• Journal of Korean Physical Therapy Science
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• v.19 no.2
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• pp.1-7
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• 2012

Purpose : The purpose of this study was to investigate the effect of different heel height on the electromyographic (EMG) activity in Rectus abdominis (RA) and Erector spinae (ES) during gait activity. Methods : A repeated measures design was used. 33 healthy females carried out a standardized gait activity under 3 conditions; with heel wedges of 1, 7, and 12cm in height. EMG activity was recorded from RA and ES during the activity. Data was analysed using the repeated one-way ANOVA. Results : First, as the shoe-heel height was getting higher, change of muscle activation indicated the statistically significant difference in rectus abdominis(p<0.05). Second, as the shoe-heel height was getting higher, change of muscle activation indicated the statistically significant difference in erector spinae(p<0.05). Conclusion : We found that as heel height increased, there was an increase in EMG activity in both RA and ES. This indicated that no RA : ES imbalance was elicited. This study provides information that will inform future research on how heel height affects muscle activity around the trunk.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.10
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• pp.927-932
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• 2010

Estimation methods of motion intention from bio-signal present challenges in man machine interaction(MMI) to offer user's command to machine without control of any devices. Measurements of meaningful bio-signals that contain the motion intention and motion estimation methods from bio-signal are important issues for accurate and safe interaction. This paper proposes a novel motion estimation sensor based on a geometrical muscle changes, and a motion estimation method using the sensor. For estimation of the motion, we measure the circumference change of the muscle which is proportional to muscle activation level using a flexible piezoelectric cable (pMAS, piezo muscle activation sensor), designed in band type. The pMAS measures variations of the cable band that originate from circumference changes of muscle bundles. Moreover, we estimate the elbow motion by applying the sensor to upper limb with least square method. The proposed sensor and prediction method are simple to use so that they can be used to motion prediction device and methods in rehabilitation and sports fields.

• The Journal of Korean Physical Therapy
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• v.32 no.2
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• pp.75-79
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• 2020

Purpose: This study analyzed the immediate effects of intra-abdominal pressure with visual feedback on the muscle activation of the upper trapezius and sternomastoid during natural inspiration and forced inspiration in individuals with costal respiration. Methods: The eighteen individuals with upper costal breathing pattern participated in this study. Surface electromyography was used to analyze the muscle activity of the upper trapezius and sternomastoid during natural inspiration and forced inspiration before and after intra-abdominal pressure. Results: A significant difference in muscle activation was observed with the muscle type, inspiration type, and test session (p<0.05). The muscle activities of the sternomastoid and upper trapezius decreased significantly during forced inspiration after intra-abdominal pressure training (p<0.05). On the other hand, there was no significant difference during natural inspiration in both muscles (p>0.05). A comparison of the difference between the pre-test and post-test during forced inspiration revealed the upper trapezius to be significantly larger than the sternomastoid (p<0.05). No significant difference was noted during natural inspiration (p>0.05). Conclusion: The intra-abdominal pressure has positive effects on correcting the breathing patterns in individuals with costal respiration.

• Physical Therapy Korea
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• v.16 no.2
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• pp.31-39
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• 2009

This study is performed to investigate the difference of the spinal stability system with and without low back pain. There were 9 participants with low back pain and 9 asymptomatic subjects to be recruited, they were measured thoracic and lumbar curvature, trunk muscle activation in upright sitting postures and slump sitting, back muscle endurance, and lumbar proprioception. Spinal curvature and surface electromyography of 4 trunk muscles were measured in an upright sitting postures and slump sitting in 18 subjects. The result of the study was that there were significant differences between the groups in spinal curvature (p<.05), significantly higher external oblique activity and less internal oblique in the low back pain group than the healthy subjects (p<.05), and significantly less proprioception in the low back pain group (p<.05). But there was not a significant difference between the trunk muscle endurance groups. According to the result, the low back pain group had greater thoracic extension and higher global muscle activity in the upright sitting posture and less proprioception. This study was useful to suggest postural training for normal muscle activation, selective muscle strengthening to prevent chronic deterioration, and helpful in making a treatment plan to indicate a synthetic care method that includes increasing proprioception.

• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.115-124
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• 2008

The purpose of this study was to know influenced on the change of Oswestry back pain disability index(OBPDI), isometric muscle power(IMP), muscular activation with chronic low back pain(CLBP) patients after Trunk Stabilization Exercise. Intervention was provided 6 weeks(5 days a week). Muscular activation was measured during IMP(Muscles : transversus abdominis : TA, internal obliqus : IO, external obliqus : EO, rectus abdominis : RA and erector spinae: ES). The results were as follows. 1. OBPDI about the MBE and the SE groups had effective decrease pain and disability. 2. IMP of intervention after the MBE and the SE groups had effective improve muscle power. 3. Muscle activation during IMP of intervention after was : TA, IO, RA had increase in the MBE and the SE groups. EO muscle activation during IMP of intervention after had increase only MBE groups. This shows that the MBE and the SE groups had effective increase because it has effective improve muscle power. Therefore, this study shows ￡hat trunk stabilization exercise program influenced on the change of OBPDI, IMP, muscular activation with CLBP patients.

• Physical Therapy Korea
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• v.10 no.2
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• pp.11-22
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• 2003

The purpose of this study was to analyze the effects of three different pelvic tilts on a sit-to-stand (STS) and to suggest a new assessment approach based on biomechanical analysis. The three difrent pelvic tilts were: (1) comfortable pelvic tilt sit-to-stand (CPT STS), (2) posterior pelvic tilt sit-to-stand (PPT STS) and (3) anterior pelvic tilt sit-to-stand (APT STS). To determine the onset time of muscle contraction surface electrodes were applied to the rectus femoris muscle (RF), vastus lateralis muscle (VL), biceps femoris muscle (BF), tibialis anterior muscle (TA), gastrocnemius muscle (GCM), and soleus muscle (SOL). The ICC was used for functional linkage analysis. The findings of this study were as follows. First, significant differences were found in kinematic variables and in muscle activation pattern among the three activities. Second, the results of functional integrated analysis revealed that recruited muscle activation patterns changed when the thigh-off was viewed as a reference point. Third, there were independent functional units between the thigh-off and the VL and between the thigh-off and the RF in the functional linkage analysis. The VL and RF acted as prime mover muscles, and more postural adjustment muscle recruitment was required as the demand of postural muscle control increased (PPT STS, APT STS, and CPT STS in order). In conclusion, the findings of this study suggest the following evaluative and therapeutic approach for STS activity. APT STS can be introduced for movement efficiency and functional advantage when abnormal STS is treated. However, excessive APT would change the muscle activation patterns of BF and SOL and require additional postural muscle control to cause abnormal control patterns.

• PNF and Movement
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• v.20 no.3
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• pp.341-349
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• 2022

Purpose: The purpose of this study is to compare the muscle activity of the hip abductors and the ratio between the hip abductor muscle group according to the range of hip abduction during the clam exercise. Methods: This study was conducted on 18 healthy men in their aged 20 to 29 who had not been diagnosed with spine-related diseases. The subjects performed a clam exercise without rotation of the pelvis in a state of 60° hip flexion and 90° knee joint flexion in the side-lying position. Using Myomotion equipment and EMG, the muscle activity of the hip abductor muscles and the activity ratio between the hip abductor muscle group were measured during the clam exercise by dividing the range into initial, mid-range, and terminal sections. Repeated measures analysis of variants was employed to compare the activity and use of hip abductor muscles according to range of motion during the clam exercise. Results: Gluteus medius muscle activation was significantly increased in the comparison of muscle activity in the initial, mid-range, and terminal sections of hip abduction. Tensor fasciae latae muscle activation was significantly increased in the comparison of muscle activity in all range of motion sections as well. The gluteus medius-tensor fasciae latae muscle activation ratio was significantly increased in the terminal section compared to the initial section. Conclusion: The gluteus medius and tensor fasciae latae had higher muscle activities as they approached the terminal section during the clam exercise, and the hip abduction activity ratio of the gluteus medius and tensor fasciae latae was higher as the range of motion approached the terminal section.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.237-244
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• 2009

The purpose of this study was to investigate the changing plantar foot pressure and muscle activation of neck, lumbar and low limb by different way of the using carrier during walking. Twenty healthy and young females who brought up infants and had no musculoskeletal disorders of neck, lumbar and low limb were instructed to perform plantar foot pressure and muscle activation of neck, lumbar and low limb during different ways of the using the carrier and walking. Plantar foot pressures were recorded by RS-scan system(RS scan Ltd, German), muscle activation were recorded by ProComp infinitiTM(Thought Technology Ltd, Canada). The data collected by each way of the using carrier and One-way ANOVA was used to analyze. The results indicated that there was a significant increase on erector spinae muscle activation and pressure of great toe zone by using anterior carrier and there was a increase on activation of paraspinal muscle and metatarsal zone by using posterior carrier. Therefore, the way of using carrier could be influenced upon structure and function of the foot and muscle activation.

• Korean Journal of Applied Biomechanics
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• v.26 no.1
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• pp.135-142
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• 2016

Objective: The purpose of this study was to investigate the acute effect of walking on high heels on the behavior of fascicle length and activation of the lower limb muscles. Methods: Twelve healthy inexperienced high heel wearers (age: $23.1{\pm}2.0yr$, height: $162.4{\pm}4.9cm$, weight: $54.4{\pm}8.5kg$) participated in this study. They walked in high heels (7 cm) and barefoot on a treadmill at their preferred speed. During the gait analysis, the lower limb joint kinematics were obtained using a motion analysis system. In addition, the changes in fascicle length and the level of activation of the medial gastrocnemius (MG) were simultaneously monitored using a real-time ultrasound imaging technique and surface electromyography, respectively. Results: The results of this study show that the MG fascicle operates at a significantly shorter length in high heel walking ($37.64{\pm}8.59mm$ to $43.99{\pm}8.66mm$) in comparison with barefoot walking ($48.26{\pm}9.02mm$ to $53.99{\pm}8.54mm$) (p < .05). In addition, the MG fascicle underwent lengthening during high heel walking with relatively low muscle activation while it remained isometric during barefoot walking with relatively high muscle activation. Conclusion: Wearing high heels alters the operating range of the MG fascicle length and the pattern of muscle activation, suggesting that prolonged wearing of high heels might induce structural alterations of the MG that, in turn, hinder normal functioning of the MG muscle during walking.

• The Journal of Korean Physical Therapy
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• v.33 no.1
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• pp.1-6
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• 2021

Purpose: This study examined the effects of heel insoles on the static balance and leg muscle activity and posture control strategy during external perturbation. Methods: Thirty healthy young men participated in the study. The subjects underwent two experimental conditions: 1) no heel insole condition (0cm) and 2) wearing heel insole condition (5cm). The static balance was measured using an I-Balance device, which measured the change in the center of gravity (COG). The onset time of muscle activation and muscle activation of the erector spinae (ES), hamstring (HAM), gastrocnemius (GCM) were measured using surface EMG electrodes to determine the change in posture control strategy during external perturbation. Results: The speed and distance of COG were significantly higher in the wearing heel insoles condition than the no heel insole condition (p<0.05). In addition, significant differences in the onset time of the GCM, HAM, and ES muscle activation were observed when there was no heel insole condition during external perturbation (p<0.017). On the other hand, no significant differences in the onset time of muscle activation were observed between GCM and HAM when wearing the heel insole condition during external perturbation (p<0.017). Moreover, muscle activation of the GCM was significantly higher in the wearing heel insoles condition than the no heel insole condition during external perturbation (p<0.05). Conclusion: These findings suggest that heel insoles may have disadvantages, and increased efforts are needed to maintain balance and change the posture control strategy during external perturbation.