• Physical Therapy Rehabilitation Science
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• v.11 no.2
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• pp.245-252
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• 2022

Objective: This study aimed to investigate the abdominal muscle activity difference while performing the abdominal bracing technique focusing on inspiration (abdominal bracing group), the general abdominal bracing technique (general bracing group), and the abdominal hollowing technique (abdominal hallowing group) Design: A cross-sectional study design. Methods: Thirty-three healthy participants were recruited for this study. The participants were allocated to 3 different groups; Abdominal bracing group, general bracing group, and abdominal hallowing group. The surface electromyography was placed over the rectus abdominis, external oblique, and internal oblique muscles to collect the activation of abdominal muscles during the trial. Results: The muscle activity of the abdominal bracing group and general bracing groups was significantly higher in all abdominal muscles than in the abdominal hollowing group (p<0.05) Both rectus abdominis and external oblique muscles showed higher muscle activations in the abdominal bracing group over the general bracing group (p<0.05). However, the ratio of bilateral external obliques and rectus abdominis to bilateral internal obliques was highest when the hollowing technique was applied (p<0.05). Conclusions: The results of study showed the abdominal bracing technique that emphasized inhalation rather than the abdominal hollowing technique or general abdominal bracing technique increased the activity of the abdominal muscles. Therefore, this study is considered to be a data for effective training if the abdominal bracing technique that emphasizes inhalation is applied as a method to increase the activation of the abdominal muscles.

• Physical Therapy Korea
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• v.24 no.1
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• pp.61-70
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• 2017

Background: Scapular winging is a prominence of the entire scapular medial border, mainly caused by insufficient activity of the serratus anterior (SA) and imbalance of scapulothoracic muscles. Push-up plus (PUP) exercise has been commonly used to increase SA muscle activity. The facilitation of abdominal muscle may affect scapular muscle activity by myofascial connections. Thus, the sequential activation of the turnk muscles is suggested to facilitate the transition of proper force from upper limb and restore force couple of scapular muscles. The abdominal drawing-in maneuver (ADIM) has been effective in improving activation of the deep trunk muscles during movement. Objects: The aim of this study was to determine the effect of ADIM on the activity of the upper trapezius (UT), lower trapezius (LT), and SA during PUP exercises in subjects with scapular winging. Methods: Fourteen men with scapular winging (determined as a of distance between the scapular medial border and thoracic wall over 3 cm) volunteered for our study. The subjects performed the PUP exercise with and without ADIM. Surface electromyography was used to collect the electromyography data of the UT, LT, and SA. A scapulometer was used to measure the amount of scapular winging. Results: SA activity was significantly greater and scapular winging significantly lower during the PUP exercise with ADIM than during those without ADIM. Conclusion: PUP exercise with ADIM can be used as an beneficial method to improve SA activation and to reduce the amount of scapular winging in subjects with scapular winging.

• The Journal of Korean Physical Therapy
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• v.23 no.1
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• pp.1-5
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• 2011

Purpose: The purpose of this study was to investigate changes in muscle activation associated with foot position during a sit-to-stand exercise among normally healthy elderly subjects. Methods: Eight subjects (male=3; female=5; mean age=$70.13{\pm}{\pm}2.53$years) were recruited.The activation of six muscles (neck extensor; lumbar extensor; hamstring; rectus femoris; gastrocnemius; tibialis anterior) was measured by surface EMG (TeleMyo 2400T G2, Noraxon Inc., USA) during a sit-to-stand protocol under three different foot positions (ankle dorsiflexion of 0, 15, or 30 degrees). Results: Muscle activation of the neck extensor and hamstring was decreased according to the change in foot position (p<0.05), but activation of the rectus femoris was increased (p<0.05). Muscle activation of the neck extensor was significantly different between 0 and 15 degrees (p<0.05). Muscle activation of the hamstring was significantly different between 0 and 15 degrees and between 0 and 30 degrees (p<0.05). Muscle activation of the rectus femoris was significantly different between 0 and 30 degrees and between 15 and 30 degrees (p<0.05). However, activation of lumbar extensor, gastrocnemius and tibialis anterior muscles did not significantly differ between foot positions. Conclusion: These findings suggest that muscle activation during a sit-to-stand movement differs depending on foot position. We believe that these differences should be considered when educating the elderly regarding proper body movements.

• Physical Therapy Korea
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• v.31 no.1
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• pp.18-28
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• 2024

Background: Lateral instability of the ankle is one of the most common causes of musculoskeletal ankle injuries. The peroneus longus (PL) and peroneus brevis (PB) contribute to ankle stability. In early rehabilitation, isometric exercises have been selected for improvement of ankle stability. To effectively train the peroneal muscles during eversion, it is important to consider ankle and body posture. Objects: This study aimed to compare activation of the PL, PB, and biceps femoris (BF) muscles during eversion in different ankle postures (neutral [N], plantarflexed [PF]) and body postures (sitting and side-lying). Methods: Thirty healthy individuals with no history of lateral ankle sprains within the last 6 months were included in the study. Maximal isometric strength of eversion and muscle activation were measured simultaneously. Muscle activation at submaximal eversion was divided by the highest value obtained from maximal isometric eversion among the four postures (percent maximal voluntary isometric contraction [%MVIC]). To examine the differences in muscle activation depending on posture, a 2 × 2 repeated measures analysis of variance (ANOVA) was conducted. Results: There were significant interaction effects of ankle and body postures on PL muscle activation and evertor strength (p < 0.05). The PL muscle activation showed a significantly greater difference in the side-lying and PF conditions than in the sitting and N conditions (p < 0.05). Evertor strength was greater in the N compared to the PF condition regardless of body posture (p < 0.05). In the case of PB and BF muscle activation, only the main effects of ankle and body posture were observed (p < 0.05). Conclusion: Among the four postures, the side-lying-PF posture produced the highest muscle activation. The side-lying-PF posture may be preferred for effective peroneal muscle exercises, even when considering the BF muscle.

• Physical Therapy Rehabilitation Science
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• v.10 no.4
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• pp.444-449
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• 2021

Objective: The purpose of this study is to observe the change in the thickness of abdominal muscles when electrical muscle stimulation (EMS) is applied to the abdomen during rest and abdominal muscle exercise to investigate the effect of EMS applied to the abdomen on the superficial and deep muscles thickness. Design: Cross sectional design. Methods: Twenty healthy subjects participated in this study. Subjects were performed resting position, resting position with EMS, curl-up and curl-up with EMS. The electrode of the EMS belt is attached to the abdominal wall between the 12th rib and iliac crest. The thickness of abdominal muscles including rectus abdominis (RA), external oblique (EO), internal oblique (IO), and transverse abdominis (TrA) were captured in each position by ultrasound image during expiration. All subjects were performed four positions randomly. Data were analyzed using repeated ANOVA with the level of significance set at 𝛼=0.05. Results: The muscle thickness of RA, EO, IO and TrA were significantly different at each position (p<0.05). The thickness of all abdominal muscles increased significantly when curl-up than curl-up with EMS. Both RA and EO thickness were significantly increased at resting position than resting position and EMS were combined(p<0.05). But IO and TrA thickness were decreased at resting position when EMS were combined. Conclusions: The results suggest that EMS activates superficial abdominal muscles RA and EO. Therefore, abdominal strengthening exercise combined EMS can activate abdominal muscles and can be applied to various patients and rehabilitation in clinical practice.

• PNF and Movement
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• v.12 no.1
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• pp.39-43
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• 2014

Purpose: This study was to examine lateral abdominal muscle activation during maximum expiration exercise between healthy and chronic low back pain(CLBP) patients. Methods: The subjects were 16 CLBP patients and 16 healthy people between the ages of 22 and 53. The thickness of the abdominal muscles was measured using ultrasonography(LOGIQ Book XP, GE, USA). We instructed the subjects how to perform the exercises and measured changes in thickness of the transversus abdominis(TrA) and internal oblique(IO) muscles during the maximum expiration. The main outcome variables were the ratios of the TrA and IO thickness during the exercise versus in the relaxed position(TrA and IO activation ratios). Results: There were significant differences between CLBP patients and healthy subjects for TrA in the relaxed position. However there was no difference in the ratio of change in the muscle activity(TrA, IO). Conclusion: These findings, CLBP patients exhibited atrophy of the TrA muscle, but voluntary TrA muscle activation was similar to that of the normal subjects. Therefore, this exercise could be used during core strengthening in CLBP patients.

• PNF and Movement
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• v.20 no.1
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• pp.51-58
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• 2022

Purpose: The purpose of this study was to investigate the effect of thoracic-lumbar dissociation motion and slump motion on thoracic-lumbar erector spinae and rectus abdominis muscle activity. Methods: Seventeen healthy adult volunteers participated in this study. All participants performed two motions (thoracic-lumbar dissociation motion, slump motion). Muscle activation during the two motions was measured using a surface electromyography device. The data from this were collected from the iliocostalis thoracis, iliocostalis lumborum, and rectus abdominis. The activities of these muscles before and after each motion were then compared. Results: The iliocostalis thoracis activation was significantly greater during the thoracic-lumbar dissociation motion than during the slump motion (p <0.05). The iliocostalis lumborum activation was greater during the slump motion than during the thoracic-lumbar dissociation motion (p <0.05). The rectus abdominis activation was lesser during the slump motion than during the thoracic-lumbar dissociation motion (p <0.05). Conclusion: This study confirmed that individual contraction of the erector spinae muscles is possible during thoracic-lumbar dissociation motion, which increases the stability of the thoracic spine. In addition, this motion could improve control of the rectus abdominis. Therefore, thoracic-lumbar dissociation motion should be considered for rehabilitation programs for patients with kyphosis and back pain.

• Physical Therapy Rehabilitation Science
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• v.5 no.2
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• pp.70-77
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• 2016

Objective: The purpose of this study was to compare the activation of trunk and gluteal muscles during bridge exercises with a sling (BS), single-legged bridge exercise with a sling (SBS), single-legged bridge exercise (SB), and general bridge exercise (GB). Design: Cross-sectional study. Methods: Twenty-five healthy participants (19 males and 6 females, aged 27.8 [4.78]) voluntarily participated in this study. In the bridging exercise, each subject lifted their pelvis with their legs and feet in contact with the sling or normal surface. The electrical activities of the erector spinae (ES), gluteus maximus (GM), external oblique (EO), and internal oblique (IO) muscles during the bridging exercises on the 2 surfaces were measured using surface electromyography. Subjects practiced each of the four bridge condition three times in random order and average values were obtained. Results: On the ipsilateral side, activities of the IO, EO, and ES during SBS was significantly higher than those during BS, SB, and GB (p<0.05). Activities of the IO and EO during SB was significantly higher than those during BS and GB (p<0.05). On the contralateral side, activities of the GM and EO during SB and SBS was significantly higher than that during BS and GB (p<0.05). These results verify the theory that the use of sling and single leg lift increases the activation trunk and gluteal muscles during bridging exercises. Conclusions: The single-legged bridge exercise with a sling can be recommended as an effective method to facilitate trunk and gluteal muscle activities.

• Journal of Korean Physical Therapy Science
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• v.27 no.1
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• pp.51-55
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• 2020

Background: A typical plank exercise (PE) strengthens the core muscles, stabilizes the spinal column, and provides stability around the pelvis and trunk when the trunk is aligned. However, because PE require that the hip joint be kept straight, they can activate the hamstring (HAM). Excessive HAM activation can induce tightness, which may cause low back pain. Therefore, it is necessary to explore PE methods that can minimize HAM activity while maximizing core muscle activity. Design: Cross-sectional study. Methods: This study included 30 healthy adults as subjects. We measured the activity of the HAM and the erector spinae (ES), rectus abdominis (RA), and external oblique (EO) muscles using surface electromyography during three PEs (typical PE, PE with balance pad, and PE with sling). Results: The RA, EO, and ES showed the highest muscular activity during PE with balance pad and the lowest during PE with sling; however, the differences were not significant. The HAM showed lower activity during PE with sling than during the other two PEs; however, these differences were also not significant. Conclusion: Although HAM activation was not significantly difference among PE positions, we should recognize altering activation of core and hamstring muscle according to PE postures.

• Korean Journal of Applied Biomechanics
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• v.29 no.2
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• pp.79-88
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• 2019

Objective: The aim of this study was to determine the peak torques of the knee and ankle joint and local stability of the lower extremity's joints, and muscle activation patterns of the lower extremity's muscles between fallers and non-fallers in the elderly women during walking. Method: Four elderly women (age: $74.5{\pm}5.2yrs.$; height: $152.1{\pm}5.6cm$; mass: $55.3{\pm}5.4kg$; preference walking speed: $1.19{\pm}0.06m/s$) who experienced falls within six months since experiment had been conducted (falls group) and thirty-six subjects ($74.2{\pm}3.09yrs.$; height: $153.6{\pm}4.9cm$; mass: $56.7{\pm}6.4kg$; preference walking speed: $1.24{\pm}0.10m/s$) who had no experience in falls (non-falls group) within this periods participated in this study. They were measured torque peaks of the knee and ankle joint using a Human Norm and while they were walking on a treadmill at their natural pace, kinematic variables and EMG signals were collected with using a 3-D motion capture system and a wireless EMG system, respectively. Lyapunov Exponent (LyE) was determined to observe the dynamic local stability of the lower extremity's joints, and muscles activation and their co-contraction index were also analysed from EMG signals. Hypotheses between falls and non-falls group were tested using paired t-test and Mann-Whitey. Level of significance was set at p<.05. Results: Local dynamic stability in the adduction-abduction movement of the knee joint was significantly lower in falling group than non-falling group (p<.05). Conclusion: In conclusion, muscles which act on the abduction-adduction movement of the knee joint need to be strengthened to prevent from potential falls during walking. However, a small number of samples for fallers make it difficult to generalize the results of this study.