The Influence of Pronated Foot Posture on Knee Isokinetic Strength, Static and Dynamic Postural Stability in Healthy Young Individuals

Woochan Chun,Hee-su Kim,Sieun Park,Jihea Park,Seunghee Shim,Sookyoung Park 한국전문물리치료학회 2021 한국전문물리치료학회지 Vol.28 No.3

Background: The foot is a complex body structure that plays an important role in static and dynamic situations. Previous studies have reported that altered foot posture might affect knee joint strength and postural stability, however their relationship still remains unclear. Objects: The purpose of this study was to identify whether pronated foot posture has an influence on knee isokinetic strength and static and dynamic postural stability. Methods: Forty healthy young males aged 18 to 26 years were included. Foot posture was evaluated using the Foot Posture Index-6 (FPI-6), and the subjects were divided into two groups according to their FPI-6 scores: a neutral foot group (n = 20, FPI-6 score 0 to +5) and a pronated foot group (n = 20, FPI-6 score +6 or more). Biodex Systems 3 isokinetic dyna-mometer was used to evaluate knee isokinetic strength and hamstring to quadriceps ratio at three angular velocities: 60°/sec, 90°/sec, and 180°/sec. The static and dynamic postural stabil-ity in a single-leg stance under the eyes-open and eyes-closed conditions were measured with a Biodex Balance System. Results: There were no significant differences between the groups in knee isokinetic strength and static postural stability (p > 0.05), but there was a significant difference in the medial–lateral stability index (MLSI) for dynamic postural stability under the eyes-closed condition (p = 0.022). The FPI-6 scores correlated significantly only with the dynamic overall stability index (OSI) and the MLSI (OSI: R = 0.344, p = 0.030; MLSI: R = 0.409, p = 0.009) under the eyes-closed condition. Conclusion: Participants with pronated foot had poorer medial–lateral dynamic stability un-der an eyes-closed condition than those without, and FPI-6 scores were moderately positively correlated with dynamic OSI and dynamic MLSI under the eyes-closed condition. These results suggest that pronated foot posture could induce a change in postural stability, but not in knee isokinetic strength.

Comparison of Craniovertebral Angle and Muscle Properties after Smartphone Use in Healthy Individuals with and without Forward Head Posture

( Dongyoon Son ),( Woochan Chun ),( Sookyoung Park ) 대한통합의학회 2021 대한통합의학회지 Vol.9 No.4

Purpose : Forward head posture (FHP) is one of the most common postural malalignment of the cranio-cervical region. Previous studies have reported that FHP might affect both temporomandibular joint (TMJ) and cervical muscles, but still remains unclear. The purpose of this study was to compare the changes of craniovertebral angle (CVA) and muscle properties after smartphone use in healthy individuals with and without FHP. Methods : Fifteen healthy individuals aged 18 to 22 years were included. CVA was evaluated using Dartfish motion analysis, and the subjects were divided into two groups according to their CVA: a FHP group (n = 7, CVA less than 48 °) and a control group (n = 8, CVA more than 48 °). MyotonPro was used to measure muscle properties of masseter, digastric and sternocleidomastoid muscles (SCM). Each subject underwent 15-minutes of smartphone task (web browsing or video watching) in relaxed sitting posture. CVA and muscles properties were assessed both before and after the smartphone task. Results : There were significant changes in post measurements of CVA between the groups. Masseter muscle showed significant differences in pre and post measurements of all muscle properties, and digastric muscle showed significance only in muscle tone. Amount of changes (post-pre), however, showed no significant difference in this study. Conclusion : 15-minutes of smartphone task did not affect CVA and muscle properties of masseter, digastric and SCM in both groups, however, there were significant changes in pre and post measurements of CVA and some muscle properties of masseter and digastric muscles. Therefore, CVA, masseter and digastric muscles might be significantly changed in a heavy duration of smartphone usage more than 15-minutes. Further studies are needed regarding duration of smartphone task, assessments in other various TMJ muscle groups, and participants with pathological FHP conditions.

응급실 손상환자 심층조사 자료를 이용한 2017-2018년 중독 환자의 분석

고지윤 ( Jiyoon Koh ),전우찬 ( Woochan Jeon ),강형구 ( Hyunggoo Kang ),김양원 ( Yang Weon Kim ),김현 ( Hyun Kim ),오범진 ( Bum Jin Oh ),이미진 ( Mi Jin Lee ),전병조 ( Byeong Jo Chun ),정성필 ( Sung Phil Chung ),김경환 ( Kyung Hwa 대한임상독성학회 2020 대한임상독성학회지 Vol.18 No.2

Purpose: The annual statistics for poisoning are reported based on the data from poison control centers in many advanced countries. In 2016 a study was conducted to analyze the 2016 Korea Poisoning status. This study was conducted to make a better annual report for poisoning statistics in Korea from a 2017-2018 national representative database. Methods: This study was a retrospective analysis of poisoning patients based on the data from an emergency department (ED) based injury in-depth surveillance project by the Korea Centers for Disease Control and Prevention in 2017-2018. Bite or sting injuries were not included. Results: A total of 17714 patients presented to 23 EDs because of poisoning. Adults above 20 years old age accounted for 84.6% of the population, while the proportion of intentional poisoning was 60.8%. The poisoning substance presented in the ED were therapeutic drugs (51.2%), gas (20.3%), pesticides (16.4%), and artificial substances (11.4%). Overall, 35% of patients were admitted for further treatment. The mortality was 2.4% (422 cases), and the most common fatal substances in order were carbon monoxide, other herbicides, and paraquat. Conclusion: This study showed the 2017-2018 status of poisoning in Korea. The prognosis is different from the cause of poisoning and the initial mental state of the patient. Therefore, appropriate methods for preventing poisoning and therapeutic plans in specific situations are needed.

The Relationship between Features of Foot Posture, Thickness of Intrinsic Foot Muscles and Dynamic Postural Stability

Gyucheol Shin,Taeyoung Kim,Woochan Chun,Sookyoung Park 한국운동생리학회 2023 운동과학 Vol.32 No.3

PURPOSE: This study aimed to determine the correlations between foot posture features, intrinsic foot muscles (IFMs) thickness, and dynamic postural stability. METHODS: Forty-one male participants were divided into two groups according to quantified foot postures using the Foot Posture Index (FPI-6) scores: the neutral foot group (FPI-6 score: 0 to +5) and the pronated foot group (FPI-6 score: >+6). The IFMs thickness was measured using ultrasound images of the flexor digitorum brevis (FDB), flexor hallucis brevis (FHB), and abductor hallucis muscles. To investigate the association between IFMs thickness and dynamic postural stability, the Biodex Balance System (BBS) was used in a single-leg stance position with both the eyes open and closed. RESULTS: In the BBS tests, the pronated foot group demonstrated significant results in the eyes-closed condition (p<.05). In particular, the differences between the eyes open and closed conditions in postural stability indices were significantly greater in the pronated foot group than in the neutral foot group (p<.05). No significant differences in IFMs thickness between the two groups were observed; however, some subdomains of the FPI-6 demonstrated significant positive correlations with postural stability indices and significant negative correlations with IFMs thickness (p<.05). The talonavicular joint was associated with FDB thickness (R=-0.311). Moreover, the forefoot was correlated with FHB thickness (R=-0.327). CONCLUSIONS: The aforementioned results suggest that dynamic postural stability and IFMs thickness are affected by the foot type. Although no significant differences in IFMs thickness were observed, dynamic postural stability and IFMs thickness reduced as the foot displayed features of pronation. This indicates that postural control ability and IFMs are vulnerable to changes in foot posture