Se-Yeon Park

Scapulothoracic Muscle Activity during Use of a Wall Slide Device (WSD), a Comparison with the General Wall Push up Plus.

[Purpose] The purpose of this study was to evaluate the effect of the wall slide device on activation of the scapulothoracic musculature. [Subjects] We recruited 15 healthy male subjects. [Methods] The subjects performed the general wall push-up plus (WPUP) and the wall slide with device (WSD) exercises. During the exercises, the muscle activities of the upper and lower trapezius (UT, LT), middle and lower serratus anterior (MSA, LSA), and pectoralis major (PM) were measured. [Results] The normalized muscle activity data of the WSD were significantly higher in UT, MSA and LSA than the WPUP. [Conclusion] Our results suggest that exercise using the WSD can more effectively activate the scapulothoracic musculature than the general WPUP.

Effects of the Sustained Computer Work on Upper Cervical Flexion Motion

[Purpose] The purpose of this study was to evaluate the effect of sustained computer work on cervical flexion, especially the upper cervical region. [Subjects] We recruited 11 sedentary workers who used a computer for at least 4 hours a day. [Methods] Total range of cervical flexion, upper cervical flexion, and their ratio were measured before and after 1 hour of computer work. [Results] The total range of cervical flexion was not significantly different between pre-and post-measurement. However, upper cervical flexion, and the ratio between the upper cervical flexion and total cervical flexion significantly decreased after 1 hour of computer work, compared to pre-measurement. [Conclusion] Sustained computer work affects the range of cervical flexion, especially in the upper cervical region.

Effect of Wearing a Tight Waist Belt on the Sagittal Kinematics of the Pelvis during Sit-to-Stand.

[Purpose] The purpose of the present study was to evaluate the effect of a tight waist belt on the human musculoskeletal system by assessing sagittal pelvic kinematic data during the sit-to-stand (STS) maneuver. [Subjects] Twelve asymptomatic males were recruited and three belt conditions were used during the STS. Sagittal kinematic data of pelvic motion were collected using a 3D motion-capture device [Results] The changes of the anterior pelvic tilt during the STS were significantly greater in the tight waist-belt condition than in the no-belt condition. [Conclusion] The results of this study show that wearing a tight waist belt increases anterior pelvic motion.

Comparison of isometric exercises for activating latissimus dorsi against the upper body weight.

Because there is little agreement as to which exercise is the most effective for activating the latissimus dorsi, and its intramuscular components are rarely compared, we investigated the intramuscular components of the latissimus dorsi during both trunk and shoulder exercises. Sixteen male subjects performed four isometric exercises: inverted row, body lifting, trunk extension, and trunk lateral bending. Surface electromyography (sEMG) was used to collect data from the medial and lateral components of the latissimus dorsi, lower trapezius, and the erector spinae at the 12th thoracic level during the isometric exercises. Two-way repeated analysis of variance with two within-subject factors (muscles and exercise conditions) was used to determine the significance of differences between the muscles and differences between exercise variations. The inverted row showed the highest values for the medial latissimus dorsi, which were significantly higher than those of the body lifting or trunk extension exercises. For the lateral latissimus dorsi, lateral bending showed significantly higher muscle activity than the inverted row or trunk extension. During body lifting, the % maximum voluntary isometric contraction (MVIC) of the erector spinae showed the lowest value, significantly lower than those of the other isometric exercises. The inverted row exercise was effective for activating the medial latissimus dorsi versus the shoulder depression and trunk exertion exercises. The lateral bending and body lifting exercises were favorable for activating the lateral component of the latissimus dorsi. Evaluating trunk lateral bending is essential for examining the function of the latissimus dorsi.

Potential for foot dysfunction and plantar fasciitis according to the shape of the foot arch in young adults

This study investigated potential for foot dysfunction and plantar fasciitis according to the shape of the foot arch in young adults. Fifty-two participants were required for the present study design to achieve 80% power, 0.8 effect size (η2), and an alpha level of 0.05. This study recruited 52 young adults (30 men and 22 women). All participants voluntarily agreed to participate in the study after hearing explanations about the purpose and process of the study. They were divided into two groups of 26 according to the shape of foot with and without flat foot using the navicular drop test. The participants were measured the foot function index (FFI), range of motion (ROM) of ankle, and four-way ankle strength. Additionally, the thickness of the plantar fascia was measured using ultrasonography. Intraclass correlation coefficient (ICC) was used to verify the inter- and intrarater reliability of ultrasonography. The inter- and intrarater reliability was excellent (ICC2,1=0.88, ICC3,1=0.93). There were significant differences in dorsi-flexion of ankle ROM, FFI, dorsi-flexion and eversion of ankle strength, and the thickness of the plantar fascia between the two groups (P<0.05). Based on the results, the group with flat foot may gradually generate potential of the foot dysfunction and plantar fasciitis. Therefore, the interventions are necessary to improve the foot dysfunction and plantar fasciitis in people with flat foot.

Changes of gait pattern, muscle activity, and perceived comfort in response to variations of height-elevating insoles in young adults

The purpose of this study was to investigate changes of gait pattern, muscle activity, and perceived comfort in response to variations of height-elevating insoles (HEIs) in young adults. The subjects of this study were 30 young adults who voluntarily consented to participate in this experiment after listening to its purpose and method. They were divided into 3 groups who wore HEIs height (0, 3, and 7 cm). Each group consisted of 10 young adults and wore the HEIs for 4 hr a day. Electromyographic signals were collected from the tibialis anterior, the gastrocnemius, the hamstring, and the right and the left erector spinae (ES) before and after walking with the HEI. Gait pattern was measured before and after walking with the HEI. Perceived comfort was measured after a subject wore the insoles for 4 hr. The activities of ES showed significant differences among the three groups. The activity of the left ES was significantly different between groups 1 (0 cm) and 2 (3 cm) and groups 1 and 3 (7 cm). The activity of the right ES was significantly different between groups 1 and 3. The left stride length and the left step length showed significant differences between groups 1 and 3. Perceived comfort was significantly different among the three groups. As the HEIs increased, the activities of ES were gradually increased and the left step length and stride were decreased. Using of higher HEIs over 4 hr may be occurred excessive activities of the ES, abnormal gait patterns, and perceived discomfort.

Effect of hip position and breathing pattern on abdominal muscle activation during curl-up variations

Recent studies have indicated that applying different breathing pattern and changes of extremity positions could be a useful way of performing challenging exercises that include coactivation of the abdominal muscles. The aim of this study was to investigate the effects of changes of breathing pattern and hip position on abdominal muscle activity during curl-up exercises. Surface electromyography responses of the rectus abdominis (RA), internal oblique (IO), external oblique (EO) muscles and rectus femoris (RF), and Borg rating of perceived exertion (Borg RPE) score were investigated during the curl up exercises. A total of 20 healthy, physically active male volunteers completed two hip positions (45° and 90° hip flexion) and three breath types (slow expiration, maximal inspiration, and maximal expiration) for curl-up variations. The curl-up with 90° of hip flexion significantly increased the muscular activities of IO, EO, RF, and Borg RPE score (P<0.05). The curl-up with maximal expiration significantly elevated the IO and EO activity, compared to other breathing conditions. There were no significant difference in RA activities (P>0.05). The present study showed both the hip position and breathing pattern affect abdominal muscle activities during the curl-up exercise, especially of the oblique muscles. Among the breathing patterns investigated herein, the curl-up with maximum expiration produced greater activation of the oblique muscles compared to slow expiration and maximum inspiration.

Comparison of muscular activities between subjects with and without scapular downward rotation impairment during diagonal pattern of exercises

BACKGROUNDSnOne form of abnormal scapular alignment is scapular downward rotation (SDR). Changes in muscle function in SDR have not been clearly identified, and SDR exercises also require investigation. Although a diagonal pattern of exercise is commonly used as part of the exercise protocol, a direct comparison of shoulder and scapular diagonal exercises has not yet been conducted. The objectives of this study were to determine the altered activation of the scapular musculature in the SDR group and to investigate which diagonal pattern of exercise effectively activates the scapular musculature.nnnMETHODSnThirty-two participants (18 in the control group and 14 in the SDR group) volunteered to participate in this study. Electromyographic signals were collected from four muscles, the upper trapezius (UT), lower trapezius (LT), serratus anterior (SA), and anterior deltoid (AD), during standing performance of diagonal shoulder and scapular exercises.nnnRESULTSnThe control group showed significantly lower UT activity, UT/LT ratio, and UT/SA values than the SDR group (pu202f<u202f.05). Activation of the AD was significantly higher in the SDR than in the control group (pu202f<u202f.05). SA and AD activation were significantly higher in shoulder diagonal pattern exercises than in scapular diagonal pattern exercises (pu202f<u202f.05). The scapular posterior elevation pattern exercise showed significantly higher UT and LT activities than anterior elevation and shoulder diagonal pattern exercises (pu202f<u202f.05).nnnCONCLUSIONnOur findings suggest that reduced activation of the UT could lead to greater activation in the AD in SDR. Scapular posterior elevation exercise is advantageous as selectively activates the trapezius musculature, and shoulder diagonal pattern exercise is advantageous in activating the SA and AD.

The study of trunk and pelvic movement on mediolateral ramps of various ramp angles during one-legged standing

The purpose of this study was to identify the instability of the trunk and the pelvis of subjects who were standing on differently angled ramps under conditions in which the ramps were crossed. Changes in the trunk and the pelvis while each subject was standing on one leg in the direction of the cross ramps at four angles (0°, 5°, 10°, and 15°) were measured. To identify instability, the trunk inclination, trunk imbalance, pelvic position, pelvic rotation, and pelvic torsion of 20 healthy male subjects were measured. The measurement was conducted using a three-dimensional spinal diagnostic imaging system (Back Mapper). According to the results of the measurement, trunk imbalance, pelvic position, pelvic rotation, and pelvic torsion differed between the medial and lateral ramps and with different ramp angles. This study’s results suggested that different mediolateral ramp conditions altered the pelvic and trunk alignment. With the 15° ramp, the anterior tilt and lateral tilt of the pelvis increased regardless of ramp direction. The 10° ramp condition altered the pelvic rotation to the contralateral side. In addition, the lateral trunk tilt was elevated with the lateral down foot condition.

Immediate effects of the trunk stabilizing exercise on static balance parameters in double-leg and one-leg stances

[Purpose] The purpose of this study was to evaluate the immediate effect of stabilizing exercise using the PNF technique on standing balance in one-leg and double-leg stances. [Subjects and Methods] The present study recruited 34 healthy participants from a local university. The Participants performed four balance tests (double-leg stance with and without vision, one-leg stance with and without vision), before and after exercise. The exercise consisted of exercises performed using PNF techniques (stabilizing reversal and rhythmic stabilization), which were applied to facilitate trunk musculature. To examine balance ability, total displacement of the center of pressure was measured during balance tests. [Results] The total anterior–posterior center of pressure displacement was significantly reduced after applying rhythmic stabilization compared before exercise regardless of the balance test conditions. [Conclusion] The present results suggest that trunk stability exercise using rhythmic stabilization could effectively enhance balance ability under one-leg and double-leg conditions.