the effect of sole thickness distribution on moment component distribution was also confirmed. Increase of sole thickness in the vicinity of the first and fifth metatarsal bone heads reduced the load of the second- and third-ray metatarsal bones. These results showed a possibility to prevent stress fractures on foot with the sole design.

Three-Axis Ground Reaction Force Distribution during Straight Walking

We measured the three-axis ground reaction force (GRF) distribution during straight walking. Small three-axis force sensors composed of rubber and sensor chips were fabricated and calibrated. After sensor calibration, 16 force sensors were attached to the left shoe. The three-axis force distribution during straight walking was measured, and the local features of the three-axis force under the sole of the shoe were analyzed. The heel area played a role in receiving the braking force, the base area of the fourth and fifth toes applied little vertical or shear force, the base area of the second and third toes generated a portion of the propulsive force and received a large vertical force, and the base area of the big toe helped move the body’s center of mass to the other foot. The results demonstrate that measuring the three-axis GRF distribution is useful for a detailed analysis of bipedal locomotion.

A fusion framework to estimate plantar ground force distributions and ankle dynamics

Gait analysis plays an important role in several conditions, including the rehabilitation of patients with orthopaedic problems and the monitoring of neurological conditions, mental health problems and the well-being of elderly subjects. It also constitutes an index of good posture and thus it can be used to prevent injuries in athletes and monitor mental health in typical subjects. Usually, accurate gait analysis is based on the measurement of ankle dynamics and ground reaction forces. Therefore, it requires expensive multi-camera systems and pressure sensors, which cannot be easily employed in a free-living environment. We propose a fusion framework that uses an ear worn activity recognition (e-AR) sensor and a single video camera to estimate foot angle during key gait events. To this end we use canonical correlation analysis with a fused-lasso penalty in a two-steps approach that firstly learns a model of the timing distribution of ground reaction forces based on e-AR signal only and subsequently models the eversion/inversion as well as the dorsiflexion of the ankle based on the combined features of e-AR sensor and the video. The results show that incorporating invariant features of angular ankle information from the video recordings improves the estimation of the foot progression angle, substantially.

A Lagrange-based generalised formulation for the equations of motion of simple walking models

Simple 2D models of walking often approximate the human body to multi-link dynamic systems, where body segments are represented by rigid links connected by frictionless hinge joints. Performing forward dynamics on the equations of motion (EOM) of these systems can be used to simulate their movement. However, deriving these equations can be time consuming. Using Lagrangian mechanics, a generalised formulation for the EOM of n-link open-loop chains is derived. This can be used for single support walking models. This has an advantage over Newton–Euler mechanics in that it is independent of coordinate system and prior knowledge of the ground reaction force (GRF) is not required. Alternative strategies, such as optimisation algorithms, can be used to estimate joint activation and simulate motion. The application of Lagrange multipliers, to enforce motion constraints, is used to adapt this general formulation for application to closed-loop chains. This can be used for double support walking models. Finally, inverse dynamics are used to calculate the GRF for these general n-link chains. The necessary constraint forces to maintain a closed-loop chain, calculated from the Lagrange multipliers, are one solution to the indeterminate problem of GRF distribution in double support models. An example of this method’s application is given, whereby an optimiser estimates the joint moments by tracking kinematic data.

Characteristics of autocorrelation structure of lower extremity functional laterality in disturbed and undisturbed bipedal upright stance

PurposeIt is posited that functional laterality is influenced by the generation and conduction of neural signals and therefore associated with sensorimotor control. The question arises if symmetry or asymmetry in sensorimotor processing affects the development of symmetric or asymmetric motor programs in the lower extremities. The purpose of the study was to examine the mechanisms of the human mobility moto-control – the process of maintaining body balance in a standing position through an appropriate course of distribution of ground reaction forces in a time frame, in a situation requiring lower extremity Movement symmetry.MethodsThe autocorrelation function was calculated for ground reaction forces (in the three orthogonal axes) registered during 45 s of bipedal upright stance in two conditions (eyes open and closed).ResultsMinor albeit significant deficiencies in postural muscle control were revealed as a function of time, as evidenced in the decay of the autocorrelation function to zero (T&lt;sub&gt;0&lt;/sub&gt;) between the right and left foot for the mediolateral ground reaction force signal. However, the results attest to symmetrical sensorimotor control between both feet.ConclusionsMotor actions (postural corrections) performed in long-duration tasks may have less of an effect on sensorimotor control than those applied in shorter duration projections. ANOVA and correlation analysis (across all variables) of the right and left foot T0 indicate considerable symmetry in the control of force magnitude and direction during upright standing.

The generation of centripetal force when walking in a circle: insight from the distribution of ground reaction forces recorded by plantar insoles.

BackgroundTurning involves complex reorientation of the body and is accompanied by asymmetric motion of the lower limbs. We investigated the distribution of the forces under the two feet, and its relation to the trajectory features and body medio-lateral displacement during curved walking.MethodsTwenty-six healthy young participants walked under three different randomized conditions: in a straight line (LIN), in a circular clockwise path and in a circular counter-clockwise path. Both feet were instrumented with Pedar-X insoles. An accelerometer was fixed to the trunk to measure the medio-lateral inclination of the body. We analyzed walking speed, stance duration as a percent of gait cycle (%GC), the vertical component of the ground reaction force (vGRF) of both feet during the entire stance, and trunk inclination.ResultsGait speed was faster during LIN than curved walking, but not affected by the direction of the curved trajectory. Trunk inclination was negligible during LIN, while the trunk was inclined toward the center of the path during curved trajectories. Stance duration of LIN foot and foot inside the curved trajectory (Foot-In) was longer than for foot outside the trajectory (Foot-Out). vGRF at heel strike was larger in LIN than in curved walking. At mid-stance, vGRF for both Foot-In and Foot-Out was higher than for LIN foot. At toe off, vGRF for both Foot-In and Foot-Out was lower than for LIN foot; in addition, Foot-In had lower vGRF than Foot-Out. During curved walking, a greater loading of the lateral heel occurred for Foot-Out than Foot-In and LIN foot. On the contrary, a smaller lateral loading of the heel was found for Foot-In than LIN foot. At the metatarsal heads, an opposite behaviour was seen, since lateral loading decreased for Foot-Out and increased for Foot-In.ConclusionsThe lower gait speed during curved walking is shaped by the control of trunk inclination and the production of asymmetric loading of heel and metatarsal heads, hence by the different contribution of the feet in producing the body inclination towards the centre of the trajectory.

B-13 ヒルランニング動作分析に基づくシューズグリップ性設計(シューズ)

In trail running, runners often meet slippery condition, such as uneven, wet, muddy surfaces with slope. On these surfaces, slip/fall risk gets drastically higher and running performance gets decreased due to traction loss between shoe and floor. Therefore, grip property is crucially important function in the designing process of trail running shoe. The purpose of this study is to clarify grip generation mechanism for trail running shoe designing based on uphill and downhill running (hill running) motion analyses. Ground reaction force (GRF) distributions in hill running were corrected by using a specific sensor shoe system. In comparison of GRF distribution between hill and flat surface running, higher horizontal force was produced in forefoot medial side area at kicking phase during uphill running. On the other hand in downhill, higher horizontal force got higher in lateral side of fore-midfoot area at the beginning of contact phase than that in flat surface running. Interestingly, it is confirmed that force direction of these areas was quite different between hill and flat surface running. In order to check the validity of obtained results, grip properties were evaluated with two pair of developed test shoes having different tread patterns. As a result, it was concluded that the oblique shaped tread patterns corresponding to horizontal force direction on hill running motion efficiently increase grip.

DEVELOPMENT OF AFFORDABLE OPTICAL BASED GAIT ANALYSIS SYSTEMS

This paper presents a review on the development of affordable optical based gait analysis systems at Institut Teknologi Bandung. The development started with a 2D inverse dynamic analysis of human gait using five linkages based on an experimental motion data. Using a simple system consist of a camera, LED markers and a PC, the position of the markers were obtained by capturing and processing digital images of markers attached to human body during motion. The marker positions data was then used for further kinematics and dynamic analyses. An in-house kinematic and kinetic software has been developed for this purpose. From the analyses, the spatiotemporal gait parameters such as stride-length, cadence, cycle-time, speed and joint angles can be obtained as well as forces and moments. In the second stage, the 2-D analysis was improved by using seven linkages to include the foot. Using this, the system has been able to analyze ankle angle, position of the centre of pressure and ground reaction force distribution. Currently, the development is continued further for a 3D dynamic analysis of human gait using two cameras and a PC. As an outcome of this development, a database of Indonesian normal gait was established. This result is the first data available for gait of Indonesian. It is hoped that the quantitative data provided by this system can help physicians to diagnose and plan the treatment for patients.

Experimental Analysis of the Distribution of Traction Coefficient in the Shoe-Ground Contact Area during Running

Relationship between shoe grip properties and distributions of traction coefficient, which is obtained from horizontal ground reaction force (GRF) divided by normal GRF, were experimentally investigated during running. The experiments were conducted with sensor shoes mounted miniature triaxial force sensors for the measurement of GRF distributions in contact area. In order to clarify influence of the grip property on GRF vectors distributions and traction coefficient distributions, two typed sensor shoes having different outer sole materials with high/low friction coefficients were developed. The results showed that traction coefficients for the low grip typed shoe decreased in the whole contact area at the end of stance phase during running. Furthermore, it was confirmed that contact area, directions of GRF vectors and traction coefficients locally changed depending on the grip property. As a result of relationship between distributions of propulsion force components at 19 local positions and stride length, production of propulsion force beneath toe area can efficiently acquire sufficient stride length to keep running speed.

The load distribution among three legs on the wall: model predictions for cockroaches

In a former study on terrestrial locomotion of cockroaches in the sagittal plane, it was hypothesised that the ground reaction force distribution among three legs synchronously in contact with a substrate is predominantly explained by joint torque minimisation within all three legs. We verified this hypothesis with a simple mechanical model in two dimensions, consisting of one body and three mass-less legs. Hereto, we calculated force distributions resulting from different optimisation criteria for varying slope angles of the substrate. We compared these distributions to each other and the few experimental findings available. We found that, for any slope angle, the force distribution rather seems to be derived from the fundamental “table” solution, i.e. equalised vertical and vanishing horizontal components (equivalent to pure force minimisation at zero slope), than from pure torque minimisation. For cockroaches, the “table” solution is likely to be modified by torque minimisation within the leading and the trailing leg. We demonstrate that the minimisation of leg forces and of interaction forces is fully equivalent. Moreover, our model predicts the force distribution for arbitrary slope angles. Based on our model calculations, we speculate that in terrestrial locomotion, some animals may rely on spring-mass model dynamics whatever slope angle to be overcome. This might only become evident when focusing movement analyses strictly on a gravity rather than on a substrate-based coordinate system.

New technique of three directional ground reaction force distributions

In this research, a shoe mounted miniature triaxial force sensors was developed to construct a new technique for the measurement of ground reaction force (GRF) distributions in contact area during running. Five sensor and 14 dummy block devices were mounted to a commercial marathon shoe. The shoe mass is 270.0 g. By using the shoe, distributions of lateral, longitudinal and normal direction force components at 19 local positions were measured by changing sensor arrangement at running speed of 5.5 min/km. The results showed contact periods and time history of GRFs at each position during stance phase was clearly different. It was confirmed that the resultant forces of the GRFs obtained from the sensor shoe gave close agreement with the GRFs obtained from the conventional force plate. Based on the distribution of the traction coefficient, which is calculated from the horizontal force divided by the vertical force, high traction coefficient area were clarified at the time 20 and 80% of stance phase. The distributions of the traction coefficient will imply area to apply structure and material design of the high grip shoe sole to avoid slip-related falls.