• Journal of Institute of Control, Robotics and Systems
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• v.15 no.9
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• pp.959-966
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• 2009

An essential consideration when analyzing the gait of walking robots is their ability to maintain stability during walking. Therefore, this study proposes a vertical waist-jointed walking robot and gait algorithm to increase the gait stability margin while walking on the slope. First, the energy stability margin is compared according to the posture of the walking motion on slope. Next, a vertical waist-jointed walking robot is modeled to analyze the stability margin in given assumption. We describe new parameters, joint angle and position of a vertical waist-joint to get COG (center of gravity of a body) in walking. Finally, we prove the superiority of the proposed gait algorithm using simulation and conclude the results.

• PNF and Movement
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• v.20 no.3
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• pp.443-449
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• 2022

Purpose: This study aims to identify the differences in the muscle activity of the ankle joint muscle depending on the type of footwear (sneakers, mule sneakers, slippers) worn while walking on a slope. Methods: The subjects wore each shoe (sneakers, mule sneakers, and slippers) and walked on an 18-degree slope at a speed of 110 beats/min. While walking, the muscle activities of the tibialis anterior and medial gastrocnemius were measured. Of the three walking cycles, the second walking cycle was measured except for the first and third walking cycles, which are the beginning and end, and a three-minute break was taken to prevent muscle fatigue when the type of footwear was changed. Results: When walking on a slope, there was no significant difference in the muscle activity of the tibialis anterior according to the type of footwear. However, when walking on a slope, the difference in muscle medial gastrocnemius muscle activity was significant between sneakers and mule sneakers. There was also a significant difference between sneakers and slippers, but there was no significant difference between slippers and mule sneakers. Conclusion: There was no significant statistical difference between sneakers and mule sneakers, but there was a numerical difference. Therefore, the presence or absence of the shoe collar may affect the muscle activity of the medial gastrocnemius when walking on a slope. This can lead to patellofemoral pain syndrome caused by the excessive use of the quadriceps, so it must be considered that caution is needed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.3
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• pp.153-160
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• 2017

Gait analysis has been conducted in various environments, but the biomechanics during the transition from uphill walking to downhill walking have not been reported. The purpose of this study is to investigate the knee and ankle joint kinematics and kinetics during walking on a triangle-shaped slope compared with those during level walking. Kinematic and kinetic data of eighteen participants were obtained using a force plate and motion capture system. The greater peak ankle dorsiflexion angle and moment and the peak knee extension moment were observed (p<0.05) during both uphill and downhill walking on the triangle-shaped slope. In summary, uphill walking on a triangle-shaped slope, which showed a peak knee flexion of more than $50^{\circ}$ with greater peak knee extension moment, could increase the risk of patellofemoral pain syndrome. Downhill walking on a triangle-shaped slope, which involved greater ankle dorsiflexion excursion and peak ankle dorsiflexion, could cause gastrocnemius muscle strain and Achilles tendon overuse injury.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.15 no.2
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• pp.50-62
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• 2009

Purpose: to analyze and compare mucsle activity of Quadriceps femoris depending on the existence of taping while normal people walk forward and backward on treadmill when the slope and speed changes on treadmill. Method: Among 40 people who participated in this study, 20 experimenter who apply a taping walk forward and backward to 0%, 5%, 10% gradient per 2km/h and 4km/h using treadmill to give arbitrary walking behavior, 20 experimenter who doesn't apply a taping also walk forward and backward to 0%, 5%, 10% gradient per 2km/h and 4km/h using treadmill. To analyze muscle activity, We use an electromyography and Kinesio tape of good elasticity for obtained suffient effects in the experiment. Result: During backward walking in 2km/h, Vastus medialis and Vastus lateralis showed significant differences(p<0.05) when apply a taping. During backward walking in 2km/h, Vastus medialis and Rectus femoris, and Vastus lateralis all showed significant differences(p<0.05). During backward walking in 2km/h, Vastus medialis and Vastus lateralis showed significant differences in 10% gradient(p<0.05). During backward walking in 4km/h, Vastus medialis and Rectus femoris, and Vastus lateralis all showed significant differences(p<0.05). During backward walking in 4km/h, By the difference in slope, Vastus medialis and Vastus lateralis showed significant differences between 0% and 10% gradient(p<0.05). Conclusion: In comparison to muscle activity of Quadriceps femoris when apply a taping according to slope and speed during forward and backward walking on treadmill, when apply a taping and walk backward and 10% gradient on treadmill in 4km/h, maximum of muscle activity is shown.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.530-532
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• 2006

In this paper, we propose stable walking algorithm using ZMP for the biped robot in the slope-way. At first, we define discrete state variables that classified stable area and unstable area by center of mass from ZMP during slope-way walking. For the stable walking gait, the discrete state controller for determining the high-level and low-level decision making are designed. The high-level decision making is composed of the discrete state variables; left foot support phase, right foot support phase, flat-way, and slope-way. Then the continuous state controller is implemented for the low-level decision making using ZMP.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.8
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• pp.675-679
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• 2001

This paper presents walking algorithm for a quadruped robot that does not have an upper body. Tilting motion is added to the planned walking trajectory instead of using an extra body segment that is independent on walking trajectory. Area and tracking algorithms are proposed as tilting method and compared with that of off-line tilting and that of no tilting. Computer simulation shows that stability of tilted walking is more improved than that of the usual walking algorithm for general walking paths. It also shows that the tracking method guarantees stability and best mobility.

• Korean Journal of Applied Biomechanics
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• v.28 no.3
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• pp.165-173
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• 2018

Objective: The purpose of this study is to provide biomechanical basis data for the analysis of the maximum vertical ground reaction force, the maximum plantar pressure, the average plantar pressure, and the contact area according to the type of the insole through the insole insertion type foot pressure gauge. Method: In the treadmill, the slope was set at 10%, the first type A was worn at a walking speed of 3.5 km / h, and then walking was carried out using B, C, and D types. Data from 20 boots with consistent walking were extracted and plantar pressure data were collected and analyzed. Results: Functional insole was more effective than conventional insole for maximum vertical ground reaction force, maximum plantar pressure, average plantar pressure, and contact area at 10% of treadmill ramps. Conclusion: In this study, D-type insole supports the cushion in the middle part and supports the heel cup with hardness in the hind part, so that it is the most effective insole by lowering the plantar pressure and dispersing it more widely.

• The Journal of Korea Robotics Society
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• v.1 no.2
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• pp.197-202
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• 2006

We present the synergy effect of humanoid robot walking down on a slope and support vector machines in this paper. The biped robot architecture is highly suitable for the working in the human environment due to its advantages in obstacle avoidance and ability to be employed as human substitutes. But the complex dynamics in the robot and ground makes robot control difficult. The trajectory of the zero moment point (ZMP) in a biped walking robot is an important criterion used for the balance of the walking robots. The ZMP trajectory as dynamic stability of motion will be handled by support vector machines (SVM). Three kinds of kernels are also employed, and each result from these kernels is compared to one another.

• Korean Journal of Applied Biomechanics
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• v.16 no.2
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• pp.1-8
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• 2006

The purpose of this study was to evaluate normalized jerk according to shoes, slope, and velocity during walking. Eleven different test subjects used three different types of shoes (running shoes, mountain climbing boots, and elevated forefoot walking shoes) at various walking speeds(1.19, 1.25, 1.33, 1.56, 1.78, 1.9, 2, 2.11, 2.33m/sec) and gradients(0, 3, 6, 10 degrees) on a treadmill. Since there were concerns about using the elevated forefoot shoes on an incline, these shoes were not used on a gradient. Motion Analysis (Motion Analysis Corp. Santa Rosa, CA USA) was conducted with four Falcon high speed digital motion capture cameras. Utilizing the maximum smoothness theory, it was hypothesized that there would be differences in jerk according to shoe type, velocity, and slope. Furthermore, it was assumed that running shoes would have the lowest values for normalized jerk because subjects were most accustomed to wearing these shoes. The results demonstrated that elevated forefoot walking shoes had lowest value for normalized jerk at heel. In contrast, elevated forefoot walking shoes had greater normalized jerk at the center of mass at most walking speeds. For most gradients and walking speeds, hiking boots had smaller medio-lateral directional normalized jerk at ankle than running shoes. These results alluded to an inverse ratio for jerk at the heel and at the COM for all types of shoes. Furthermore, as velocity increased, medio-lateral jerk was reduced for all gradients in both hiking boots and running shoes. Due to the fragility of the ankle joint, elevated forefoot walking shoes could be recommended for walking on flat surfaces because they minimize instability at the heel. Although the elevated forefoot walking shoes have the highest levels of jerk at the COM, the structure of the pelvis and spine allows for greater compensatory movement than the ankle. This movement at the COM might even have a beneficial effect of activating the muscles in the back and abdomen more than other shoes. On inclines hiking boots would be recommended over running shoes because hiking boots demonstrated more medio-lateral stability on a gradient than running shoes. These results also demonstrate the usefulness of normalized jerk theory in analyzing the relationship between the body and shoes, walking velocity, and movement up a slope.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.4
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• pp.334-340
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• 2013

Using a relationship between step length and accelerometer output, step length can be estimated. In this paper, we propose a new step length estimation algorithm, which can be used both for the plane and the slope by compensating the slope angle. The slope angle is estimated using a barometer and the slope angle is compensated by observing how the slope affects the step length estimation. The proposed algorithm is verified using five adult man walking data, where the average length error is about 3% regardless of the slope.