• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1527-1530
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• 2002

Factor analysis was applied to the phenotypic correlation matrix of 15 linear type traits (scored linearly 1 to 50 points) for 2035 Holstein cows of 38 sires computed from data collected between 1988 and 1992 in Beijing Shuangqiao Farm and Beijing Xijiao Farm. The 15 linear type traits were stature, body strength, body depth, dairy form, rump angle, rump length, rump width, rear leg side view, foot angle, fore udder attachment, rear udder height, rear udder width, udder cleft, udder depth and teat placement rear view. The first four components accounted for 49.1% of the total variance in type scores. Factor 1 reflected strong cows, with deep bodies, with long and wide rumps, and tall in stature. Factor 2 reflected cows with well attached fore udders, wide rear udders and whose udders were supported by strong suspensory ligaments with close teat placement. Factor 3 reflected cows with good dairyness, sickled in the hocks, high rear udders and udder floors above the hocks. Factor 4 reflected cows with sloping rumps from hooks to pins and with steep foot angle. Principal component and factor analyses are useful to clarify the relationships among type traits.

• Korean Journal of Applied Biomechanics
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• v.22 no.2
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• pp.183-191
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• 2012

The objective of this study was to evaluate the plantar foot pressure of skilled and unskilled players during a free throw. The experiment performed here in measured the movement route of the mean foot pressure, maximum foot pressure, and center of pressure in four event zones (ready, maximum knee flexion, release event, and maximum knee extension) for both groups while they were wearing the plantar foot pressure measurement equipment under identical conditions. The major findings are as follows. When getting ready (RD) during a free throw, the skilled player group had higher mean and maximum foot pressures, although neither variable showed significant differences statistically. For the maximum knee flexion (MF) during a free throw, the skilled player group had higher mean and maximum foot pressures, but only the mean foot pressure significantly differed statistically. For the release event (RE) during a free throw, the unskilled player group had higher mean and maximum foot pressures, but only the mean foot pressure significantly differed statistically. During the maximum knee extension (ME) of a free throw, the unskilled player group had a higher mean foot pressure, and the skilled player group had a higher maximum foot pressure. No significant correlation was found between the two groups. For the skilled player group, movement towards the center of pressure showed a stable form that moved from the rear to the front and from side to side during a free throw. For the unskilled player group, movement towards the center of pressure was unstable, which made it impossible to move from the rear to the front and from left to right.

• Journal of Fashion Business
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• v.28 no.1
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• pp.83-97
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• 2024

A plantar pressure mat with visual notifications was developed to confirm whether individuals can effectively balance themselves and correct imbalances. The sensor-embedded mat was made with a commercial yoga mat, and was tested on seven working women in their 30s to determine plantar pressure distribution when standing and squatting, and if they could recognize and correct imbalances with visual feedback. The study found that visual notifications significantly changed the plantar pressure ratio of the forefoot and hindfoot, as well as the left and right foot plantar pressure ratio. Without notifications, the center of gravity was more concentrated in the rear foot than the forefoot in both standing and squatting positions. Visual notifications showed that the center of gravity, which was largely focused on the rear foot, was distributed to the forefoot, resulting in a more evenly distributed center of gravity throughout the sole. For the change in left and right plantar pressure, the weight that was largely loaded on the left side was distributed to the right foot through the visual notification mat, confirming a more balanced plantar pressure.

• Korean Journal of Applied Biomechanics
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• v.29 no.2
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• pp.61-70
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• 2019

Objective: This study aimed to investigate the characteristics of the declination of the subtalar joint rotation axis and the structural features of the ankle joint complex such as rear-foot angle alignment and ligament laxity test between chronic ankle instability (CAI) patients and healthy control. Method: A total of 76 subjects and CAI group (N=38, age: $23.11{\pm}7.63yrs$, height: $165.67{\pm}9.54cm$, weight: $60.13{\pm}11.71kg$) and healthy control (N=38, age: $23.55{\pm}7.03yrs$, height: $167.92{\pm}9.22cm$, weight: $64.58{\pm}13.40kg$) participated in this study. Results: The declination of the subtalar joint rotation axis of the CAI group was statistically different from healthy control in both sagittal slope and transverse slope. The rear-foot angle of CAI group was different from a healthy control. Compared to healthy control, they had the structure of rear-foot varus that could have a high occurrence rate of ankle varus sprain. CAI group had loose ATFL and CFL compared to the healthy control. Conclusion: The results of this study showed that the deviation of the subtalar joint rotation axis and the structural features of the ankle joint complex were different between the CAI group and the healthy control and this difference is a meaningful factor in the occurrence of lateral ankle sprains.

• Korean Journal of Applied Biomechanics
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• v.13 no.2
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• pp.161-173
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• 2003

This study was performed to investigate the kinematic and kinetic differences between functional walking shoe(FWS) and general sports shoe(GSS). The subjects for this study were 4 male adults who had the walking pattern of rearfoot strike with normal feet. The movement of one lower leg was measured using force platform and 3 video cameras while the subjects walked at the velocity of 2/1.5 m/s. The findings of this study were as follows 1. The angle of lower leg-ground and angle of knee with FWS was greater than with GSS at the moment of strike the floor and the moment of second peak ground reaction force. The decreasing rate of angle of ankle was smaller in FWS from the strike phase to the second peak ground reaction force. These mean upright walking and round walking along the shoe surface. 2. The maximal Increased angle of Achilles tendon and the minimal decreased angle of rearfoot were smaller in FWS very significantly(p<0.001). Thus FWS prevent the excessive pronation of ankle and have good of rear-foot control. 3. The vortical ground reaction force and the rate of it to the BW were smaller in FWS statistically(p<0.001). The loading rate was smaller in FWS, too, and thess represent the reduction of load on ankle joint and prevention of injuries on it.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.1
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• pp.83-90
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• 2008

Taekwondo is a martial art form and sport that uses the hands and foot for attack and defense. Taekwondo basic motion is composed of the breaking, competition and poomsea motion. In the side kick among the competition motion, the impact force is larger than other kinds of kicks. The side kick with the front foot can be made in two steps. In the first step, the front foot is stretched forward from back stance free-fighting position. For the second step, the rear foot is followed simultaneously. Then, the kick is executed while entire body weight rests on the rear foot. In this paper, impact analysis of the human model for hitting posture is carried out. The ADAMS/LifeMOD is used in hitting modeling and simulation. The simulation model creates the human model to hit the opponent. As the results, the dynamic analysis of human muscle were presented.

• PNF and Movement
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• v.5 no.1
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• pp.1-8
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• 2007

Purposes : The purpose of this study was to measurement the change of cervical and lumbar range of motion according to plantar surface compliance in standing status. Method : The thirty normal adult(15men and 15women) aged between 20 and 35 were assigned to 3 group: first, in bottom piece shoe plantar form not changed the control group, the fore foot which was hard and the rear foot was soft the FHRS Group, the fore foot which was soft and the rear foot was hard the FSRH Group. The cervical and lumbar Range of motion was examined before and after adaptation with corresponding form types Results : This study investigated the change which appears when it will be soft and hard to be. As a result, FHRS group the cervical extension and lumbar flexion increased and the cervical flexion and lumbar extension decreased(p<0.05). In opposition, the FSRH group the cervical flexion and lumbar extension increased and the cervical extension and lumbar flexion decreased(p<0.05).

• Journal of the Korean Society of Physical Medicine
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• v.13 no.4
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• pp.131-138
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• 2018

PURPOSE: This study was conducted to compare the muscle activity of the proximal muscles of the lower limb according to the distance between the front and rear foot during lunge and to determine the most effective foot position for activation of the proximal muscle in the limb. METHODS: A total of 49 young adults were enrolled in this study. All subjects performed lunge by positioning the big toe of the back foot and the heel of the front foot at intervals of 40%, 60%, and 80% of the subject's own leg length. Muscle activity of the vastus medialis oblique, rectus femoris (RF), vastus lateralis oblique (VLO), gluteus medius, biceps femoris, and semitendinosus (ST) was then measured during three intervals of lunge operation. Each operation was measured three times for 10 seconds each, after which the average value was calculated and analyzed. RESULTS: There were significant differences in muscle activities of RF, VLO, and ST among the three intervals of the foot (p<.05). Post hoc, comparisons revealed lunge at 40% intervals resulted in higher RF and VLO activity than at 60% and 80% intervals (p<.05). In the semitendinosus muscle, 80% leg length intervals showed higher muscle activity than 40% (p<.05). CONCLUSION: Strengthening of the proximal muscles of the lower extremities during lunge exercise is considered to be most effective when placing the fore- and rear foot at intervals corresponding to 40% of the leg length.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.283-284
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• 2018

The rear side surface of tiles act have protrusions that helps secure the adhesion between the tile and the mortar for tile setting. Conventional height of the rear side usually ranges between 1 to 1.5 mm, and the molding method is classified in between press type and compression type during the manufacturing process, with most tiles being produced by the former method. In sites where adhesion failures were observed, tiles were taken to examine the cause of defect. It was determined that height was irregular at the rear side surface. Based on these findings, an experiment was conducted to determine the correlation between the rear surface and the bonding strength of tiles.

• Journal of Biomedical Engineering Research
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• v.10 no.3
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• pp.269-278
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• 1989

The initial impact at foot strike is produced by a slider type mechanical model, which can be measured using a force platform to evaluate various shoes. The lower extremity and foot motion was filmed by a 16mm high speed movie camera and several points on the rear half of the shoe and those near the trochanter and the lateral epicondyle were digitized to provide the linear and angular positions and velocities during impact. With these observed kinematics, a slider type foot strike simulator composed of guide rail and sliding dummy is designed. The simulator system makes the artificial foot of the dummy with running shoe on it to follow the foot strike motion. The dummy has the relevant mass-spring-damper system modeled after McMahon's. The motion of the model is drived by the gravity force and the generated motion alone with the ground reaction forces are monitored by the same procedures afore mentioned producing the initial foot strike impact similar to the onto observed in human gait.