• Journal of the Ergonomics Society of Korea
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• v.20 no.1
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• pp.63-72
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• 2001

Rearfoot control can be defined as the relative ability of a shoe to limit the amount of subtalar joint pronation immediately following footstrike. A normal amount of pronation provides a means of decreasing peak forces experienced by the leg, but excessive pronation of the foot can be arised its injures. The purpose of this study is to compare amount of pronation according to a difference between medial and later hardness of shoe midsole for better design of running shops. The experiment is examined for 7 running shoes. 8 males. to measure the Achilles tendon angle and rearfoot angle using high speed camera. The results is conducted that the changes of Achilles tendon angle significantly differ at each test shoe with increased running speed. And, a difference between medial and lateral hardness of midsole affects rearfoot motion of runner. The displacements of maximal Achilles tendon angle described a amount of pronation motion is decreased when medial hardness of midsole is large more than lateral.

• The Journal of Korean Physical Therapy
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• v.14 no.3
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• pp.203-225
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• 2002

An excessive Q-angle has been implicated in the development of knee injuries by altering the lower-extremity locomotion kinematics. The purpose of this study was performed to examine the correlation between the Q-angle and the CTA during pronation and supination of the foot in the standing status. The participants of this examination were 60 adult(30 men and 30 women) who had no orthopaedic and neurological impairment, aged between 20 and 40years. The foot tilt(FT1)is made of acrylic plate and the slope of the surface is altered as $0^{\circ}$ pronation$(10^{\circ},\;20^{\circ},\;30^{\circ})$ and supination $(10^{\circ},\;20^{\circ},\;30^{\circ})$. The results were as follows : 1. The result about the Q-angle and the CTA by comparing pronation and supination of the foot There was statistical significance difference in the left /right Q-angle and the left/right CTA with pronation and supination of the foot(P<0.05). 2. The result about correlation in the left /right lower-extremity There were positive correlation between the right Q-angle and the right CTA and negative correlation except the supination$(30^{\circ})$ between the left Q-angle and the left CTA.

• The Journal of Korean Physical Therapy
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• v.14 no.4
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• pp.342-366
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• 2002

An excessive Q-angle has been implicated in the development of knee injuries by altering the lower-extremity locomotion kinematics. The purpose of this study was measured the Q-angle and the CTA when the foot moves pronation and supination of the foot in the standing status. The participants of this examination were 60 adult(30 men and 30 women) who had no orthopaedic and neurological impairment, aged between 20 and 40years. The foot tilt(FT 1)is made of acrylic plate and the slope of the suface is altered as $0^{\circ}$, pronation ($10^{\circ},20^{\circ},30^{\circ}$)and supination($10^{\circ},20^{\circ},30^{\circ}$). The results were as follows : 1. The result about the left/right Q-angle and the left/right CAT There was no statistical significant difference between the left and the right side of the Q-angle with different position of the foot(P > 0.05). While significant difference in the left CTA at the $0^{\circ}$, pronation($10^{\circ},20^{\circ},30^{\circ}$) and supination($10^{\circ},20^{\circ}$) has been observed(P < 0.05). 2. The result about the Q-angle and the CTA between male and female There was significant difference in the Q-angle between male and female with different position of the foot(P < 0.05). while significant different in the right CTA at the $0^{\circ}$ pronation ($20^{\circ}$)(P < 0.05), no significant difference in the left CTA have been observed(P > 0.05). 3. The result about correlation between the left/right Q-angle and the left/right CAT There was statistical significant positive correlation between the left/right Q-angle and the left/right CAT with the different position of the foot(P < 0.01).

• Korean Journal of Applied Biomechanics
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• v.16 no.4
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• pp.175-187
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• 2006

The purpose of this study was to find the relationship between Achilles tendon angle, angular velocity from 2D cinematography utilized to easily analyze the functions of shoes, ankle joint moment, knee joint moment, and hip joint moment from 3D cinematography utilized to predict the injury. Also, this study was to provide the optimal standard to analyze the injury related to the shoes. Subjects in this study were 30 university male students and 18 conditions (2 types of running speed, 3 of midsole hardness, 3 of midsole height) were measured using cinematography and force platform. The results were as following. 1) Hip joint abduction moment was effected by many variables such as running speed, midsole height, maximum achilles tendon angle, ground reaction force. 2) Knee joint rotational moment in running was approximately 1/10 - 1/4 times of the injury critical value and eversion moment was approximately 1/4 - 1/2 times of the injury critical value. 3) Ankle joint pronation moment in running was 1/3 - 1/2 times of the injury critical value. 4) Knee joint rotational moment was found to be irrelevant with maximum achilles tendon angle or angular velocity. 5) Pronation from running was thought to be relevant to rather eversion moment activity than rotational moment activity of knee joint. 6) Plantar flexion abductor of ankle showed significant relationship with the ground reaction force variable. 7) When the loading rate for ground reaction force in passive region increased, extensor tended to be exposed to the injury. Main variables in biomechanical analysis of shoes were impact absorption and pronation. Among these variables, pronation factor was reported to be relevant with knee injury from long duration exercise. Achilles tendon angle factor was utilized frequently to evaluate this. However, as the results of this study showed, the relationship between these variables and injury relating variable of knee moment was so important. Studies without consideration on this finding should be reconsidered and reconfirmed.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.4
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• pp.299-309
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• 2021

Purpose : The purpose of this study was to compare the ankle pronation squat with the general squat and investigate the effect on the geun varum and the muscles around the knee. Methods : Subjects were chosen as the target for squat exercise with the distance between the knees more than 5 cm. The selected 30 students were randomly divided into 15 pronation squat group and 15 general squat group, and performed five sets movements 20 times. Global postural system (GPS) and digital goniometer were used to check the distance between the knees and the Q angle, and muscle activity was measured with EMG during squat exercise. Results: The result is as follows. First, as a result of analyzing the change in the distance between the knees, the distance between the knees decreased and the Q angle increased in the pronation squat group after exercise. Second, as a result of analyzing the change in muscle activity of the peroneus longus, the muscle activity increased in the pronation squat group after exercise, and it was more effective than the general squat group. Third, as a result of analyzing the change in the VMO (vastus medialis oblique) and VL (vastus lateralis) muscle activity ratio, the activity ratio of the pronation squat group increased after exercise, and the imbalance in the VMO/VL muscle activity was decreased. Conclusion: The pronation squat exercise applied to the ankle will greatly affect what is made into a balanced leg as decreased of the distance between knees, increased of Q angle, increased of the muscle activity of the peroneus longus and the ratio of VMO/VL.

• Journal of Korean Foot and Ankle Society
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• v.12 no.1
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• pp.14-19
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• 2008

Purpose: We tried to understand the effects of the derotational closing wedge Akin osteotomy during the operation for the hallux valgus with pronation of great toe. Materials and Methods: Eighty five patients who had undergone Akin osteotomy among the eighty seven patients who had been treated with Scarf osteotomy with hallux valgus were included in this study. Derotational supination was added on the medial closing wedge Akin osteotomy at the base of proximal phalanx and it was secured with K-wire, headless screw or staple. We measured and analyzed pre- and post-operative hallux primus valgus angle and hallux pronational rotatory angle. Results: The hallux primus valgus angle improved an average of $14{\pm}2.98$ degrees to $-1{\pm}1.68$ degrees with the hallux pronational rotatory angle respectively from $24.8{\pm}7.64$ degrees to $4.7{\pm}4.22$ degrees. Conclusions: After the metatarsal osteotomy for the treatment of the hallux valgus with the pronation of great toe, derotational closing wedge Akin osteotomy can give us a belief that it can correct the hallux primus valgus angle and hallux pronational rotatory angle also and it can be a helpful method for minimizing the recurrence rate of the hallux valgus deformity.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.291-296
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• 2002

The midsole hardness of athletic footwear affects capability of absorbing impact shock and controls rearfoot movement during running and walking. The prior studies were focused on examining the proper hardness of footwear for rearfoot movement or to finding effective hardness for absorbing impact shock. The displacements of maximal Achilles tendon angle described a amount of pronation motion is decreased when medial hardness of midsole is large more than lateral. Increasing hardness of footwear midsole are effected to reduce maximum and intial pronation angle, but declined the ability of impact shock during heelstrike. For determination of effectiveness hardness of midsole, therefore, the study that makes a compromise between rearfoot movement and absorbing impact during footstrike must be performed. The purpose of this study is to examine quantitative values of rearfoot control and absorbing impact shock with different hardness of medial and lateral midsole on heel portion. The results are useful to define biomechanical hardness of midsole for developing running shoes. As variable for impact shock, accelerations onto shank and knee are measured during 4 running speeds (5, 7, 9, 11km/h). Also, maximum and $10\%$ pronation angle (Achilles tendon angle) were measured using high-speed camera.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.2
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• pp.108-112
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• 2024

The pronation foot can increase muscle activity, and may result in muscle fatigue and overuse syndromes. This paper aims to examine the relationships between muscle fatigue indices and pronation angles (PRA) larger than 20° for pronated foot subjects. Twelve subjects in the 15-61 age range were participated, and EMG of their biceps femoris were measured during treadmill walking at 4.5 km/h for 30 seconds. Slopes of the median frequency and the magnitude in the low frequency band were estimated respectively as muscle fatigue indices (MFIs). We hypothesized that the relationships between MFIs and PRA for the subjects in this paper be similar to those for normal ones. The test results demonstrated that we could obtain the significant correlation coefficients between MFIs and PRA (r>0.60; p<0.05).

• Journal of radiological science and technology
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• v.33 no.1
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• pp.19-24
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• 2010

The aim of this study was to evaluate the change of bone mineral density according to distal radius rotation and the correlations of the lowest BMD measured by DXA at the lumba versus distal radius. The eleven males were projected distal radius by DR X-ray and the measurement of BMD by DXA of the appropriate position of the forearm were performed on 21 males. The healthy 11 and 21 volunteers without any history of operations, anomalies, or trauma were enrolled. The experiment was performed by two methods. First, The DR X-ray was measured distal radius of 11 males in pronation and supination with three, six and nine degrees, including a neutral position. The ROI was measured by the m-view program on the PACS monitor. Second, The DXA was measured distal radius of 21 males in pronation and supination with five and ten degrees, including a neutral position to evaluate the changes of BMD according to the rotation. A correlation of the BMD in the distal radius with BMD that lumbar spine was performed, along with analysis of the data by SPSS 12.0v. The mean rotation angle of the distal radius about eleven males DR X-ray measured $7^{\circ}$ of pronation (82%, n = 9), $6^{\circ}$ of supination and $0^{\circ}$ of neutral of (9%, n = 1), The total average rotation angle in 11 male was $5.1^{\circ}$ of pronation. The rotation angle of the distal radius about twenty one males on DXA measured $7.2^{\circ}$ of pronation (43%, n = 9), $7^{\circ}$ of supination (24%, n = 5), and $0^{\circ}$ of neutral (33%, n = 7), The total average rotation angle in 21 people was $4.1^{\circ}$ of pronation. The correlation of the analysis of lumba and distal radius were r = 3.0, p = 0.18. consequently, The correlation was not significance. Because BMD of lumba was not coverd for BMD of the distal radius, with a neutral position, Pronation is needed for BMD in the distal radius with the rotation angle measuring at the lowest BMD. the rotation angle about five degrees of pronation of the distal radius is recommended.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.33-41
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• 2006

This study was to analysis three dimension angle of the upper extremity segment and trunk to putting the protector in women bowlers. For this study, the subjects selected 4 players of national and university team. All subjects putted in the same wrist support to satisfy the experiment conditions. To get three dimensions position coordination of swing motion used for 6 ProReflex MCU 240 camera produced by Qualisys. After position coordination calculation, Three dimension angle of the trunk and the upper extremity segment calculated for Matlab 6.5. the result is following; In the trunk motion, there were little differences among the subjects in a flexion and extension change. There were a lot of differences in motion change of the abduction-adduction and internal-external rotation, but the motion types translated to the adduction-abduction-adduction and from the internal rotation toward the external rotation. In the upper arm segment the Flexion and extension showed a consistent motion in the down swing and up swing phase. And the motion change of abduction-adduction and pronation-supination showed a abduction-adduction-abduction and pronation-supination change during swing phase. In the forearm segment changes, it showed a lot of differences among the subjects and a similar change with the upper arm segment. Especially, the hand segment showed a supination motion from the backswing apex to release phase, but for increasing a rotation velocity of ball, the hand segment translated toward pronation in follow throw phase.