Oh-Yun Kwon

• PhD
• Professor at Yonsei University

Background Ankle injuries in parcel delivery workers (PDWs) are most often caused by trips. Ankle sprains have high recurrence rates and are associated with chronic ankle instability (CAI). This study aimed to develop, determine, and compare the predictive performance of statistical machine learning models to classify PDWs with and without CAI usin...

Background Although lumbopelvic rotation control muscle is important to maintain pelvic neutral alignment during active straight leg raise (ASLR), pelvic rotator strength has not been evaluated. Thus, a novel method is needed to measure pelvic rotator strength and to determine whether pelvic rotator muscle asymmetry is related to side difference in...

Context: Active management of modifiable factors during the early rehabilitation stage can help patients who have undergone anterior cruciate ligament (ACL) reconstruction successfully return to sports. This study aimed to determine predictors for performance on the single-leg hop test and Tegner activity score 12-month post-ACL reconstruction, ba...

This study aimed to evaluate the effectiveness of our newly developed virtual reality head-mounted display (VR-HMD) "walker avoidance" game in reducing step-aside reaction time (SART) and enhancing agility in collision avoidance. 15 young adults in experimental group (EG) engaged in the “walker avoidance” game, while another 15 young adults in the...

Background: Lateral epicondylitis (LE), also called tennis elbow, is a common musculoskeletal disorder that causes pain in the elbow area and is highly prevalent in assembly workers who repeatedly move their wrists. Objective: The purpose of this study was to compare the wrist ROM and muscle strength of assembly workers with and without LE. Met...

Objectives The traditional understanding of craniocervical alignment emphasizes specific anatomical landmarks. However, recent research has challenged the reliance on forward head posture as the primary diagnostic criterion for neck pain. An advanced relationship exists between neck pain and craniocervical alignment, which requires a deeper explora...

The craniocervical flexion test (CCFT) is commonly used for assessing the performance and function of the deep cervical flexor muscles; however, objective measurements of cervical segmental motion during craniocervical flexion (CCF) are lacking. Therefore, the purpose of this study aimed to investigate cervical segmental motions during CCFT and det...

Abstract Objective: Physical therapists and clinicians commonly confirm craniocervical posture (CCP), cervical retraction, and craniocervical flexion as screening tests because they contribute to non-specific neck pain (NSNP). We compared the predictive performance of statistical machine learning (ML) models for classifying individuals with and wit...

Objective Ankle injuries in delivery workers (DWs) are often caused by trips, and high recurrence rates of ankle sprains are related to chronic ankle instability (CAI). Heel rise requires joint angles and moments similar to those of the terminal stance phase of walking that the foot supinates. Thus, our study aimed to develop, determine, and compar...

Subacromial pain syndrome (SAPS) is the most common upper-extremity musculoskeletal problem among workers. In this study, a machine learning model was built to predict and classify the presence or absence of SAPS in assembly workers with shoulder joint range of motion (ROM) and muscle strength data using support vector machine (SVM). Permutation im...

Background: Maintaining correct posture and optimal spine function has become an important issue due to the increased use of computers and smartphones. Objective: To investigate the effect of a 4-week downhill treadmill exercise (DTWE) program on participants with thoracic kyphosis and forward head posture (FHP). Methods: Twenty-eight male par...

Pulmonary complications are frequent in stroke, contributing to both mortality and morbidity rates. Respiratory parameters in such patients encompass both pulmonary function and respiratory muscle strength. Identifying respiratory function variables that influence the balance and gait ability of patients with stroke is crucial for enhancing their r...

Background: The restoration and management of the uninvolved side have been emphasized to prevent a second anterior cruciate ligament (ACL) injury and to ensure that athletes return to sports after ACL reconstruction. Objective: To determine the factors influencing the single leg hop test (SLHT) and single leg vertical jump test (SLVJT) at 1 yea...

Background: Electrical muscle stimulation (EMS) has been applied in many rehabilitation settings for muscle strengthening, facilitation of muscle contraction, re-education of muscle action, and maintenance of muscle strength and size during prolonged immobilization. Objective: The purpose of this study was to investigate effect of 8 weeks of EMS...

Background Upper trapezius (UT) pain with myofascial trigger points (MTrPs) can affect movement at the glenohumeral joint as well as at the scapulothoracic joint. The investigation of muscle recruitment patterns can discern motor control strategies. The purpose of this study was to compare shoulder muscle recruitment patterns and muscle activity ac...

Background: The occurrence of subacromial pain syndrome (SPS) is associated with the frequent handling and lifting of heavy loads and excessive repetitive work. Thus, assembly workers have a high prevalence of SPS. Objective: The purpose of this study was to investigate differences in shoulder ROM, muscle strength, asymmetry ratio, function, pro...

Introduction: Stroke patients have problems with voluntary movement and trunk control. Moreover, the respiratory function in stroke patients is affected by neurological impairment, which increases the incidence of respiratory complications. Objectives: To determine the correlation between trunk rotation range of motion (TRROM) and trunk lateral...

It is unclear which factors contribute to the developing pressure pain hypersensitivity of the upper trapezius, a type of neurophysiological hyperexcitability. The present study investigated the relationship between physical and psychological factors and pressure pain hypersensitivity of the upper trapezius for each sex. In total, 154 individuals w...

Various vaccines for the infectious Coronavirus Disease of 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) have already been developed and used, but breakthrough infections continue to occur despite the administration of additional booster injections. Various therapeutic agents are being developed during the p...

Background: Thoracic hyperkyphosis structurally alters the position of the scapula to cause forward shoulder posture. However, the effect of improved thoracic hyperkyphosis on forward shoulder posture is unclear. The objective of this study was to determine the effect of eight weeks of thoracic mobilization on improving thoracic hyperkyphosis and...

Background Upper trapezius (UT) pain with myofascial trigger points (MTrPs) can affect movement at the glenohumeral joint as well as at the scapulothoracic joint. The investigation of muscle recruitment patterns can discern motor control strategies. The purpose of this study was to compare shoulder muscle recruitment patterns and muscle activity ac...

Introduction: The pelvic floor muscle (PFM) plays a role not only in lumbopelvic stabilization, but also in incontinence and sexual function. Objective: This study aimed to determine the effectiveness of PFM training by electrical stimulation (ES) on urinary incontinence, PFM performance (i.e. strength and power), lumbopelvic control, and abdomi...

Research Objectives The objective of the present study was to investigate the impact of physical activity on the quality of life (QOL) of Korean middle-aged women with urinary incontinence (UI) by using the online questionnaire constructed for this study. Design This is an online survey study. An online survey was conducted between August 2020 and...

Background: The Y-Balance test (YBT) is commonly used to evaluate balance after anterior cruciate ligament reconstruction (ACLR). However, several studies have also used it as a functional performance test (FPT). Purpose: This study aimed to examine the relationship between YBT scores and measures of knee joint laxity, static balance, knee flexo...

Kim, J-H, Kwon, O-Y, Hwang, U-J, Jung, S-H, Ahn, S-H, and Kim, H-A. Comparison of shoulder external rotator strength and the asymmetry ratio between workers with and without shoulder impingement syndrome. J Strength Cond Res XX(X): 000-000, 2019-Shoulder impingement syndrome (SIS) is the most common shoulder problem causing shoulder pain. Several s...

Background During the empty can test, the direction of the thumb (downward) has been widely used as an instruction for producing glenohumeral internal rotation. However, the combination of forearm pronation and thumb motion as a compensatory movement could contribute to the lack of glenohumeral internal rotation during the empty can test. This stud...

Background: Thoracic mobilisation improves thoracic hyperkyphosis and respiratory function. Diaphragmatic excursion is associated with respiratory function; however, limited studies have assessed the effect of thoracic mobilisation on diaphragmatic excursion. Objective: This study aimed to investigate the effects of thoracic mobilisation on diap...

BACKGROUND: The focus of exercises for restoring the imbalance between scapular upward rotator muscles – upper trapezius (UT), serratus anterior (SA), and lower trapezius (LT) – commonly aims to increase SA and LT activities while not increasing UT activity. OBJECTIVES: The purpose of this study was to compare the activity of the UT, SA, and LT mus...

BACKGROUND: The aim of this study is to investigate the location of nerves that innervate the flexor digitorum profundus (FDP), the flexor pollicis longus (FPL) and the pronator quadratus muscles. It also investigates the change in nerve location with hand movement. MATERIALS AND METHODS: We studied 30 adult cadavers (17 males and 13 females) with...

Background: Due to the extended use of smartphones, people spend a lot of time on these devices while lying down. Objective: The purpose of the present study was to compare the differences in neck muscle activity of participants while they watched videos on a smartphone in four different lying positions (supine (SUP), prone on elbows (PE), side...

Introduction: The pelvic floor muscle (PFM) could affect female sexual functions. The hip muscles are morphologically and functionally linked to PFM and are important elements of female sexual attraction. Aim: To determine the relationship between female sexual function and hip muscle strength and PFM functions in women with stress urinary incon...

Background Faults in postural alignment and movement of the pelvis are associated with non-specific low back pain. However, limited studies have investigated the differences in pelvic rotation angle in the transverse plane in the supine position and during active straight leg raise between subjects with and without non-specific low back pain. Meth...

Objectives: It is unclear which factors increase the risk of developing pressure pain hypersensitivity, a type of neurophysiological hyperexcitability. The present study investigated the relative contributions of physical and psychological factors to pressure pain hypersensitivity of the upper trapezius for each sex. Methods: In total, 154 individu...

Background: The pelvic floor muscle (PFM) is associated with respiratory function. We investigated the effects of PFM training by pelvic floor electrical stimulation (PFES) on PFM strength, diaphragm excursion, and upper rib cage movement during tidal and forceful breathing and coughing in women with stress urinary incontinence (SUI). Methods: In...

Background: This study was performed to determine the effectiveness of 8 weeks of pelvic floor muscle (PFM) training by electrical stimulation (ES) on PFM function, lumbopelvic control, abdominal muscle thickness, and the contraction ratio in women with stress urinary incontinence (SUI). Methods: Women with SUI were randomized into an ES group (n =...

Background The aim of this study was to demonstrate the effect of surface electrical stimulation in a seated position (SESSP), as pelvic floor muscle (PFM) training, on PFM functions (time to reach maximal pressure [TRMP], muscle strength, power and endurance), urinary leakage and quality of life in patients with stress urinary incontinence (SUI)....

Background: Manual therapy has been recommended to reduce and prevent musculoskeletal problems related to thoracic hyperkyphosis. With recent rapid technological developments, manual techniques can now be implemented by mechanical devices; hence, mechanical massage can manipulate the back muscles and mobilize the spine. Purpose: Here, we aimed t...

Background: Stress urinary incontinence is an involuntary leakage of urine due to a weak pelvic floor and weak sphincter when the intra-abdominal pressure increases. Its symptoms are known to improve upon electrical stimulation of the pelvic floor. This study aimed to determine the effects of transcutaneous electrical stimulation on ultrasonography...

Objective Dysfunction of the pelvic floor muscles (PFM) is associated with sexual dysfunction in women with stress urinaryincontinence (SUI). The EasyK7 device was developed to stimulate the PFM by surface electrical stimulation duringsitting (SESdS). We investigated the effects of SESdS on PFM function and sexual function in women with SUI.Methods...

The occurrence of shoulder impingement syndrome (SIS) is associated with the frequent handling and lifting of heavy loads and excessive repetitive work above the shoulder level. Thus, assembly workers have a high prevalence of shoulder injuries, including SIS. The purpose of this study was to investigate differences in shoulder ROM, muscle strength...

Purpose: To compare the effectiveness of blocked and random practice schedules of balance training in dynamic balance abilities of older adults using Wii Fit balance game tasks. Method: Forty-one participants who were not receiving hospice care or living in a nursing home participated. Three Wii Fit balance tasks (tasks A, B, and C) were selected f...

Background: Increased genu recurvatum (GR) angle is a risk factor for knee injury. Identification of factors causing GR is important for the prevention and rehabilitation of GR. Few studies have investigated the association between muscle strength and GR. Objective: To examine the association between GR angle and hip and knee muscle strength in...

Although lumbopelvic stability exercise improves lumbopelvic motor control function in patients with chronic low back pain (CLBP), the difference in lumbopelvic motor control function between the patients with CLBP and the healthy controls is unclear. The purpose of this study was to compare lumbopelvic motor control function between patients with...

Objective Low back pain (LBP) has commonly been managed via classification-specific interventions in homogeneous groups. However, it is largely unknown whether treatment tailored to specific classifications is more effective than generic treatment. The purpose of this study was to evaluate the effects of classification-specific treatment on the sel...

Background: Neuromuscular electrical stimulation (NMES) devices for abdominal muscles are being marketed to the general public to improve physical appearance. Abdominal muscles play an important role in lumbopelvic stability for optimizing performance. We investigated the effects of NMES training of abdominal muscles on muscle size, muscle strengt...

Objective Stress urinary incontinence (SUI) is defined as involuntary urine loss during effort, sneezing, or coughing. We investigated which pelvic floor muscle (PFM) functions (muscle strength, power, and endurance) are associated with improvement in subjective and objective symptoms after 8 weeks of surface electrical stimulation (SES) training....

Background Weakness of evertor strength is controversial in chronic ankle instability (CAI). Ankle evertor muscles are attached to the toe joints as well as to the metatarsal bone. Therefore, it is necessary to consider toe joint position for the measurement of evertor strength. The purpose of this study was to compare ankle evertor strength and mu...

Context: Electrical muscle stimulation (EMS) was designed for artificial muscle activation or superimposed training. Objectives: To compare the effects of 8 weeks of superimposed technique (ST; application of electrical stimulation during a voluntary muscle action) and EMS on the cross-sectional area of the rectus abdominis, lateral abdominal wa...

Context: Side bridge exercises strengthen the hip, trunk, and abdominal muscles and challenge the trunk muscles without the high lumbar compression associated with trunk extension or curls. Previous research using electromyography (EMG) reports that performance of the side bridge exercise highly activates the gluteus medius (Gmed). However, to the...

Background The aim of this study was to demonstrate the effect of surface electrical stimulation in a seated position (SESSP), as pelvic floor muscle (PFM) training, on PFM functions (time to reach maximal pressure [TRMP], muscle strength, power and endurance), urinary leakage and quality of life in patients with stress urinary incontinence (SUI)....

Background: Previous studies suggested that patients with symptomatic intervertebral disc degeneration (IDD) of lumbar spine have reduced cross-sectional area (CSA) and functions of core muscles. However, reduced CSA and functions of core muscles have been observed not only in patients with symptomatic IDD but also in patients with other subgroups...

Background: Ankle evertor muscles are important for preventing lateral ankle sprain. Since, the evertor muscles cross the ankle and toe joints, the position at which the ankle evertor muscle strength is measured is important. However, no studies have previously investigated the effect of ankle and toe positions on the strength of the ankle evertor...

Introduction Stress urinary incontinence (SUI) is often associated with female sexual dysfunction. We investigated which pelvic floor muscle (PFM) parameters (strength, power, and endurance) are associated with improvement of sexual function after 8 weeks of transcutaneous electrical stimulation (TES) training. Aim This study was performed to dete...