• Journal of the Korean Society of Physical Medicine
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• v.16 no.2
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• pp.1-8
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• 2021

PURPOSE: This study examined the effects of changes in the head direction (forward, upward 10° and downward 10°) on the quadriceps, center of pressure (COP), and foot pressure during squat exercises. The aim was to determine if the head direction could better activate the quadriceps muscle and provide a safer and stable squat posture during squat exercise. METHODS: Fifteen healthy college students were asked to stand on a Zebris, and three electrodes for sEMG were attached to their vastus medialis oblique (VMO), vastus lateralis (VL), and rectus femoris (RF) muscles. The participants then performed squatting exercises under three head directions (forward, upward 10°, and downward 10°). Surface electrodes were then used to record the EMG data during exercise. The Zebris FDM-SX was used to measure the foot pressure and COP of the participants. RESULTS: In squat exercise, the upward head direction group showed significantly higher VL activation than the downward head direction group (p < .05). The upward head direction group showed a significant backward change in the deviation of the COP than the downward and forward groups (p < .05). The upward head direction group showed a significant decrease in forefoot pressure than the downward and forward groups (p < .05) and an increase in the hindfoot pressure compared to the downward and forward groups (p < .05). CONCLUSION: The head direction upward in squat exercise has a positive effect on the quadriceps.

• Archives of Plastic Surgery
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• v.50 no.2
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• pp.188-193
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• 2023

Vascular injury following traumatic knee injury quoted in the literature ranges from 3.3 to 65%, depending on the magnitude and pattern of the injury. Timely recognition is crucial to ensure the revascularization is done within 6 to 8 hours from the time of injury to avoid significant morbidity, amputation, and medicolegal ramifications. We present a case of an ischemic limb following delayed diagnosis of popliteal artery injury after knee dislocation. Even though we have successfully repaired the popliteal artery, the evolving ischemia over the distal limb poses a reconstruction challenge. Multiple surgical debridement procedures were performed to control the local tissue infection. Free tissue transfer with chimeric latissimus dorsi flap was done to resurface the defect. However, the forefoot became gangrenous despite a free muscle flap transfer. His limb appeared destined for amputation in the vicinity of tissue and recipient vessels, but we chose to use a cross-leg free flap as an option for limb salvage.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.1
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• pp.25-29
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• 2009

The purpose of this study was to investigate the effect of two different lifting posture on the plantar foot pressure, force and COP(center of pressure) trajectory path during object lifting. Fourteen healthy adults who had no musculoskeletal disorders were instructed to lift with two postures(stoop and squat) and two object weights(empty box and 10 kg box). Plantar foot pressures, forces and COP trajectory path were recorded by the F-mat system(Tekscan, Boston, USA) during object lifting with barefoot. Plantar foot surface was defined as seven regions for pressure measurement; two toe regions, three forefoot regions, one midfoot region and one heel region. Paired t-test was used to compare the outcomes of peak pressure and maximum force with different two lifting postures and two object weights. Plantar peak pressure and maximum force under hallux was significantly greater in squat posture than stoop posture during the two different boxes lifting(p<.05). During the empty box lifting, maximum force under lessor toes was significantly less and plantar peak pressure under second metatarsal region was significantly greater in squat than stoop(p<.05). Maximum force under heel was significantly less in squat than stoop posture during 10kg box lifting(p<.05). Finally, COP trajectory path was significantly greater in squat than stoop(p<.05). These findings confirm that there are significantly change in the structure and function of the foot during the object lifting with different posture. Future studies should focus on the contribution of both structural and functional change to the development of common foot problems in adults.

• Korean Journal of Applied Biomechanics
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• v.25 no.4
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• pp.475-482
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• 2015

Objective : The purpose of this study was to investigate mean plantar foot pressure, maximum plantar pressure and ground reaction force, and center migration path of pressure according to the type of trekking shoes for the development of shoes. Method : Subjects of the study averaged $22.10{\pm}2.05years$ of age. Their average height was $169.27{\pm}7.62cm$ and their average weight was $64.34{\pm}10.22kg$. The method of this study was administered measuring 50 steps, at once, 3 times at a speed of 4 km/h and using the data of 30 steps. Pedar-X system measured the mean foot pressure, maximum foot pressure, mean maximum force, and center migration path of pressure by subjects' position while walking. Statistical analysis was performed by SPSS 23.0 using a paired t-test. Results : Results of the study showed Nestfit trekking shoes lower foot pressure of both feet in mean foot pressure and maximum foot pressure. Nestfit trekking shoes showed high ground reaction force (p<.001) in the midfoot, and low mean ground reaction force in the rearfoot. The center migration path of pressure showed the Nestfit trekking shoes were more stable than flat insole trekking shoes. Conclusion : It can be concluded that wearing Nestfit trekking shoes spreads pressure efficiently and induces walking stability because Nestfit trekking shoes spread the pressure of the forefoot and rearfoot to the midfoot and the center migration path of pressure shows regularly.

• Korean Journal of Applied Biomechanics
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• v.25 no.4
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• pp.489-498
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• 2015

Objective : The purpose of this study was to analyze the effects of the windlass mechanism in trail-walking shoe prototypes that can effectively support arches. A study of these effects should help with the development of a first-rate trail-walking shoe development guide for the distribution of quality information to consumers. Methods : The subjects were ten adult males who volunteered to participate in the study. Shoes from three companies, which will be referred to as Company S (Type A), Company M (Type B), and Company P (Type C), were selected for the experiment. The subjects wore these shoes and walked at a speed of 4.2 km/h, and as they tested each shoe, the contact area, maximum pressure average, and surface force were all measured. Results : Shoe Type A showed a contact area of $148.78{\pm}4.31cm^2$, Type B showed an area of $145.74{\pm}4.1cm^2$, and Type C showed an area of $143.37{\pm}4.57cm^2$ (p<.01). Shoe Type A demonstrated a maximum average pressure of $80.80{\pm}9.92kPa$, Type B an average of $85.72{\pm}11.01kPa$, and Type C an average of $89.12{\pm}10.88bkPa$ (p<.05). Shoe Type A showed a ground reaction force of $1.13{\pm}0.06%BW$, Type B a force of $1.16{\pm}0.04%BW$, and Type C a force of $1.16{\pm}0.03%BW$ (p<.05). Conclusion : The Type A trail-walking shoe, which was designed with a wide arch from the center of the forefoot to the front of the rearfoot showed excellent performance, however, more development and analysis of the windlass mechanism for a variety of arch structures is still necessary.

• Korean Journal of Applied Biomechanics
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• v.25 no.1
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• pp.103-111
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• 2015

Objective : The purpose of this study was to evaluate the effect for running shoes with resilience of midsole on biomechanical properties. Methods : 10 healthy males who had no history of injury in the lower extremity with an average age of 26.5 year(SD=1.84), height of 172.22 cm(SD=4.44) and weight of 67.51 kg(SD=6.17) participated in this study. All subjects ran on the treadmill wearing three different running shoes. Foot pressure data was collected using Pedar-X system(Novel Gmbh, Germany) operating at 100 Hz. Surface EMG signals for biceps femoris, rectus femoris, vastus lateralis, medial lateralis, tibialis anterior, medial gastrocnemius, soleus and peroneus longus were acquired at 1000 Hz using Bignoli 8 System(Delsys Inc., USA). To normalize the difference of the magnitude of muscle contractions, it was expressed as a percentage relative to the maximum voluntary contraction (MVC). The impact resilience of the midsole data was collected using Fastcam SA5 system(Photron Inc., USA). Collected data was analyzed using One-way ANOVA in order to investigate the effects of each running shoes. Results : TPU midsole was significantly wider in contact area than EVA, TPE midsole in midfoot and higher in EMG activity than EVA midsole at biceps femoris. TPE midsole was significantly wider in contact area than EVA midsole in rearfoot and higher in peak pressure than EVA midsole in forefoot. EVA midsole was significantly higher in EMG activity than TPU midsole at tibia anterior. In medial resilience of midsoles, TPE midsole was significantly higher than EVA, TPU midsole. Conclusion : TPU midsole can reduce the load on the midfoot effectively and activate tibialis anterior, biceps femoris to give help to running.

• The Journal of Korean Physical Therapy
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• v.30 no.4
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• pp.141-145
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• 2018

Purpose: Changes in the curvature of the vertebral columns of elderly women with increasing age causes various side effects and disorders. Therefore, this study was conducted to evaluate the effectiveness of the 8-figure scapular brace to improve pulmonary function and balance ability based on lung capacity and foot pressure by increasing the vertebral curvature. Methods: Seventeen elderly women with a forward head posture were selected. Women were asked to wear the 8-figure scapular brace and the forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) were measured, as were changes in foot pressure. Measurements were conducted three times each and the mean values were used for subsequent analyses. For static evaluation, we used the paired t-test to identify differences between pre and post values. Results: There was no significant difference in FEV1 and FVC before and after use of the brace (p>0.05); however, there was a significant decrease in forefoot pressure and an increase in rearfoot pressure following application of the brace (p<0.05). Conclusion: Application of the 8-figure scapular brace to correct vertebral curvature in elderly women influenced pressure distribution change from immediate effect body arrange of cervical and thoracic. However, wearing the 8-figure scapular brace may interfere with expansion of the chest and therefore respiratory muscle activity. Accordingly, it is necessary to apply appropriate treatment when wearing a scapular brace and to allow a sufficient intervention period while also providing therapeutic interventions such as posture correction or respiration training.

• Journal of Korean Foot and Ankle Society
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• v.8 no.1
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• pp.64-70
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• 2004

Purpose: We compared the result of a proximal metatarsal closed wedge osteotomy and soft tissue procedure with a modified chevron osteotomy and soft tissue procedure in the treatment of hallux valgus. Materials and Methods: Between March 1999 and February 2003, we performed proximal metatarsal closed wedge osteotomy and soft tissue procedure on 17 feet (12 patients), and modified chevron osteotomy and soft tissue procedure on 12 feet (9 patients). Results: According to Mayo clinic forefoot scoring system (FFSS), group 1, with proximal metatarsal closed wedge osteotomy, shows 67.2 points postoperatively and group 2, with modified chevron osteotomy, shows 68.5 points postoperatively. In group 1, the average correction of hallux valgus angle and intermetatarsal angle was 20.8 degrees and 4.8 degrees, respectively. In group 2, the average correction of hallux valgus angle and intermetatarsal angle was 19.9 degrees and 4.7 degrees, respectively. The average shortening was 3.15 mm in group 1 and 1.38 mm in group 2. Conclusion: We obtained relatively good clinical and radiographic result in this study. The effect on shortening of the first metatarsal was greater in the proximal metatarsal closed wedge osteotomy than modified chevron osteotomy, but the metatarsal shortening did not related with metatarsalgia. So, both techniques seems optimal surgical treatment for hallux valgus deformity.

• Journal of Korean Foot and Ankle Society
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• v.11 no.1
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• pp.1-7
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• 2007

Purpose: Tumors arising in the foot and ankle are uncommon and the malignant tumors are known to be rare compared with those of the other sites. We analyzed the clinical data of patients who have been diagnosed as having a tumor of the foot and ankle. Materials and Methods: From 1989 to 2006, we analyzed 185 patients who have been treated surgically and were pathologically confirmed of having tumors of the foot and ankle. Their clinical characteristics were reviewed retrospectively. Results: One hundred and fifty-seven cases were benign (84.9%) and 28 cases (15.1%) were malignant. 108 cases (58.4%) were benign soft tissue tumors and 49 cases (26.5%) were benign bone tumors. Malignant tumors included 17 cases (9.2%) of soft tissue tumors, 8 cases (4.3%) of primary bone tumors and 3 cases (1.6%) of metastatic bone tumors. The most common benign soft tissue tumor was ganglion (23 cases). Enchondroma (9 cases) was the most common among the benign bone tumors. Malignant peripheral nerve sheath tumor was the most common malignant tumor (4 cases). The predilection site for benign tumors was at the forefoot around toes while for the malignant tumor was around the ankle. 4.6% of benign soft tissue tumors and 8.2% of benign bone tumors had locally recurred and 14 cases (50%) of malignant tumor were confirmed as having distant metastasis. Conclusion: The ratio of malignant tumor and its metastasis rate was high. Therefore, the histopathologic confirmation is essential when treating tumors of the foot and ankle.

• Physical Therapy Korea
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• v.15 no.4
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• pp.1-9
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• 2008

The purpose of this study was to assess the peak plantar pressure distribution under foot areas according to the height of heel lifts in obese adults and non-obese adults during walking. Thirty-one participants volunteered for this experiment. The average body mass index (BMI) value of the fourteen subjects in the obese group was $26.5{\pm}1.4kg/m^2$ (from 25.1 to 29.3 $kg/m^2$), and of seventeen subjects in the non-obese group was $20.0{\pm}1.1kg/m^2$ (from 18.7 to 22.7 $kg/m^2$). The subject ambulated while walking in the sneakers, walking with 2 cm heel lifts, and walking with 4 cm heel lifts in the shoes. We measured the peak plantar pressure under the hallux, 1st, 2nd, 3~4th, and 5th metatarsal head (MTH), mi foot, and heel using F-scan system. The obese group had significantly higher peak plantar pressure under all foot areas than the non-obese group regardless of the height of heel lifts (p<.05). The peak plantar pressure under the 5th MTH and heel was significantly decreased, also the peak plantar pressure under hallux, 1st, and 2nd MTH was significantly increased according to the height of heel lifts in the obese group and non-obese group (p<.05), We proposed that individuals with heel lifts in shoes should be careful, as there is high plantar pressure under the forefoot.