• Journal of the Korean Society of Physical Medicine
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• v.16 no.1
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• pp.111-121
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• 2021

PURPOSE: This study examined the effects of core stability exercise on the strength, activation of the trunk muscle, and pulmonary function in a Guillain-Barre syndrome (GBS) patient. METHODS: A 38-year-old male with GBS was enrolled in the study. A core stability exercise program was implemented for four weeks with a duration of 30 min/day and a frequency of three days/week. The program consisted of abdominal crunch, Swiss ball crunch, bicycle crunch, medicine ball sit-up with a toss, medicine ball rotational chest pass, raised upper body and lower body, and dead bug. Measurements of the strength of the trunk muscle (trunk flexion and hip flexion), activation of trunk muscles (rectus femoris; RA, external oblique abdominal; EOA, internal oblique abdominal; IOA, erector spinae; ES), and pulmonary function (forced expiratory capacity; FVC, forced expiratory volume at one second; FEV1) were taken before and after four weeks of core stability exercise. RESULTS: The strength of trunk muscles increased in the trunk and hip flexion after four weeks of core stability exercise, respectively, compared to the baseline levels. Activation of the trunk muscles increased in RA, EOA, and IOA after four weeks of core stability exercise compared to baseline levels, but decreased in ES after four weeks of core stability exercise compared to the baseline levels. The pulmonary function increased in FVC and FEV1 after four weeks of core stability exercise compared to the baseline levels. CONCLUSION: These results suggest that core stability exercise improves strength, Activation of the trunk muscle, And pulmonary function in patients with GBS.

• PNF and Movement
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• v.20 no.1
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• pp.91-101
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• 2022

Purpose: The purpose of this study was to examine the effect of cycle ergometer exercise inducing movement of the affected side on knee joint function after total knee arthroplasty (TKA). Methods: The primary experiment was conducted on 19 members of the cycle ergometer exercise group to measure the muscle activity of the rectus femoris, hamstring, tibialis anterior, and gastrocnemius muscles during cycle ergometer exercise that induced the affected side's movement. In the second experiment, after receiving physiotherapeutic intervention for 30 min, the general bicycle exercise group and cycle ergometer exercise group performed the corresponding exercise for 15 min, 5 times per week, for 2 weeks. The ROM, muscle strength, pain, and balance were then measured and compared between the two groups. Results: In the results of the primary experiment, cycle ergometer exercise inducing movement of the affected side showed a significantly larger increase in the activity of leg muscles (rectusfemoris, hamstring, tibialis anterior, gastrocnemius) on the affected side than the general bicycle exercise (p <0.05). In the second experiment, the cycle ergometer exercise group showed a significantly larger increase in range of movement of affected side knee flexion and muscle strength of affected side knee flexion, knee extension, and plantarflexion than the general bicycle exercise (p <0.05). No significant between-group difference was observed in pain and balance before or after the intervention (p >0.05). Conclusion: Cycle ergometer exercise inducing movement of the affected side increases use of the muscles around the affected side knee joint after TKA more than general bicycle exercise and produces better effects for enhancing muscle strength. The application of cycle ergometer exercise inducing movement of the affected side is expected to reduce the patients' unbalanced use during the early postoperative period and help them to quickly return to normal daily life through rapid muscle strength recovery.

• Korean Journal of Applied Biomechanics
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• v.32 no.2
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• pp.43-48
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• 2022

Objective: The purpose of this study was to verify the effectiveness among simulating ski jumping trainings by comparing with actual ski jump. Method: Three healthy youth national athletes were recruited for this study (age: 13.70 ± 0.9 yrs, height: 169.30 ± 0.9 cm, jumping caree: 5.3 ± 0.9 yrs). Participants were asked to performed ski jumping with 3 simulating and one actual situation. A 3-dimensional motion analysis with 5 channels of EMG was performed in this study. Muscle activations of Rectus Femoris [RF], Tibialis Anterior [TA], Thoracis [TH], Gluteus maximus [GM], and Gastronemius [GL] were achieved with sampling rate of 2,000 Hz during each jump. Results: In the case of S1 in the actual jumping motion, the deviation of the muscle activity peak did not appear each trial, and the jump timing was consistent. For S2, the timing of the muscles peak activation which can maintain the posture of the upper body and ankles appeared at the beginning. In the case of S3, the part maintaining the ankle posture at the beginning appeared, but it could be expected that it would progress in the vertical direction due to the activation of GL at the time of jumping. Conclusion: The muscle activation peak before the take-off point showed a different pattern for each athlete, and individual differences were large. In addition, it was attempted to confirm the actual jump with simulation jump, and it was found that not only the difference in patterns but also the fluctuations in the timing of each muscle activation peak were large.

• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.758-765
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• 2019

The purpose of the this study was to determine the comparative analysis of body muscle activities in plank exercise with and without thera-band. Twelve healthy adult males(age, $21.75{\pm}.57$ years; height, $173.33{\pm}1.34cm$; body mass, $65.92{\pm}1.64kg$; and BMI, $21.93{\pm}.46kg/m^2$) participated in this study as subjects. Plank exercises(full, elbow, side, and reverse plank) were performed with four different thera-band in without(WT), red color(RT), blue color(BT), and siver color(ST). We measured the muscle activities of the erector spinae(ES), deltoideus p. acromialis(DA), external oblique(EO), rectus abdominis(RA), rectus femoris(RF), latissimus dorsi(LD), pectoralis major(PM), and biceps femoris(BF). The research findings were as follows. ES and DA muscle activities were greatest during full plank performed with the WT(p<.05). EO, RA, RF, and PM muscle activities were greatest during full plank performed with the ST(p<.05). ES and DA muscle activities were greatest during elbow plank performed with the WT(p<.05). RF and PM muscle activities were greatest during elbow plank performed with the ST(p<.05). ES, EO, RA, RF, LD, PM, and BF muscle activities were greatest during side plank performed with the ST(p<.05). DA, EO, RA, RF, LD, PM, and BF muscle activities were greatest during reverse plank performed with the ST(p<.05). These results are expected to serve as reference materials for plank exercise applications in training programs for body muscle strengthening.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.137-148
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• 2006

The purpose of this study was to compare muscle activity in the lower extremity during walking wearing jogging and roller shoes. Twelve male middle school students (age: 15.0 yrs, height 173.7 cm, weight 587.7 N) who have no known musculoskeletal disorders were recruited as the subjects. Seven pairs of surface electrodes (QEMG8, Laxtha Korea, gain = 1,000, input impedance >$1012{\Omega}$, CMMR >100 dB) were attached to the right-hand side of the body to monitor the rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF), tibialis anterior (TA), and medial (GM) and lateral gastrocnemius (GL) while subjects walked wearing roller and jogging shoes in random order at a speed of 1.1 m/s. An event sync unit with a bright LED light was used to synchronize the video and EMG recordings. EMG data were filtered using a 10 Hz to 350 Hz Butterworth band-passdigital filter and further normalized to the respective maximum voluntary isometric contraction EMG levels. For each trial being analyzed, five critical instants and four phases were identified from the recording. Averaged IEMG and peak IEMG were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between shoe conditions (p<.05). The VM, TA, BF, and GM activities during the initial double limb stance and the initial single limb stance reduced significantly when going from jogging shoe to roller shoe condition. The decrease in EMG levels in those muscles indicated that the subjects locked the ankle and knee joints in an awkward fashion to compensate for the imbalance. Muscle activity in the GM for the roller shoe condition was significantly greater than the corresponding value for the jogging shoe condition during the terminal double limb stance and the terminal single limb stance. Because the subjects tried to keep their upper body weight in front of the hip to prevent falling backward, the GM activity for the roller shoe condition increased. It seems that there are differences in muscle activity between roller shoe and jogging shoe conditions. The differences in EMG pattern may be caused primarily by the altered position of ankle, knee, and center of mass throughout the walking cycle. Future studies should examine joint kinematics during walking with roller shoes.

• Korean Journal of Applied Biomechanics
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• v.25 no.3
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• pp.323-333
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• 2015

Objective : The purpose of this study was to investigate the changes of gait patterns and muscle activations with increased loads during stair walking. Also, it can be used as descriptive data about continuous stair walking in a real life setting. Method : Twelve sedentary young male adults(Age: $27.0{\pm}1.8yrs$, Weight: $65.8{\pm}9.9kg$) without any lower extremity injuries participated in this study. Participants performed stair walking up 7 floors and their ascending and descending motion on each floor was analyzed. A wireless electromyography(EMG) were attached on the Rectus Femoris(RF), Biceps Femoris(BF), Gastrocnemius(GN), Tibialis Anterior(TA) muscle to calculate integrated EMG(iEMG), median frequency(MDF) and co-contraction index(CI). Chest and left heel accelerometer signal were recorded by wireless accelerometer and those were used to calculate approximate entropy(ApEn) for analyzing gait pattern. All analyses were performed with SPSS 21.0 and for repeated measured ANOVA and Post-hoc was LSD. Results : During ascending stairs, there were a statistically significant difference in Walking time between 1-2nd and other floors(p=.000), GN iEMG between 2-3th and 6-7th(p=.043) floor, TA MDF between 1-2nd and 5-6th(p=.030), 6-7th(p=.015) floor and TA/GN CI between 2-3th and 6-7th(p=.038) floor and ApEn between 1-2nd and 6-7th(x: p=.003, y: p=.005, z: p=.006) floor. During descending stairs, there were a statistically significant difference in TA iEMG between the 6-5th and 3-2nd(p=.026) floor, and for the ApEn between the 1-2nd and 6-7th(x: p=.037, y: p=.000, z: p=.000) floor. Conclusion : Subjects showed more regular pattern and muscle activation response caused by regularity during ascending stairs. Regularity during the first part of stair-descending could be a sign of adaptation; however, complexity during the second part could be a strategy to decrease the impact.

• Korean Journal of Applied Biomechanics
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• v.21 no.2
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• pp.215-222
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• 2011

The purpose of this study was to analyze the effects of the use of the lower extremity supporter to ground reaction force(GRF) & EMG in women. Five women participated in the experiment conducted in the study(age: $46.7{\pm}3.5$ yrs, weight: $52.3{\pm}2.2$ kg, lower extremity height: $74.1{\pm}0.9$ cm, knee height: $40.7{\pm}1.4$ cm). The Ground reaction force was measured by AMTI ORG-6 and the Muscle activity of the lower extremity was measured by an 8-channel surface EMG system(Noraxon Myoresearch, USA, 1000Hz). We statistically compared muscle activity and ground reaction force with and without the lower-extremity supporter by one-way repeated ANOVA. The results were as follows. First, the use of the lower extremity supporter affects the ground reaction force along the anterior-posterior axis(Y). Second, the vertical(Z-axis) reaction force on the upper part of the lower extremity supporter increase because of the difference between the interval of vertical movement. Third, the muscle activity of the lateral gastrocnemius and rectus femoris was higher in the upper part of the lower extremity supporter. Further research for example, on a comparative analysis of joint moments, the effects of direct stressor on joints. and the relationship between muscle activity and joint movement, is necessary for a better understanding of the effects of the lower-extremity supporter.

• Korean Journal of Applied Biomechanics
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• v.29 no.2
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• pp.105-112
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• 2019

Objective: The main purpose of this study was to investigate the effects of wearing an ankle weight belt while performing gait in water by focusing on the effect of using ankle weights have on the gait kinematics and the muscle activities for developing optimum training strategies. Method: A total of 10 healthy male university students were recruited for the study. Each participant was instructed to perform 3 gait conditions; normal walking over ground, walking in water chest height, and walking in water chest height while using ankle weights. All walking conditions were set at control speed of $4km/h{\pm}0.05km/h$. The depth of the swimming pool was at 1.3 m, approximately chest height. The motion capture data was recorded using 6 digital cameras and the EMG was recorded using waterproof Mini Wave. From the motion capture data, the following variables were calculated for analysis; double and single support phase (s), swing phase (s), step length (%height), step rate (m/s), ankle, knee, and hip joint angles ($^{\circ}$). From the electromyography the %RVC of the lower limb muscles medial gastrocnemius, rectus femoris, erector spinae, semitendinosus, tibialis anterior, vastus lateralis oblique was calculated. Results: The results show significant differences between the gait time, and step length between the right and left leg. Additionally, the joint angular velocities and gait velocity were significantly affected by the water resistance. As expected, the use of the ankle weights increased all of the lower leg maximum muscle activities except for the lower back muscle. Conclusion: In conclusion, the ankle weights can be shown to stimulate more muscle activity during walking in chest height water and therefore, may be useful for rehabilitation purposes.

• Physical Therapy Korea
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• v.26 no.2
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• pp.16-23
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• 2019

Background: High-heeled shoes can change spinal alignment and feet movement, which leads to muscle fatigue and discomfort in lumbopelvic region, legs, and feet while walking. Objects: This study aimed to identify the effects of different shoe heel heights on the walking velocity and electromyographic (EMG) activities of the lower leg muscles during short- and long-distance walking in young females. Methods: Fifteen young females were recruited in this study. The experiments were performed with the following two different shoe heel heights: 0 cm and 7 cm. All participants underwent an electromyographic procedure to measure the activities and fatigue levels of the tibialis anterior (TA), medial gastrocnemius (MG), rectus femoris (RF), and hamstring muscles with each heel height during both short- and long-distance walking. The walking velocities were measured using the short-distance (10-m walk) and long-distance (6-min walk) walking tests. Results: Significant interaction effects were found between heel height and walking distance conditions for the EMG activities and fatigue levels of TA and MG muscles, and walking velocity (p<.05). The walking velocity and activities of the TA, MG, and RF muscles appeared to be significantly different between the 0 cm and 7 cm heel heights during both short- and long-distance walking (p<.05). Significant difference in the fatigue level of the MG muscle were found between the 0 cm and 7 cm heel heights during long-distance walking. In addition, walking velocity and the fatigue level of the MG muscle at the 7 cm heel height revealed significant differences in the comparison of short- and long-distance walking (p<.05). Conclusion: These findings indicate that higher shoe heel height leads to a decrease in the walking velocity and an increase in the activity and fatigue level of the lower leg muscles, particularly during long-distance walking.

• Korean Journal of Applied Biomechanics
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• v.31 no.3
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• pp.189-198
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• 2021

Objective: The aim of this study is to investigate the effect of biomechanical variables on gait according to indoor and outdoor environmental conditions in elderly women at risk of falling. Method: 26 elderly women aged 70 years or older, and consisted of 13 elderly people with a walking speed of less 1.0 m/s and 13 people in the fall risk group as normal groups. Depending on the purpose of the study, physical examination and psychological questionnaire were prepared, and then walking was performed in an indoor/outdoor environment, and the gait pattern, muscle activity, and plantar pressure results were compared and analyzed in the elderly females through a 2 group × 2 environment 2-way repeted ANOVA analysis. Results: The gait variable showed an interaction effect the cadence. The muscle variables showed interaction effects in the rectus femoris and tibialis anterior muscles, and the interaction effects of the plantar pressure variables were confirmed in the forefoot and midfoot of the contact area, and the midfoot of the mean pressure. Conclusion: These results indicate that both groups are exposed to falls risk when gait in an outdoor environment, but the fall risk group has a higher risk of falls in both the gait pattern, muscle activity, and plantar pressure variables. The results of this study are considered to be helpful as basic data and development of exercise programs to prevent falls.