• Korean Journal of Applied Biomechanics
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• v.31 no.2
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• pp.113-118
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• 2021

Objective: The purpose of this study was to investigate differences of landing strategy between people with or without chronic ankle instability (CAI) during double-leg drop landing. Method: 34 male adults participated in this study (CAI = 16, Normal = 18). Participants performed double-leg drop landing task on a 30 cm height and 20 cm horizontal distance away from the force plate. Lower Extremities Kinetic and Kinematic data were obtained using 8 motion capture cameras and 2 force plates and loading rate was calculated. Independent samples t-test were used to identify differences between groups. Results: Compared with normal group, CAI group exhibits significantly less hip internal rotation angle (CAI = 1.52±8.12, Normal = 10.63±8.44, p = 0.003), greater knee valgus angle (CAI = -6.78±5.03, Normal = -12.38 ±6.78, p = 0.011), greater ankle eversion moment (CAI = 0.0001±0.02, Normal = -0.03±0.05, p = 0.043), greater loading Rate (CAI = 32.65±15.52, Normal = 18.43±10.87, p = 0.003) on their affected limb during maximum vertical Ground Reaction Force moment. Conclusion: Our results demonstrated that CAI group exhibits compensatory movement to avoid ankle inversion during double-leg drop landing compared with normal group. Further study about how changed kinetic and kinematic affect shock absorption ability and injury risk in participants with CAI is needed.

• Korean Journal of Applied Biomechanics
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• v.32 no.1
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• pp.9-16
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• 2022

Objective: The purpose of this study was to investigate how the chronic ankle instability affects postural control during forward jump landing. Method: 20 women with chronic ankle instability (age: 21.7 ± 1.6 yrs, height: 162.1 ± 3.7 cm, weight: 52.2 ± 5.8 kg) and 20 healthy adult women (age: 21.8 ± 1.6 yrs, height: 161.9 ± 4.4 cm, weight: 52.9 ± 7.2 kg) participated in this study. For the forward jump participants were instructed to stand on two legs at a distance of 40% of their body height from the center of force plate. Participants were jump forward over a 15 cm hurdle to the force plate and land on their non-dominant or affected leg. Kinetic and kinematic data were obtained using 8 motion capture cameras and 1 force plates and joint angle, vertical ground reaction force and center of pressure. All statistical analyses were using SPSS 25.0 program. The differences in variables between the two groups were compared through an independent sample t-test, and the significance level was to p < .05. Results: In the hip and knee joint angle, the CAI group showed a smaller flexion angle than the control group, and the knee joint valgus angle was significantly larger. In the case of ankle joint, the CAI group showed a large inversion angle at all events. In the kinetic variables, the vGRF was significantly greater in the CAI group than control group at IC and mGRF. In COP Y, the CAI group showed a lateral shifted center of pressure. Conclusion: Our results indicated that chronic ankle instability decreases the flexion angle of the hip and knee joint, increases the valgus angle of the knee joint, and increases the inversion angle of the ankle joint during landing. In addition, an increase in the maximum vertical ground reaction force and a lateral shifted center of pressure were observed. This suggests that chronic ankle instability increases the risk of non-contact knee injury as well as the risk of lateral ankle sprain during forward jump landing.

• Korean Journal of Applied Biomechanics
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• v.34 no.2
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• pp.93-103
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• 2024

Objective: The purpose of this study was to investigate whether dancers with chronic ankle instability (CAI) exhibit different characteristics in dynamic postural control ability and ankle joint laxity compared to dancers without CAI and non-dancers with CAI. Method: Twelve dancers with CAI, 14 dancers without CAI, and 12 non-dancers with CAI participated in the study. Dynamic balance was evaluated using the Star Excursion Balance Test (SEBT) and the single-leg hop balance. The laxity of the ankle joint was evaluated through the anterior drawer test and the talar tilt test. SEBT measured maximum reach distances in anterior, posteromedial, and posterolateral directions. Single-leg hop assessed center of pressure (COP) and time-to-boundary (TTB) outcomes. One-way ANOVA and Chi-square tests were performed to compare the outcome variables among the three groups. Results: Dancers with CAI demonstrated greater reach distance in the posterolateral direction compared to non-dancers with CAI during SEBT (p=.014). Secondly, dancers without CAI showed greater reach distance in the posterolateral (p<.001) and posteromedial (p=.001) directions during SEBT compared to non-dancers with CAI. Additionally, dancers without CAI exhibited better postural control with higher TTB AP mean of minima (p=.003) and TTB AP standard deviation of minima (p=.012) during single-leg hop compared to nondancers with CAI. Thirdly, dancers with CAI showed a lower positive rate during the anterior drawer test compared to non-dancers with CAI (p=.019). Conclusion: Dancers with CAI demonstrated better ankle function and reduced mechanical instability compared to non-dancers with CAI. Therefore, to elucidate the underlying mechanisms of lateral ankle sprain and CAI development exacerbation in dancers, additional factors that can affect ankle sprain, such as visual dependence during postural control and evaluation in dance movements, should be explored.

• Korean Journal of Applied Biomechanics
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• v.31 no.3
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• pp.168-175
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• 2021

Objective: To investigate the static and dynamic analysis of ankle joint complex between subjects with chronic ankle instability (CAI) and healthy controls. Method: A total of 38 subjects and CAI group (N=19) and healthy control (N=19) participated in this first study. Variables that were measured in this study were as follows: 1) Subtalar joint axis inclination and deviation 2) Rearfoot angle 3) Navicular drop test 4) Heel alignment view in alignment analysis. Intra Correlation Coefficient (ICC) is used for reliability. A secondary 17 subjects are recruited including 9 of CAI and healthy for gait analysis between group. Lower extremity sagittal, frontal, and transverse kinematics were measured. All data were analyzed to ensemble curve analysis. Results: 1) There were statistically significant differences in standing rearfoot, navicular drop, heel alignment view, subtalar joint (STJ) inclination and deviation. 2) Only in sagittal, meaningful difference is showed during walking in gait analysis. Conclusion: Morphological problem can affect ankle sprain in aspect of structure with no relation to compensation of neuromuscular.

• The Journal of Korean Physical Therapy
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• v.28 no.6
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• pp.376-380
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• 2016

Purpose: This study was to investigate the short-term effects of spiral taping (ST) on performance on the star excursion balance test (SEBT) in individuals with unilateral chronic ankle instability (CAI). Methods: This study was single-group pre - post measures experimental design. The subjects with CAI were 39 (range, 20-31 years; male 16, females 23) were enrolled in the study. The discomfort had in unilateral ankle and Cumberland ankle instability score was 19.56 (${\pm}3.29$). Spiral tape (a width of 3 mm) was applied $3{\times}4$ cross shape on medial malleolus, lateral malleolus and dorsal of talocural joint of unstable ankle. SEBT was measured baseline and 30 min later in stable ankle and unstable ankle. Results: SEBT showed significantly improved after applying the ST (p<0.05, ES=0.74) on unstable ankle. In comparison the difference of stable and unstable ankle, between the pretest and posttest were significant differences (p<0.01, ES=1.88). Conclusion: These results indicated that ST improves performance on the SEBT. Therefore, it suggests that ST may be a suitable intervention to dynamic balance in patients with CAI.

• 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.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.3
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• pp.49-59
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• 2024

Purpose : Chronic ankle instability (CAI) can impair strength and balance, leading to activity limitations and restricted participation. Traditionally, ankle stabilization exercises have been applied, and more recently, the effects of hip muscle exercises have been studied. The purpose of this study was to determine the immediate effects of hip exercises (HE) and ankle stabilization exercises (ASE) on dynamic balance, performance and ankle function in subjects with CAI. We also compared the difference in effectiveness between HE and ASE. Methods : A total of 34 subjects with CAI participated, ane were randomly divided into two groups: the HE group and the ASE group. The HE group performed a program consisting of exercises above 70 % MVIC, while the ASE group performed a traditional ankle stabilization exercise program. The subjects in each group completed their respective exercise program for a total of 30 minutes once a day and were assessed before and after the intervention. Dynamic balance was assessed using the Y-balance test (YBT). Performance was assessed using the hop for distance test (HDT), and side-hop test (SHT). Ankle function was assessed using foot and ankle ability measure (FAAM) questionnaires. Results : YBT, HDT, and FAAM values increased significantly in both groups after the intervention (p<.05), and there was no significant difference between the groups. SHT values decreased significantly in both groups after the intervention (p<.05), and there was no significant difference between the groups. Conclusion : Although no significant superiority was observed between HE and ASE in this study, both exercise programs were effective in improving dynamic balance, performance, and ankle function in subjects with CAI. These findings suggest that both HE and ASE can be suitable interventions for CAI, highlighting the need for individualized treatment plans. Future research is warranted to explore the long-term effects of exercise programs on CAI subjects of different ages and occupational characteristics.

• Journal of the Korean Applied Science and Technology
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• v.40 no.6
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• pp.1259-1267
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• 2023

The purpose of this study was to investigate the effects of a acute ankle mobility exercise (AE) program on the range of motion and pain levels associated with chronic ankle instability (CAI). Twenty adult women with an average score of 24 or less on both sides in the ankle instability questionnaire were selected and divided into two groups: the Ankle Mobility Exercise Program group (AE, n=10) and the control group (CON, n=10). The AE treatment involved a one-time, 20-minute exercise session for each ankle, conducted separately on the left and right ankles, to examine the response to a acute exercise. Measures of ankle instability, pain, and ankle range of motion were evaluated before and after the treatment. In the AE group, which underwent the AE program, a significant decrease in pain was observed post-AE compared to pre-AE (p<.01). In addition, an increase in dorsiflexion was observed in the AE group post-AE compared to pre-AE following the AE program(p<.05). These results suggest that a acute AE program can effectively alleviate some aspects of ankle instability by improving ankle pain and range of motion in adult women with chronic ankle instability (CAI).

• Journal of Korean Foot and Ankle Society
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• v.14 no.2
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• pp.123-129
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• 2010

Purpose: To evaluate the efficacy of the arthroscopic exploration combined with modified Brostrom operation (MBO) for the treatment of chronic lateral ankle instability (CAI). Materials and Methods: Sixty patients who diagnosed a CAI were performed MBO. We divided to 2 groups, whether simultaneously inspected by arthroscopy (group B) or not (group A). The both group's results were compared according to American Orthopedic Foot and Ankle Society Ankle-hindfoot score (AOFAS), functional ankle score and visual analog scale (VAS) at preoperative and final follow-up period. Results: There were no significant differences of AOFAS, functional ankle score and VAS between both groups at final follow-up. However, in group A, 2 cases associated with medial ankle instability and syndesmotic injuries were did not diagnosed preoperatively, showed poor prognosis. In group B, one case had a permanent peroneal nerve symptom. The match rate of intra-articular lesions between preoperative diagnosis and postoperative arthroscopic diagnosis was 30% in group B. Conclusion: Combination of arthroscopic exploration and MBO is effective strategy for intra-operatively discrimination of intra-articular associated lesions for CAI.

• The Journal of Korean Physical Therapy
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• v.34 no.3
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• pp.91-97
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• 2022

Purpose: This study investigated the short-term effectiveness of extracorporeal shock wave therapy (ESWT) on pain, the ankle instability, the ankle function, dorsiflexion range of motion (ROM), and dynamic balance in patients with chronic ankle instability (CAI). Methods: Eighteen participants were divided into an experimental (n=9) and control group (n=9). The ESWT in the experimental group was applied to the lateral collateral ligament in combination with the tibialis anterior whereas the ESWT was applied to the lateral collateral ligament of the ankle alone in the control group. Pain, the ankle instability, the ankle function, dorsiflexion ROM, and dynamic balance were measured using the Visual analog scale, Cumberland ankle instability tool, American Orthopedic Foot and Ankle Society ankle-hindfoot score, weight-bearing lunge, and Y-balance test, before and after ESWT intervention. Results: Significant interactions (group × time) and time effects were observed in the dorsiflexion ROM and dynamic balance. Bonferroni's post-hoc analysis showed that the experimental group revealed a more significant change in dorsiflexion ROM and dynamic balance than the control group. There was a significant time effect in the pain, the ankle instability, and the ankle function, but no significant interaction (group × time) was observed. Conclusion: The ESWT could improve the pain, ankle instability, ankle function, dorsiflexion ROM, and dynamic balance in patients with CAI. Furthermore, the ESWT combined with lateral ankle ligaments and tibialis anterior more improves the dorsiflexion ROM and dynamic balance.