Purpose: Although postural control assessment in patients with chronic ankle instability (CAI) has been thoroughly examined in the literature, few researchers have studied balance strategy in lateral ankle sprain (LAS) copers, who recover from LAS injury with no symptom progression. The purpose of this study was to investigate the difference in center of pressure (COP) variables during static and dynamic posture control among LAS copers, patients with CAI, and ankle healthy controls. Methods: This case-control study recruited 20 patients with CAI, 20 LAS copers, and 20 controls. All participants filled out Ankle Instability Instrument and Foot and Ankle Ability Measure questionnaire and performed single-leg static postural control and Star Excursion Balance Test (SEBT). Results: LAS copers showed less mediolateral COP range as compared to patients with CAI (p=0.001) and control (p=0.001) during static postural control. Furthermore, LAS copers have less anteroposterior COP standard deviation (SD) (p=0.034), range (p=0.009), velocity (p=0.013) than patients with CAI. Relative to patients with CAI, LAS copers had small mediolateral COP SD (p=0.022) and range (p=0.018) during the posteromedial direction of the SEBT.However, there was no significant difference in both mediolateral and anteroposterior COP variables during anterior and posterolateral directions of the SEBT (p≥ 0.05). Conclusion Based on these observed results, the authors conclude that greater postural control in LAS copers is one of the movement strategies to prevent recurrent LAS as a defense mechanism.

Purpose: This study aimed to compare a dynamic neuromuscular training program with a static neuromuscular training program for taekwondo players. Methods: This study design was a randomized control trial. Three high school taekwondo teams (taekwondo neuromuscular training [TNT] group, 22; Get Set group, 17; and control group, 24) participated in the study. Get Set group performed a program focused on the static movement, and TNT group performed a program which was modified Get Set to dynamic movement. Control group maintained the existing taekwondo training without any intervention. The intervention group performed 15-minute training three times a week for 6 weeks. Dynamic Postural Stability Index (DPSI) and time-to-boundary test (TTB) tests were performed before and after 6 weeks of training. Results: As a result of DPSI, an interaction effect was observed only in the anterior/posterior stability index of the dominant leg of the TNT and Get Set groups (p＜0.05). However, there was no difference between the TNT and the Get Set groups.As a result of TTB analysis, no statistical effect was observed in all variables of the dominant and non-dominant legs. Conclusion As a result of conducting 6-week dynamic and static neuromuscular training for taekwondo athletes, the effect of training was found in both the intervention group. However, differences in training effects between groups could not be proved. Therefore, it is necessary to clearly confirm the difference between the two training through long-term follow-up studies.

BACKGROUND AND OBJECTIVES : Ageotrophic nystagmus in the horizontal canal BPPV has been explained as a result of cupulolithiasis theory, and has been reported to have the less therapeutic response to conservative rehabilitations than the other type BPPV . Though methods to detach the debris with vibrator have been introduced, the effect has been questioned and it's not physiologic. MATERIALS AND METHOD : We introduce a new head shaking-forced prolonged position method as a more convenient method, and report typical 2 cases of ageotrophic horizontal canal BPPV managed with it and analyzed results of 25 cases all told. RESULTS AND CONCLUSION : The average number of rehabilitation was less than two, and loss of direction changing positional nystagmus could be observed immediately after rehabilitation.
Head ; Nystagmus, Physiologic ; Rehabilitation ; Vertigo*

BACKGROUND AND OBJECTIVES: Canalith repositioning procedure (CRP) is an effective treatment for benign paroxysmal positional vertigo (BPPV). However, there is a significant number of patients who require multiple treatment visits for reliefs of symptoms. The purpose of this study is to identify factors that may be associated with these difficult to treat cases. MATERIALS AND METHODS: A retrospective review was made of 179 patients who were diagnosed as BPPV. 20 patients who required more than three treatment visits for CRP were included in this study. Statistical analysis included age and sex of patients, the kind of involved semicircular canal (SCC), direction of nystagmus, latency of nystagmus on electronystagmography (ENG) and duration of symptoms. RESULTS: There was no significant statistical association between the number of treatment visit and patient's age, sex. Although significant statistical association was not found, the therapeutic efficacy of lateral SCC BPPV was lower than that of posterior SCC BPPV. In the cases where the direction of nystagmus was ageotrophic, the efficacy of CRT was decreased and statistical significant association was found. Also when short latency of nustagmus on ENG and long duration of symptoms appeared, more trial of CRP was needed and statistical significant association was found. CONCLUSION: In the treatment of BPPV by CRP, we can consider latency of nystagmus on ENG, duration of symptoms, direction of nystagmus and type of involved semicircular canal as prognostic factors.
Electronystagmography ; Humans ; Rehabilitation* ; Retrospective Studies ; Semicircular Canals ; Vertigo*

Purpose: This study aimed to analyze the profiles and mechanisms of injuries using online injury surveillance system (OISS) with match video files at 2017 World Taekowndo Championship (WTC) athletes. Methods: This study design was a prospective epidemiological study with video analysis. All injuries were recorded during the 2017 WTC using the OISS developed by the International Olympic Committee. A total of 971 athletes who participated in the 2017 WTC were enrolled. Each injury was recorded retrospectively by three cameras surrounding each court. Injury profiles and mechanisms were calculated as; percent injury rate, injury rate/100 athlete-exposures, injury location, type, and mechanism via the injury surveillance system and video analysis form. Results: There were 74 injuries, which corresponded to an overall incidence of 13.5 injuries (95% confidence interval, 11.2–15.8) per 100 athletes. The face (27.0%), hand/finger (23.0%), knee (14.9%), and ankle (10.8%) were most frequently injured parts. Contusions (37.8%), fracture and ligament sprains (20.3%) were the most frequently injury types. The main mechanism for contact injury is while attacking with the roundhouse kick (66.2%), or not used block (81.1%). There were also noncontact injuries (24.3%). Conclusion The incidence of injuries to the face, hand/fingers, knee, and ankle was relatively high. To prevent contact injuries, protective headgear and better shin guards and hand protectors need to be developed. As for the noncontact injuries, we recommend hamstring strengthening exercises, and neuromuscular training to strengthen the tendons and ligaments protecting the ankle and knee joints.