• Journal of Korean Foot and Ankle Society
• /
• v.19 no.4
• /
• pp.176-180
• /
• 2015

Purpose: The aim of the current study is to report on the clinical and radiographic results after calcaneo-stop procedure in Korean children with symptomatic flexible flatfoot. Materials and Methods: Twenty-two children suffering pain along the medial aspect of midfoot with flexible flatfoot whose symptoms did not improve with conservative measures and therefore underwent calcaneo-stop procedure were identified retrospectively. Clinically, American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale and visual analogue scale (VAS) were evaluated. Radiographically, standing anteroposterior and lateral radiographs of the foot and Saltzman's alignment views were taken and talonavicular coverage angle, lateral talo-first metatarsal angle, and hindfoot alignment angles were measured and analyzed. Results: Clinically, AOFAS ankle-hindfoot scale improved from $70.3{\pm}5.6$ to $97.3{\pm}2.5$ and VAS improved from $6.4{\pm}1.6$ to $0.2{\pm}0.4$. Radiographically, talonavicular coverage angle improved from $28.3^{\circ}{\pm}12.3^{\circ}$ to $10.9^{\circ}{\pm}8.1^{\circ}$, lateral talo-first metatarsal angle improved from $-19.3^{\circ}{\pm}9.0^{\circ}$ to $-2.4^{\circ}{\pm}8.1^{\circ}$, and hindfoot alignment angle improved from valgus $11.9^{\circ}{\pm}10.0^{\circ}$ to $3.5^{\circ}{\pm}4.3^{\circ}$ at minimum 2-year follow-up. No complications occurred postoperatively. Conclusion: Calcaneo-stop procedure is a simple and very effective procedure for management of pediatric symptomatic flexible flatfoot that does not respond to conservative treatment.

• Korean Journal of Applied Biomechanics
• /
• v.15 no.2
• /
• pp.185-196
• /
• 2005

Recently among several tennis techniques forehand stroke has been greatly changed in the aspect of spin, grip and stance. The most fundamental factor among the three factors is the stance which consists of open, square and closed stance and it is very important to know the patterns of plantar pressure distribution for the better understanding of forehand stroke. Therefore, the purpose of this study was to investigate the change of plantar pressure distribution according to close, square and open stance patterns during forehand stroke in tennis. Three high school tennis players were recruited for the study and required to perform forehand stroke five consecutive trials in the condition of open, square and close stance. The forehand strokes were filmed with two digital video cameras and measured with pedar system for plantar pressure. The plantar regions under the foot were divided into 3 regions, which were forefoot, midfoot, and rear foot.. In conclusion, the first hypothesis, "The plantar pressure of close stance during forehand stroke would be distributed more largely to the left foot.", was rejected and the result showed that The plantar pressure of close stance during forehand stroke was distributed transferring from right foot to left foot similar to square stance. The second hypothesis, "The plantar pressure of square stance during forehand stroke would be distributed transferring from right foot to left foot." was accepted. The third hypothesis, "The plantar pressure of open stance during forehand stroke would be distributed more largely to the right foot.", was accepted.

• Journal of Korean Foot and Ankle Society
• /
• v.12 no.1
• /
• pp.41-46
• /
• 2008

Purpose: This study was designed to evaluate characteristics of foot pressure distribution with or without partial prosthetic foot in transmetatarsal amputee. Materials and Methods: The subjects were 9 transmetatarsal amputees. Foot pressures were measured at hallux, the $1^{st}-5^{th}$ metatarsal head (MTH), mid-foot, condyle area by F-scan system in amputated or contralateral foot during active walking. Results: In amputated foot, mean peak pressure was greatest in midfoot without prosthetic foot but it was greatest in hindfoot with prosthetic foot. In unaffected foot, although mean peak pressure was higher in hallux, and $1-5^{th}$ MTH compared to amputated foot, it was greatest in hind foot both with and without prosthetic foot. However, in unaffected foot, mean peak pressure significantly decreased in hallux and $5^{th}$ MTH after wearing the prosthetic foot. There was a significant difference in mean peak pressure in hallux and $5^{th}$ MTH between amputated and unaffected foot after wearing prosthetic foot. However, other region had no significant difference with or without prosthetic foot between feet. Conclusions: The use of partial prosthetic foot tends to shift weight bearing from the heel area to forefoot and could significantly reduce hind foot peak pressure and redistributed to peak pressure. The partial prosthetic foot can also offer the peak pressure to reduction both amputated foot and unaffected foot and help to toe off during walking.

• Korean Journal of Applied Biomechanics
• /
• v.30 no.1
• /
• pp.7-16
• /
• 2020

Objective: It is to find factors related to stability through analysis of plantar pressure factors according to the level of instability when performing Snatch. Method: Foot pressure analysis was performed while 10 weightlifters performed 80% of the highest level of Snatch, and motion was classified and analyzed in 3 grades according to the level of instability. Results: First, in Bad Motion, the movement distance of the pressure center in the direction of ML and AP was larger significantly in Phase 2. Second, in Phase 2, the number of zero-crossing in the AP direction was larger statistically significantly in Good Motion. Third, in the bad motion in Phase 3, the number of zero-crossing in the ML direction showed a significantly larger value. Fourth, in Phase 4, it was found that the more stable the lock out motion, the greater the activity of foot controlling in the left and right directions. Fifth, Phase 3, the greater the Maximum/Mean foot pressure value, the more stable the pulling action. Sixth, in Phase 2, the foot pressure was concentrated with a wide distribution in the midfoot and rearfoot. Seventh, the triggering number of the forefoot region was small in the last pull phase. Eighth, the number of triggers in the toe area was significantly higher during Good Motion in Phase 4. Conclusion: Summarizing the factors of instability in Snatch, there was no significant difference in Phase 1 for each condition. In order to enhance the stability in Phase 2, the sensory control ability in the AP direction is required, and focusing the foot pressing motion with a wide distribution in the middle and rear parts increases the instability. In Phase 3, it was found that the more unstable, the more sensory control activity was performed in the ML direction, the stronger the forefoot pressing action should be performed for a stable Snatch. In Phase 4, It is important that the feet sensory control activity in ML directions and the control ability of the toes in order to have stable Lock out motion.

• Journal of Korean Foot and Ankle Society
• /
• v.17 no.2
• /
• pp.121-129
• /
• 2013

Purpose: To evaluate the radiographic characteristics of the tarsometatarsal osteoarthritis with hallux valgus deformity and report the clinical results of the operative treatment. Materials and Methods: This is a retrospective study of 20 patients, 22 feet who had been operated for non-traumatic tarsometatarsal osteoarthritis with hallux valgus (TMT group) and control group of hallux valgus patients without tarsometatarsal osteoarthritis (26 patients, 28 feet) from April 2004 to July 2011. Radiographic characteristics were compared between the groups, using hallux valgus angle, $1^{st}-2^{nd}$ intermetatarsal angle, metatarsal length ratio, metatarsus adductus angle, talonavicular coverage angle, talus-$1^{st}$ metatarsal angle, calcaneal pitch angle and medial cuneiform height. Pre- and postoperative difference of $1^{st}-2^{nd}$ metatarsal declination angle and distance between the $1^{st}-2^{nd}$ metatarsal head were evaluated. The clinical results were evaluated by American Orthopaedics Foot and Ankle Society (AOFAS) midfoot scale and visual analogue scale (VAS). Results: Metatarsal length ratio was significantly larger in TMT group (p<0.001). Metatarsus adductus angle, talonavicular coverage angle, talus-$1^{st}$ metatarsal angle on lateral radiograph, calcaneal pitch angle and medial cuneiform height were different from control group (p<0.001, p<0.001, p=0.001, p=0.010, p=0.006). Postoperative declination of the $2^{nd}$ metatarsal and distance between the $1^{st}-2^{nd}$ metatarsal head were increased (p=0.009, p=0.001). The AOFAS and VAS score were improved (p<0.001, p<0.001). Conclusion: Non-traumatic osteoarthritis of the tarsometatarsal joints seems to be associated with long 2nd metatarsal length, metatarsus adductus and flatfoot deformity. Spur excision may be successful to relieve symptoms when the arthritis was diagnosed in early stage.

• Journal of Korean Foot and Ankle Society
• /
• v.17 no.2
• /
• pp.100-105
• /
• 2013

Purpose: To present radiographic characteristics and report the clinical results of the operative treatment of M$\ddot{u}$ller-Weiss disease. Materials and Methods: This is a retrospective study including 13 patients, 14 feet who had been operated for M$\ddot{u}$ller-Weiss disease between April 2006 and December 2011. Osteoarthritis of the peri-navicular joints were radiographically evaluated. Various range of peri-navicular fusion and joint-preserving surgeries according to patients' symptoms and radiographic findings were done. The clinical results were evaluated by American Orthopaedics Foot and Ankle Society (AOFAS) midfoot scale and visual analogue scale (VAS). Results: On radiographs, osteoarthritic changes were presented at talonavicular joint in 11 cases, calcaneocuboid joint in 7 cases, subtalar joint in 6 cases, naviculo-cuneiform joint in 1 case. The mean anteroposterior talocalcaneal angle was 16.6 degrees. On hindfoot alignment view, 6 cases were varus, 5 cases were neutral and 3 cases were valgus alignment. Fusion comprised 6 cases in triple fusion, 1 case in talonavicular-cuneiform fusion, 2 cases in talonavicualr fusion and 1 case in talonavicular & calcaneocuboid fusion. Joint-preserving surgeries were bony fragment excision of the lateral part of navicular & medial displacement calcaneal osteotomy in 1 case, bony spur excision of talonavicular joint in 1 case and medial displacement calcaneal osteotomy in 2 cases. The postoperative AOFAS and VAS score were improved significantly (p=0.000, p=0.000). Conclusion: In cases of M$\ddot{u}$ller-Weiss disease without osteoarthritic changes at peri-navicular joints, fragment excision of navicular, bony spur excision with or without medial displacement calcaneal osteotomy were effective operative treatments.

• Physical Therapy Korea
• /
• v.8 no.3
• /
• pp.1-10
• /
• 2001

The purpose of this study was to compare the static pressure, dynamic pressure, dynamic pressure-time integral, relative impulse, and contact time between the sound lower limb and amputated lower limb in trans-tibial amputee subjects using Parotec system. Seventeen trans-tibial amputee subjects wearing endoskeletal trans-tibial prosthesis voluntarily participated in this study. The results were as follows: 1) In static standing condition, there were significantly higher static pressure in sound lower limb insole sensor of 10, 14, 15, 18, 19, 23, and 24 and in amputated lower limb insole sensor of 9, 12, and 16 (p<.05). 2) In dynamic gait condition, there were significantly higher dynamic pressure in sound lower limb insole sensor of 2, 18, 22, 23, and 24 and in amputated lower limb insole sensor of 5, 9, 10, 11, 12, 14, 15, and 16 (p<.05). 3) In dynamic gait condition, there were significantly higher pressure-time integral in sound lower limb insole sensor of 2, 4, 18, 19, 20, 21, 23, and 24 and in amputated lower limb insole sensor of 5, 11, 12, and 15 (p<.05). 4) In dynamic gait condition, there were significantly higher relative impulse in sound lower limb insole sensor of 18, 19, 20, 22, 23, and 24 and in amputated lower limb insole sensor of 5, 9, 10, 11, 12, and 15 (p<.05). 5) In dynamic gait condition, there was significantly higher percentage of contact time in push off phase of sound lower limb and in support phase of amputated lower limb (p<.05). These results suggest that trans-tibial amputee subjects had characteristics of shortened push off phase due to unutilized forefoot and of lengthened support phase with higher pressure in the midfoot.

• The Journal of the Korea Contents Association
• /
• v.10 no.2
• /
• pp.268-276
• /
• 2010

This study was to investigate the knee joint flexion angle and the foot pressure during climbing with different slope. The 24 healthy subjects were participated. And foot pressure was investigated using Parotec system. The knee joint flexion angle were filmed to using a video camera on each slope($0^{\circ},\;3^{\circ},\;6{\circ},\;9^{\circ}$). And knee joint angle was investigated by Dartfish. The data were analyzed ANOVAs. In conclusion, there was significantly different that knee joint flexion angle related on each slope angle. In foot pressure, there was significantly different in lateral heel area(1 cell), medial midfoot area(9 cell), medial forefoot area(15, 16 cell) of left foot, and in lateral heel area(3 cell) of right foot. There was significantly different of foot pressure in lateral and medial heel when knee joint flexion angle is between $10^{\circ}$ and $20^{\circ}$. There was change of gait cycle according to walking slop angle increasing, and the initial contact phase was shorter, the foot pressure in lateral heel was lower.

• Journal of the Korean Society for Precision Engineering
• /
• v.30 no.4
• /
• pp.442-449
• /
• 2013

This study was to compare a domestic comfort shoes to the popular import(SAS$^{(R)}$) to gain a better understanding in biomechanical characteristics for shoe design for the elderly. For each shoe type, morphologic dimensions, shock absorption, and flexibility were assessed. From subjects(n = 20, $72.4{\pm}5.5$ years, $67.7{\pm}7.9$ kg), mean peak pressure(MPP) and contact area(CA) at the plantar surface were analyzed. The domestic shoes reflecting anatomic contour of the plantar surfaces of Asians resulted in wider CA(by 30.4 $cm^2$), higher shock absorption(by 2.4%) and stiffness(by 0.5 N/mm) than the import. With the domestic shoes, significantly less MPPs were found at the forefoot(by 42~49%) regions(p < .05) and higher CA was noted additionally at hallux and lessor toes(by 26~63%). More anatomically-contoured insole and favorable mechanical characteristics may help reduce the plantar pressures more effectively and more evenly, especially across the central forefoot and midfoot regions of the plantar surface, especially for the design of the comfort shoes for the elderly.

• Korean Journal of Applied Biomechanics
• /
• v.21 no.1
• /
• pp.67-75
• /
• 2011

The purpose of this study was to find the difference in gait patterns when elderly and young people walk by analyzing COP, Gait Line, Foot pressure pattern, and ensuring the original biomechanics technology of developing high performance footwear for the elderly. The subjects who took part in the test consist of 20 elderly people and 20 young people. The physical features of the elderly people that were recruited for the study are as below: 20 healthy male subjects(elderly people) with an average age of 75.43 yrs(S.D 6.46 yrs), weight of 68.10 kg(S.D 0.94 kg) and a height of 168.65 cm(S.D 1.47 cm). Foot pressure pattern data was collected using a EMED-AT system(Novel Gmbh, Germany) operating at the 50 Hz during walking. The results are as follow : COP route of the elderly leans to lateral compared to the young, and Gait Line from heel to toe is not clear and laterally curved. At the same time, a contact are aonthe midfoot is high compared to the young, and maximum force of the forefoot is low. As a result of analysis, in order to develop high performance footwear for the elderly, it is necessary to develop lasts and soles reflecting the elderly's gait patterns.