Background: Chronic ankle instability (CAI) is a prevalent condition among Taekwondo athletes, often associated with pain, psychological factors, and impaired physical performance. However, few studies have investigated the relationship among ankle muscle strength, pain, kinesiophobia, and physical performance in Taekwondo athletes with CAI. Objects: This study aimed to examine the relationship between ankle muscle strength, pain, kinesiophobia, and physical performance in Taekwondo athletes with CAI. Methods: Forty Taekwondo athletes with CAI participated in the study. Pain was assessed using the Visual Analogue Scale (VAS), and kinesiophobia was measured with the Tampa Scale for Kinesiophobia-11 (TSK-11). Physical performance was evaluated using the single-leg vertical jump (SLVJ) and single-leg hop for distance. The strength of the ankle muscles is measured using a Smart KEMA strength sensor. Pearson’s correlation coefficients were calculated to determine relationships among variables. Results: SLVJ showed a significant negative correlation with VAS (r = –0.506, p < 0.01) and a positive correlation with strength of the ankle inversion with dorsiflexion (IDF) (r = 0.356, p < 0.05). VAS was negatively correlated with strength of the ankle eversion with plantarflexion (r = –0.365, p < 0.05), IDF (r = –0.371, p < 0.05) and inversion with plantarflexion (r = –0.370, p < 0.05). No significant correlations were found between TSK-11 and physical performance, pain, or ankle muscle strength outcomes. Conclusion: Pain intensity and ankle muscle strength in specific ankle positions are associated with SLVJ in Taekwondo athletes with CAI. These findings suggest that the intensity of pain and the strength of the ankle evertor and invertor at specific ankle joint positions should be considered when evaluating Taekwondo athletes with CAI. Furthermore, managing pain and implementing strengthening exercises for the ankle evertor and invertor can be recommended to improve SLVJ.

Background: Nordic hamstring exercise (NHE) is a widely used eccentric strengthening exercise that reduces the risk of hamstring and anterior cruciate ligament injuries. During NHE, the ankles are fixed in a kneeling position, while the upper body falls forward as the knee extends, maximizing hamstring activation. However, compensatory movements, such as an increased hip joint angle, make optimal execution difficult. Assisted NHE (ANHE) using an elastic band facilitates controlled movement, maintains high hamstring activation, and allows intensity adjustments. Despite their benefits, research on exercise postures based on different elastic band application regions remains limited. Objects: This study aimed to compare trunk and hip extensors activation, the gluteus maximus vs. erector spinae (GM/ES) ratio, and subjective difficulty during NHE, chest-assisted NHE (C-ANHE), and pelvic-assisted NHE (P-ANHE). Methods: Twenty-two healthy males performed each exercise, starting from a kneeling position with the knee joint at 90° and extending 15° with isometric contraction. The muscle activations of the ES, GM, and the biceps femoris long head (BFlh) were measured using surface electromyography. The GM/ES ratio was calculated, and the Borg rating of perceived exertion (Borg RPE) (6–20) scale was examined. Results: ES (F = 141.38, p < 0.001), GM (F = 184.14, p < 0.001), and BFlh (F = 164.85, p < 0.001) activation differed significantly among the exercises. All muscles showed higher muscle activity during P-ANHE than during C-ANHE (p < 0.017). The GM/ES ratio was lower than 1 for all exercises but significantly higher in P-ANHE (0.66 ± 0.15) than in C-ANHE (0.57 ± 0.18) (p < 0.017). The Borg RPE score differed significantly among exercises (p < 0.001) and was higher in P-ANHE (15.10 ± 1.77) than in C-ANHE (11.86 ± 1.91) (p < 0.017). Conclusion: P-ANHE increased GM activation to a greater extent than C-ANHE, with moderate subjective difficulty. It is recommended as an ANHE variant for targeting the GM while considering ES activation.

Background: Decreased respiratory muscle strength in patients with stroke may cause breathing difficulties, and cardiopulmonary function and exercise capacity may decline, which may reduce balance and gait ability. Objects: This study aimed to determine the influence of improved respiratory muscle strength on the recovery of balance and gait ability at discharge in patients with stroke. Methods: This prospective observational study involved 21 patients clinically diagnosed with stroke. Multiple regression models with a forward selection procedure were used to investigate whether the improvement of respiratory muscle strength (maximal inspiratory pressure [MIP] and maximal expiratory pressure) can contribute to the recovery of balance (Trunk Impairment Scale, Berg Balance Scale, Brunel Balance Assessment, and five times sit-to-stand) and gait (10-meter walk test, timed up and go, and 6-minute walk test [6MWT]) ability. Results: In the forward selection regression analysis, MIP was an influencing factor, accounting for 36.2% of the variance in the 6MWT. Conclusion: This result suggests that an improvement in MIP influences the increase in distance in the 6MWT. Therefore, it is important to evaluate respiratory muscle strength. Inspiratory muscle strengthening can recommended improving endurance and functional walking ability in patients with stroke.

Ainsliaea acerifolia, a perennial herbaceous plant endemic to forested regions of the Korean Peninsula, has drawn attention for its bioactive properties and potential as a functional food and medicinal resource. Despite its ecological and economic value, little is known about its spatial distribution or habitat preferences under changing climatic conditions. This study aims to quantify the current and future habitat suitability of A. acerifolia in southeastern Korea—including Gyeongsangnam-do, Busan, and Ulsan—using the MaxEnt (Maximum Entropy) species distribution model. A total of 217 presence records were compiled from both GBIF data and field surveys, and seven key environmental variables were selected through multicollinearity screening. Model performance was robust (mean AUC = 0.845), and key predictors included topographic roughness (TRI), precipitation of the driest month (Bio14), and mean diurnal range (Bio2). Under current climate conditions, 31.5% of the study area was identified as suitable habitat (≥0.222), with only 4.7% categorized as core habitat (≥0.6). Future projections under SSP1-2.6, SSP2-4.5, and SSP5-8.5 scenarios indicated substantial habitat contraction, particularly in coastal and lowland areas, with refugial zones likely to persist in mid-elevation inland mountains (500–900 m). These findings suggest that A. acerifolia is highly sensitive to climatic variability and emphasizes the urgent need for conservation strategies focused on climate-resilient refugia and ecological corridors. The study provides a spatial framework for species conservation planning under future climate uncertainty.

본 연구는 비방사성 SrCl2를 이용하여 Sr 농도를 50, 100, 200mg·kg-1 및 토양 유기물 함량을 5%, 10% 및 15%로 달리하여 배추의 생육, 생체중, 엽록소 함량에 미치는 영향을 생육 시기별로 분석하였다. 그 결과, Sr 농도가 증가할수록 초장, 근장, 엽면적, 생체중 및 건물중이 유의하게 감소하였으며, 특히 Sr 200mg·kg-1 처리에서 생육 저 해가 뚜렷하였다. 반면, 엽록소 함량(SPAD)은 처리 간 유의한 차이를 보이지 않아 광합성 색소에는 Sr의 영향이 제 한적인 것으로 나타났다. 유기물 함량이 높은 토양에서는 Sr 처리에 따른 생육 저해가 완화되었으며, 특히 유기물 15% 조건에서 완충 효과가 가장 크게 나타났다. 이는 유기물이 Sr의 생물유효도를 감소시켜 식물체 흡수를 억제하 는 기작에 의한 것으로 판단된다. 본 연구는 비방사성 SrCl2를 이용한 실험을 통해 작물의 Sr 독성 반응과 유기물 기 반 토양 완충 효과를 정량적으로 규명하였으며, 향후 방사성 오염 토양의 생물학적 복원 및 안전 농산물 생산 전략 수립에 기초자료로 활용될 수 있다.