• PNF and Movement
• /
• v.17 no.1
• /
• pp.137-144
• /
• 2019

Purpose: This study examined the effects of the abdominal drawing-in maneuver (ADIM) on muscle activity in the trunk and legs while subjects walk on a ramp. Methods: The subjects were healthy adult males (n=15) and females (n=8) in their twenties. The subjects were asked to maintain the ADIM contraction for 15 minutes using a pressure biofeedback unit. Their muscle activity was then measured while ascending or descending the ramp with or without the ADIM contraction maintained. Activity in the sternocleidomastoid, splenius capitis, rectus abdominis, external oblique abdominal, transversus abdominis, erector spinae, vastus medialis, and vastus lateralis muscles was measured using surface electromyography (TM DTS, Noraxon, USA). A paired t-test was conducted using SPSS 18.0 (IBM) for statistical data processing. Results: Maintaining the ADIM contraction during ascension led to a significant increase (p<0.05) in muscle activity for the rectus abdominis, transversus abdominis, vastus medialis, and vastus lateralis, but a significant decrease (p<0.05) in muscle activity for the erector spinae, when compared to the same activity without the ADIM maintained. Furthermore, maintaining the ADIM contraction during descent led to a significant increase (p<0.05) in muscle activity for the rectus abdominis, external abdominal oblique, transversus abdominis, vastus medialis, and vastus lateralis, but a significant decrease (p<0.05) in muscle activity for the erector spinae, when compared to the same activity without the ADIM maintained. Conclusion: As a result of this study, it maintains the ADIM and reduces lumbar muscle activity at the waist and increases muscle activity in the legs when walking on a ramp. Therefore, maintaining the ADIM contraction during ramp walking is recommended as training to improve the function of patients' muscular skeleton.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.15 no.6
• /
• pp.1967-1974
• /
• 1991

When the functional electrical stimulation is employed to recover mobility to the plegic, it is very important to understand functions of the selected muscles. I have investigated how a muscle acts to accelerate the body segments, since the body segements are connected by joints so that contraction of a muscle not only rotates the segments to which it is attached but also causes other segments to rotate by creation a reaction force at every joint, which is called the inertial coupling. I found that a single-joint muscle always acts to accelerate the spanned joint in the same direction as the joint torque produced by the muscle. However, a double-joint muscle can act to accelerate the spanned joint in the opposite direction to the joint torque produced by the muscle depending on (1) the body position, (2) the body-segmental parameters, and (3) the type of the movement. Investigating the condition number of the inertia matrix of the body-segmental model gave us some insights into how controllable the body-segmental system is for different values of the factors mentioned above. The results suggested that the upright position is the most undesirable position to independently control the three segments(trunk, thigh and shank) and that the controllability is the most sensitive to variation of the shank length and the trunk mass, which implies that accuracy is required particularly when we estimate these two body-segmental parameters before the paralyzed muscles are innervated by using electrical stimulation.

• Physical Therapy Rehabilitation Science
• /
• v.6 no.1
• /
• pp.33-38
• /
• 2017

Objective: This study tried to examine the muscle activity of the neck and trunk according to head posture changes during use of laptops. Design: Cross-sectional study. Methods: This study included nineteen young men and women. All subjects maintained each posture while practice typing on laptops for ten minutes with a 5-minute break between each posture. For the neutral head posture, the subjects practiced typing while pulling their chins down towards the Adam's apple and were able to look at their knees while having their external auditory meatus, acromion, and greater trochanter vertical to the ground. For the natural head posture, they practiced typing while balancing their posture between extension and flexion of the cervical vertebrae by themselves without any guidelines. While a forward head posture was created by having their heads face the front horizontal to the rope hanging from the ceiling, they practiced typing with their external auditory meatus located in the place which was 5 cm in front of the vertical plane. The subjects used general word process but practiced typing with accuracy and high speed. Muscle activities were randomly measured using surface electromyography according to each postures. Results: The research result had found that muscle activity with the natural head posture was more significantly reduced than that of the forward head posture in the sternocleidomastoid muscle, upper trapezius, cervical vertebral spinae, and thoracic vertebrae spinae muscles (p<0.05) and that the neutral head posture was more significantly reduced than that of forward head posture in the upper trapezius, cervical vertebral spinae, and thoracic vertebrae spinae muscle activity (p<0.05) with significant increases in lumbar spinae muscle activity (p<0.05). Also, muscle activity with the neutral head posture significantly increased more in the sternocleidomastoid muscle and lumbar spinae than that of the natural posture (p<0.05). Conclusions: Our study results suggest that in order to prevent musculoskeletal pain, the neutral head posture with use of laptops is effective in reducing load to the shoulders and vitalizing the postural muscles.

• The Journal of Korean Physical Therapy
• /
• v.32 no.4
• /
• pp.210-216
• /
• 2020

Purpose: This study examined the effects of curl-up using XCO^® on trunk muscle activation in healthy adults. Methods: This study design was a single-blind randomized controlled trial. Twelve participants were enrolled in this study. The subjects were instructed to perform curl-up exercise in STCU (straight curl-up), LTCU (left twist curl-up), RTCU (right twist curl-up), TWCU (twist curl-up), and PPCU (power push curl-up). Electromyography was used to assess the percent maximal voluntary isometric contraction (%MVIC) of the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and erector spinae (ES) muscles. The data were analyzed using two-way ANOVA with a repeated measure. The statistical significance level was set to α=0.05 Results: The IO showed significant differences in the main effect of the group and the interactions between the group and exercise (p<0.05). In particular, the IO represented the interactions between group and exercise in the RTCU and PPCU (p<0.05). The RA, EO, and ES did not show significant interactions between the group and exercise (p>0.05). The RA, IO, and EO showed significant differences in the main effect of the group (p<0.05). The EO showed a significant difference in the main effect of exercise (p<0.05). Conclusion: These findings suggest that XCO^® can be used to increase the muscle activation of the internal oblique, which is the lumbar stabilizing muscle, when XCO^® is combined in the curl-up exercise with rotation. In the future, research on the intensity, frequency, and duration of XCO^® exercise will be needed according to the individual characteristics and preferences.

• PNF and Movement
• /
• v.22 no.2
• /
• pp.181-189
• /
• 2024

Purpose: This study aimed to identify the effect of sling-applied plank exercise on the frequency, stiffness, and decrement of the rectus abdominis and longissimus muscles of the trunk according to the stability of the base of support. Methods: Thirty-three young adults volunteered to participate and were randomly assigned to one of three groups (SS, stable support; LES, lower extremity support; and ULES, upper and lower extremity support) according to the stability of the base of support. The muscular properties of the rectus abdominis and longissimus muscles during sling-assisted plank exercise according to the stability of the base of support. were measured by using Myoton PRO (Myoton AS, Tallinn, Estonia). Statistical analysis was performed MANOVA to determine the effect of sling-assisted plank exercise on the muscular properties of the rectus abdominis and longissimus muscles according to the stability of the base of support. Post hoc analysis was conducted using Bonferroni. The level of statistical significance was set at α = 0.05. Results: When comparing the muscular properties, the muscle frequency and stiffness of the left rectus abdominis of ULES were significantly decreased compared to that of SS (p < 0.05). In the measurement time, the muscle frequency and the muscle stiffness of the right rectus abdominis increased significantly after the intervention (p < 0.05). Conclusion: It was concluded that the more unstable the base of support (ULES), the higher the exercise strength, and the muscle frequency and stiffness decreased on the rectus abdominis at rest.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.26 no.1
• /
• pp.27-36
• /
• 2020

Background: Exercise in the quadruped position is performed to improve body and shoulder stability. This study examined the muscle activity of the trunk muscles according to the distance of the weight shift when lifting one leg in the quadruped position. Methods: Ten healthy 20 to 40 years old males were tested as subjects. All subjects moved their body weight to 0, 5, and 10cm on the opposite side of the leg lifter while maintaining the quadruped position. The surface electrodes recorded the electromyography data during the one leg lifting. Results: As the weight shift distance was increased, there was a significant difference in muscle activity of both serratus anterior, multifidus and internal oblique muscles (p<.05). Left and right serratus anterior and right internal oblique were most activated when weight shift distance was 0cm (p<.05). Conclusion: Shoulder and lumbar stabilization exercises should be applied in the absence of a weight shift distance during quadruped exercise.

• Korean Journal of Applied Biomechanics
• /
• v.14 no.2
• /
• pp.167-178
• /
• 2004

The purpose of this study was to describe and compare the selected electromyographical muscle activities of trunk and hip during Professional and Amateur golfer's Iron swing. Using surface electromyography, we evaluated muscle activities in 6 male professional golfers and 6 male amateur golfers during the golf iron swing. Surface electrodes were used to record the level of muscle activity in the right abdominal oblique, left abdominal oblique, right erector spinae, left erector spinae, right rectus abdominis, left rectus abdominis, right gluteus maximus, left gluteus maximus muscles during the golfer's swing. These signals were compared with IEMG(Integrated EMG) which was normalized by %RVC(Reference voluntary contraction). The golf swing was divided into three phases: take away, forward swing-acceleration, follow-through. We observed patterns of trunk muscle activity throughout three phases of the golf swing. The results can be summarized as follows: LES(Left Erector spinae) had statistically significant difference in take away and forward swing-acceleration phases. It was showed no significant difference in follow-through phase.

• Physical Therapy Korea
• /
• v.17 no.4
• /
• pp.1-7
• /
• 2010

The aim of this study was to investigate the effects of lumbar stabilization on both trunk and lower limb muscle activity and center of pressure (COP) in single leg standing. Surface electromyography (EMG) was used to collect muscle activity data, the mean velocity of COP was measured using a force plate, and a pressure biofeedback unit was used for lumbar stabilization training. The findings of this study are summarized as follows: 1) The EMG activity of the erector spinae decreased significantly and the activity of the rectus abdominis, internal oblique, external oblique, gluteus maximus, and gluteus medius increased significantly with lumbar stabilization single leg standing. 2) No differences in activity in the tibialis anterior, medial gastrocnemius, rectus femoris, and medial hamstrings were found with single leg standing. 3) The mean velocity of COP in the antero-posterior and medio-lateral directions in the lumbar stabilization single leg standing decreased significantly compared with the preferred single leg standing. The findings of this study therefore indicate that lumbar stabilization can facilitate the co-activation of deep stabilization and global muscles that improve postural control capability during single leg standing.

• International Journal of Internet, Broadcasting and Communication
• /
• v.13 no.1
• /
• pp.152-160
• /
• 2021

The purpose of this study was to investigate the difference in the number of repetitions and the change in electromyographic response during the maximum speed squat exercise according to the depth conditions and the maximum speed squat exercise according to the time of each depth. Ten men in their 20s were selected as subjects and the maximum speed squat was performed for one minute in three environmental conditions (ground, knee depth, waist depth). We found that the number of repetitions according to the depth of water showed a significant difference, and as a result of the post-mortem comparison, the number of repetitions was higher in the ground condition and the knee depth than in the waist depth. And the muscle activity of rectus abdominis, erector spinae, rectus femoris, biceps femoris was increased during ground squat exercise, activity of all muscle was decreased during knee depth squat exercise, and activity of rectus abdominis, erector spinae, biceps femoris, tibialis anterior, gastrocnemius was decreased during waist depth squat. In conclusion, muscle activity of lower extremities during squat exercise in underwater environment can be lowered as the depth of water is deep due to buoyancy, but muscle activity of trunk muscles can be increased rather due to the effect of viscosity and drag.

• Physical Therapy Korea
• /
• v.25 no.3
• /
• pp.1-11
• /
• 2018

Background: Lumbopelvic stability is highly important for exercise therapy for patients with low back pain and shoulder dysfunction. It can be attained using a pelvic compression belt. Previous studies showed that external pelvic compression (EPC) enhances form closure by reducing sacroiliac joint laxity and selectively strengthens force closure and motor control by reducing the compensatory activity of the stabilizer. In addition, when the pelvic compression belt was placed directly on the anterior superior iliac spine, the laxity of the sacroiliac cephalic joint could be significantly reduced. Objects: This study aimed to compare the effects of EPC on lumbopelvic and shoulder muscle surface electromyography (EMG) activities during push-up plus (PUP) and deadlift (DL) exercise, trunk extensor strength during DL exercise. Methods: Thirty-eight subjects (21 men and 17 women) volunteered to participate in this study. The subjects were instructed to perform PUP and DL with and without the EPC. EMG data were collect from serratus anterior (SA), pectoralis major (PM), erector spinae (ES), and multifidus (MF). Trunk extensor strength were tested in DL exercise. The data were collected during 3 repetitions of all exercise and the mean of root mean square was used for analysis. Results: The EMG activities of the SA and PM were significantly increased in PUP with pelvic compression as compared with PUP without pelvic compression (p<.05). In DL exercise, a significant improvement in trunk extensor strength was observed during DL exercise with pelvic compression (p<.05). Conclusion: The results of this study indicate that lumbopelvic stabilization reinforced with external pelvic compression may be propitious to strengthen PUP in more-active SA and PM muscles. Applying EPC can improve the trunk extensor strength during DL exercise. Our study shows that EPC was beneficial to improve the PUP and DL exercise efficiency.