• Clinics in Orthopedic Surgery
• /
• v.10 no.4
• /
• pp.479-483
• /
• 2018

Background: We developed a modified proximal scarf osteotomy technique for moderate to severe hallux valgus in an attempt to obtain better correction of the deformity. In addition, we compared the clinical and radiographic results of this modified technique with those of the classic scarf osteotomy reported in other studies. Methods: Between December 2004 and July 2009, 44 cases of modified proximal scarf osteotomy was performed in 35 patients with moderate hallux valgus. The American Orthopedic Foot and Ankle Society (AOFAS) score, visual analogue scale (VAS) score, range of motion of the first metatarsophalangeal joint, and radiographic results were evaluated. Results: The mean hallux valgus angle and the mean first intermetatarsal angle improved from an average of $32.2^{\circ}$ and $14.3^{\circ}$, respectively, to an average of $12.5^{\circ}$ and $8.6^{\circ}$, respectively. The distal metatarsal articular angle improved from an average of $18.7^{\circ}$ to $12.4^{\circ}$. The preoperative mean AOFAS and VAS scores were 47 points and 7 points, respectively, which improved to 86 points and 1 point, respectively, at the final follow-up. Limited range of motion occurred in two cases postoperatively. The height of the first metatarsal-cuneiform joint, which was an average of 15.9 mm preoperatively, did not change. The first metatarsal-talus angle increased from an average of $4.1^{\circ}$ to $7.1^{\circ}$. Conclusions: The modified proximal scarf osteotomy for the treatment of moderate hallux valgus showed similar results with the classic scarf osteotomy with regard to changes in the first intermetatarsal angle and postoperative satisfaction. Therefore, we suggest the modified proximal scarf osteotomy be considered as well as other proximal osteotomy in the treatment of moderate to severe hallux valgus.

• Transactions of the KSME C: Technology and Education
• /
• v.1 no.2
• /
• pp.153-165
• /
• 2013

The established gait analysis studies have regarded leg as one single spring. If we can design a knee-ankle actuating mechanism as a primary actuator for supporting knee extension, it might be possible to revolutionary store or release elastic strain energy, which is consumed during the gait cycle, and as a result leg stiffness is expected to increase. An ankle joint actuating mechanism that stores and releases the energy in ankle joint is expected to support and solve excessive artificial leg stiffness caused by the knee actuator (primary actuator) to a reasonable extent. If unnecessary kinematic energy is released with the artificial speed reduction control designed to prevent increase in gait speed caused by increase in time passed, it naturally brings question to the effectiveness of the actuator. As opposed to the already established studies, the authors are currently developing knee-ankle two actuator system under the concept of increasing lower limb stiffness by controlling the speed of gait in relative angular velocity of the two segments. Therefore, the author is convinced that compensatory mechanism caused by knee actuating must exist only in ankle joint. Ankle joint compensatory mechanism can be solved by reverse-examining the change in metatarso-phalangeal joint (MTPJ) tilt angle (${\theta}_1=0^{\circ}$, ${\theta}_2=17^{\circ}$, ${\theta}_3=30^{\circ}$) and the effect of change in gait speed on knee activity.

• Journal of Korean Foot and Ankle Society
• /
• v.1 no.1
• /
• pp.11-14
• /
• 1997

Hallux valgus is a complex deformity which contains static subluxation of the first metatarsophalangeal joint with lateral deviation of the great toe and medial deviation of the first metatarsal bone. Among the several parameters, radiographic indices are the important ones in the choice of the treatment method. Even though, the normal values of the western peoples are already estabilished, there was no standard values for Korean who has different genetics, and cultural background, till now. So, we tried to estimate the noraml values of the HVA (hallux valgus angle ), IMA ( Intermetatarsal angle) and DMAA (Distal Metatarsal Articular surface Angle) in a normal adult. Fifty normal adult (each 25 male and female) were chosen and took 100 cases of foot radiograph and radiologic indices of the hallux valgus were measured. Average age at the investigation was 34.5 years old. The average HVA is $13.3^{\circ}$, IMA is $8.5^{\circ}$ and DMAA is $34.6^{\circ}$.

• Korean Journal of Applied Biomechanics
• /
• v.27 no.3
• /
• pp.189-195
• /
• 2017

Objective: The aim of this study was to examine the effect of foot landing type (forefoot vs. rearfoot landing) on kinematics, kinetics, and energy absorption of hip, knee, and ankle joints. Method: Twenty-five healthy men performed single-leg landings with two different foot landing types: forefoot and rearfoot landing. A motion-capture system equipped with eight infrared cameras and a synchronized force plate embedded in the floor was used. Three-dimensional kinematic and kinetic parameters were compared using paired two-tailed Student's t-tests at a significance level of .05. Results: On initial contact, a greater knee flexion angle was shown during rearfoot landing (p < .001), but the lower knee flexion angle was found at peak vertical ground reaction force (GRF) (p < .001). On initial contact, ankles showed plantarflexion, inversion, and external rotation during forefoot landing, while dorsiflexion, eversion, and internal rotation were shown during rearfoot landing (p < .001, all). At peak vertical GRF, the knee extension moment and ankle plantarflexion moment were lower in rearfoot landing than in forefoot landing (p = .003 and p < .001, respectively). From initial contact to peak vertical GRF, the negative work of the hip, knee, and ankle joint was significantly reduced during rearfoot landing (p < .001, all). The contribution to the total work of the ankle joint was the greatest during forefoot landing, whereas the contribution to the total work of the hip joint was the greatest during rearfoot landing. Conclusion: These results suggest that the energy absorption strategy was changed during rearfoot landing compared with forefoot landing according to lower-extremity joint kinematics and kinetics.

• Korean Journal of Applied Biomechanics
• /
• v.14 no.3
• /
• pp.17-35
• /
• 2004

The purpose of this study is to explain developmental process of gait via angle-angle diagram to understand how coordinated relationships and control change with age. Twenty four female children, from one to five years of age were the test subjects for this study, and their results were compared to a control group consisting of twenty one adult females. The Vicon 370 CCD camera, VCR, video timer, monitor, and audio visual mixer was utilized to graph the gait cycle for all test subjects. Both coordinated Intra-limb relationships, and range of motion and timing according to quadrant were explained through the angle angle diagram. Movement in the sagittal plane showed both coordinated relationships and control earlier than movement in the coronal or transverse plane. In the sagittal plane, hip and Knee coordinated relationships developed first (from one year of age.) Coordinated relationships in the Knee and ankle and hip and ankle developed next, respectively. Both hip and ankle and knee and ankle development were inhibited by the inability of children to completely perform plantar flexion during the swing and initial double limb support phases. Children appeared to compensate for this by extending at their hip joint more than adults during the third phase, final double limb support. In many cases the angle angle diagram for children had a similar shape as adult's angle angle diagram. This shows that children can coordinate their movements at an early age. However, the magnitudes and timing of children's angle angle diagrams still varied greatly from adults, even at five years of age. This indicates that even at this age, children still do not possess full control of their movements.

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

• Journal of Korean Foot and Ankle Society
• /
• v.19 no.4
• /
• pp.171-175
• /
• 2015

Purpose: Tibiotalocalcaneal arthrodesis has been used as a treatment option for severe deformity including Charcot arthropathy, avascular necrosis of the talus, and severe osteoarthritis of the ankle and subtalar joint. The purpose of this study was to evaluate the result of the surgical outcome of tibiotalocalcaneal arthrodesis using a retrograde intramedullary nail. Materials and Methods: Tibiotalocalcaneal arthrodesis using a retrograde intramedullary nail was performed by one surgeon in 36 cases. Clinical and radiological finding was evaluated using assessment of fusion time, 5th metatarsal-tibial angle, possibility of postoperative complication, visual analogue scale for pain and American Orthopaedic Foot and Ankle Society (AOFAS) score. Results: Union was achieved in 33 cases at an average of 23 weeks (11~29 weeks). There were 3 cases of nonunion and 1 case of reoperation. Nail-tibial angle tended to be larger in nonunion cases. AOFAS score showed significantly poor outcome at malalignment (${\geq}5^{\circ}$), negative value of 5th metatarsal-tibial angle. Conclusion: Tibiotalocalcaneal arthrodesis using a retrograde intramedullary nail is considered a useful treatment option for severe destruction and deformity involving ankle and subtalar joint.

• Physical Therapy Korea
• /
• v.23 no.1
• /
• pp.20-30
• /
• 2016

Background: Total knee arthroplasty (TKA) recovers the alignment of the knee joint, but fails to automatically restore the alignment and function of the hip and ankle joints. It may affect the alignment and stability of the knee joint, therefore therapeutic intervention in hip and ankle joint is necessary for the rehabilitation process after TKA. Objects: The aim of this study was to comparison of the effects of the two exercise methods on the coronal plane alignment after TKA. This study conducted an experiment by dividing subjects into a lower extremity isometric co-contraction group (LEIC) and a quadriceps isolated isometric contraction (QIIC) group. Methods: A total of 37 subjects were randomly assigned to the LEIC ($n_1$=19) or the QIIC ($n_2$=18). Exercise was applied to five times per week for three weeks, starting on the eighth day after surgery. Range of motion exercises were performed as a common intervention and then each group performed quadriceps isometric contraction exercises with 10 sets of 5 repetitions. Radiological imaging was performed prior to surgery, one month and six months after surgery. In addition, the hip-knee-ankle angle (HKA) and tibiotalar angle (TTA) were measured. Results: The HKA was close to neutral in the LEIC rather than the QIIC (p<.05). The LEIC showed varus and the QIIC exhibited valgus TTA (p<.05). In a comparison of HKA and TTA over time, there was no significant change in either group (p>.05). According to the comparison of the TTA before surgery, the LEIC showed significant changes in the varus direction (p<.05), while there was no significant change in the QIIC (p>.05). Conclusion: The LEIC method triggered changes in the TTA and brought the HKA close to the neutral. Thus, LEIC is more effective than QIIC in creating stability in the coronal plane alignment of the knee and ankle joints after TKA.

• Journal of Korean Foot and Ankle Society
• /
• v.28 no.2
• /
• pp.60-67
• /
• 2024

Purpose: Sinus tarsi syndrome (STS) is caused by various pathologies. However, the exact etiology of STS remains controversial. This study evaluated the imaging and arthroscopic findings of patients who underwent surgical treatment after conservative treatment for STS failed. Materials and Methods: Between December 2014 and August 2018, 20 patients (21 cases) who underwent surgical treatment for STS were included in the study. The clinical results were analyzed using the visual analog scale (VAS) and the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot functional scale. The radiographic results were analyzed using Meary's angle, calcaneal pitch angle, and hindfoot alignment angle. The pathologic conditions of sinus tarsi were confirmed by magnetic resonance imaging (MRI) and subtalar arthroscopy. Synovitis, bone edema, and accessory anterolateral talar facet (AALTF) were evaluated on MRI. Synovial thickening, cartilage damage, interosseous talocalcaneal ligament (ITCL) and cervical ligament rupture, soft tissue impingement, AALTF, and accessory talar facet impingement (ATFI) were evaluated by subtalar arthroscopy. Results: The mean duration of symptoms was 28.7 months (4~120). All patients showed significant improvement in the VAS and AOFAS ankle-hindfoot scale. Significant improvements in hindfoot alignment angle and Meary's angle postoperatively were noted in patients who underwent medial displacement calcaneal osteotomy. MRI confirmed synovitis in all patients, AALTF in 19 cases (90.5%), and ATFI with bone edema in seven cases (33.3%). In subtalar arthroscopy, pathologic conditions were observed in the following order: synovitis in 21 cases (100%), AALTF in 20 cases (95.2%), ITCL partial rupture in nine cases (42.9%), and soft tissue impingement in seven cases (33.3%). All cases had two or more pathological conditions, and 15 (71.4%) had three or more. Conclusion: In cases of STS that do not respond to conservative treatment, a comprehensive examination of the lesions of the tarsal sinus and lesions around the subtalar joint is essential.

• Korean Journal of Applied Biomechanics
• /
• v.27 no.3
• /
• pp.157-164
• /
• 2017

Objective: The purpose of this study was to investigate kinematic differences in back pike somersault in platform diving according to skill level and to apply the findings to improve performance. Method: Korean divers participating in this study were divided into a skilled group (age: $21.6{\pm}4.16y$, height: $1.68{\pm}0.03m$, weight: $62.0{\pm}3.94kg$, career: $12.6{\pm}5.13y$) and a less-skilled group (age: $20.6{\pm}2.7y$, height: $1.72{\pm}0.05m$, weight: $64.8{\pm}6.76kg$, career: $12.2{\pm}2.49y$) and an independent t-test was performed to analyze differences between groups at the moment of takeoff. Results: The two groups showed significant differences in displacement and velocity of center of mass (COM), takeoff angle, hip joint angle, knee joint angular velocity, and hip joint angular velocity at the takeoff (p<.05), and significant differences in displacement of COM, hip joint, and ankle joint during flight (p<.05). Conclusion: For a successful back pike, the COM should rise quickly in the vertical direction and the hip joint angle and angular velocity should increase. To improve performance, the back pike turn should be practiced on the ground before an attempt on a 10-m platform, to stretch the ankle and knee joints and enable quick flexion of the hip joint when turning in flight.