The effects of prone bridge exercise on trunk muscle thickness in chronic low back pain patients

[Purpose] This study aimed to investigate the effects of prone bridge exercise on trunk muscle thickness. [Subjects and Methods] Thirty-seven chronic low back pain patients participated in this study. Each participant was randomly assigned to one of three exercise groups, namely, a prone bridge exercise group, supine bridge exercise on a Swiss ball group, and supine bridge exercise group. The thicknesses of the transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) were measured using ultrasound. [Results] After eight weeks of training, the three groups showed significant increases in the thicknesses of the TrA, IO, and EO. Among the groups, TrA and IO showed significantly different muscle thicknesses. [Conclusion] The prone bridge exercise significantly affected the thicknesses of the TrA, IO, and EO unlike the supine bridge exercises. Based on the results of this study, the prone bridge exercise is a more effective method to improve trunk stability than conventional supine bridge exercises.Key words: Bridge exercise, Muscle thickness, Chronic low back pain     

Comparison of the Changes in Thickness of the Abdominal Wall Muscles of Stroke Patients According to the Duration of Their Illness as Observed Using Ultrasonographic Images

[Purpose] This study was conducted in order to investigate the importance of trunk muscle strength in stroke patients. By comparing the thicknesses of the abdominal wall muscles through ultrasonography, relative to the duration of illness, the results of the objective data were applied. [Methods] Thirty stroke patients were divided into three groups including an acute phase group participating in the study within 1 month after the onset of a stroke (n=10), a subacute phase group participating less than 6 months (n=10) after a stroke, and a chronic phase group participating more than 6 months (n=10) after suffering a stroke. The thicknesses of the transversus abdominis muscles (TrA), internal oblique muscle (IO), and the external oblique muscle (EO) were measured at rest and during abdominal draw-in maneuver (ADIM) in a supine hook-lying position, and their differences were compared. [Results] The results showed that, in comparison of the thicknesses of the paretic and nonparetic sides, the TrA of the subacute phase and chronic phase groups showed significant differences. In addition, the IO of the subacute phase group and the EO of the chronic phase groups also showed significant differences. [Conclusion] According to the duration of illness in stroke patients, the abdominal wall muscles become noticeably infirm and asymmetric. By improving their symmetry, the functions of the trunk muscles can be recovered.Key words: Stroke, Sonographic image, Abdominal wall muscles     

Reliability of Ultrasound Imaging of the Transversus Deep Abdominial, Internal Oblique and External Oblique Muscles of Patients with Low Back Pain Performing the Drawing-in Maneuver

[Purpose] The purpose of this study was to investigate the reliability of ultrasound imaging (USI) measurements of muscle thicknesses of patients with low back pain (LBP) performing the abdominal drawing-in maneuver (ADIM) [Subjects] Twenty patients with LBP were the subjects. [Methods] Muscle thickness measurements of transversus abdominis (Tra), internal obliques (IO), and external obliques (EO) muscles were measured using ultrasound imaging at rest and during performance of the ADIM. [Results] The intra-examiner reliability estimates ranged from 0.55 to 0.97 in the rest position, and from 0.82 to 0.95 during ADIM. The inter-examiner reliability estimates ranged from 0.77 to 0.98 in the rest position, and from 0.86 to 0.98 during ADIM. [Conclusion] ADIM thickness measurements of the TrA, IO, and EO muscles in patients with LBP based on the mean of 2 measures are highly reliable when taken by a single examiner and adequately reliable when taken by different examiners.Key words: Reliability, Abdominal drawing-in maneuver, Ultrasound imaging     

Effects of Different Types of Contraction in Abdominal Bracing on the Asymmetry of Left and Right Abdominal Muscles

[Purpose] The purpose of this study was to investigate the effective strength levels of abdominal muscle contraction using the bracing contraction method. [Subjects] The experiment was conducted with 31 healthy male (M=15) and female (F=16) adults attending D University in Busan; all participants had less than obesity level BMI (BMI<30). [Methods] Bracing contraction was performed by the subjects in the hook-lying position at maximum and minimum pressure levels, five times each, using a Pressure Biofeedback Unit (PBU), and the mean measurement value was calculated. The maximum pressure level was set at 100% and the half maximum pressure level was set at 50%. Each subject’s left and right abdominal muscle thicknesses were then measured by ultrasound imaging in each state: at rest, 100% contraction, and 50% contraction. [Results] No significant differences were found between the left and right sides of the transversus abdominis (TrA) at rest, 50%, or 100% contraction. The external oblique abdominis (EO) and internal oblique abdominis (IO) showed no significant difference at rest or at the 50% contraction. However, a significant difference was noted at 100% contraction for the EO and IO. [Conclusion] Application of abdominal contraction using bracing can achieve symmetry in the left and right abdominal muscles at less than the maximum contractile strength. The occurrence of asymmetry in the left and right abdominal muscles at the maximum contractile strength suggests that the most suitable contractile strength in this exercise is less than the maximum contractile strength.Key words: Abdominal bracing, Symmetry, Ultrasound imaging     

What is a Suitable Pressure for the Abdominal Drawing-in Maneuver in the Supine Position Using a Pressure Biofeedback Unit?

[Purpose] The aim of this study was to determine the appropriate pressure variation for performing a successful abdominal drawing-in maneuver (ADIM). The abdominal muscle thickness variations and contraction ratios were examined in relation to pressure variations using a Pressure Biofeedback Unit (PBU) during an ADIM in the supine position. [Methods] The PBU was placed identically between the lumbar lordosis of 20 healthy subjects (12 males and 8 females) and the pressure of the PBU was maintained at 40 mmHg. Then, while the subjects performed ADIM at four random pressure variations (0, 2, 4, or 6 mmHg), the thicknesses of the transversus abdominis (TrA), the internal oblique abdominal muscle (IO), and the external oblique abdominal muscle (EO) were measured using ultrasonography. [Results] Pressure increases of 0–2 mmHg resulted in significant decreases in IO and EO thicknesses compared to pressure increases of 6 mmHg. Increases of 0–2 mmHg also resulted in significant decreases in IO+EO and EO contraction ratios compared to pressure increases of 6 mmHg, while the preferential activation ratio of the TrA was significantly increased. [Conclusion] Compared to the other pressure increases, an increase of 0–2 mmHg effectively regulated the thicknesses and contraction ratios of superficial muscles such as IO and EO, rather than the thickness and contraction ratio of the TrA, showing high and indirect preferential activation ratios for TrA. Therefore, for successful ADIM, rather than using large PBU pressure increases, exercises that promote slight increases of around 0–2 mmHg from a baseline of 40 mmHg are desirable.Key words: Pressure biofeedback unit, Abdominal drawing-in maneuver, Pressure variation     

The Effect of Abdominal Bracing in Combination with Low Extremity Movements on Changes in Thickness of Abdominal Muscles and Lumbar Strength for Low Back Pain

[Purpose] The purpose of this study was to investigate the effects of abdominal bracing with low extremity movement on changes in thickness of abdominal muscles and lumbar strength. [Subjects] Sixteen patients with chronic low back pain were randomly assigned to two groups: an abdominal bracing with active straight leg raise (ABSLR) group and abdominal bracing with ankle dorsiflexion (ABDF) group. [Methods] All subjects were evaluated for their abdominal muscle strength using a MedX Lumbar Extension Machine and thickness of external oblique (EO), internal oblique (IO), and transverse abdominis (TrA) muscles using rehabilitative ultrasound imaging. Subjects in both groups were instructed to perform Abdominal bracing (AB). Simultaneously, those in the ABSLR group performed active SLR, and those in the ABDF group performed ankle dorsiflexion. [Results] In comparison between the ABSLR and ABDF groups, significant differences in the thickness of the IO and TrA muscles were observed after the intervention in the ABSLR group. Also, lumbar strength was showed a significant increase in both groups after interventions. [Conclusion] The results of this study demonstrated that ABSLR is a more effective method than ABDF for improvement of abdominal stabilization by increasing the thicknesses of the TrA and IO.Key words: Abdominal bracing, Transverse abdominis, Ultrasonography     

Ultrasound evaluation of the symmetry of abdominal muscles in mild adolescent idiopathic scoliosis

[Purpose] The objective of the study was to evaluate the symmetry of the thickness of the abdominal muscles at rest and while standing in patients with adolescent idiopathic scoliosis. [Subjects and Methods] An ultrasound assessment was performed of the side-to-side differences of the external oblique (EO), internal oblique (IO), and transversus abdominalis (TrA) muscles in the supine and standing positions in adolescent idiopathic scoliosis (AIS) and control groups. [Results] In the AIS group, 64.3% of the patients had left scoliosis with a mean Cobb angle of 10.7°, and 35.7% of the patients had right scoliosis with a mean Cobb angle of 10°. In the supine position, the thickness asymmetry of the TrA was greater in the AIS compared with the control group by an average of 14% (95% CI 3.9–24.2). [Conclusion] Among the abdominal muscles examined, patients with AIS exhibited more asymmetry only for the TrA. In the standing position, the TrA was as symmetric in the patients as in the control group. Mild scoliosis has no impact on the symmetry of the thickness of the OE and OI in the supine and standing positions. The direction of curvature had no effect on the symmetry of the abdominal muscles studied.Key words: Adolescent, Idiopathic scoliosis     

Effects of performing an abdominal hollowing exercise on trunk muscle activity during curl-up exercise on an unstable surface

[Purpose] The purpose of this study was to investigate the effects of the abdominal hollowing exercise on trunk muscle activity during the curl-up exercise on an unstable surface by measuring electromyography (EMG) activity. [Subjects] Fourteen young healthy adults (nine male, five female) voluntarily participated in this study. [Methods] Each subject was asked to perform a curl-up exercise on two supporting surfaces (stable and unstable surfaces) combined with the abdominal hollowing exercise on an unstable surface. The muscle activities of the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and transverse abdominis (TrA) were measured using surface EMG during performance of the curl-up exercise. [Results] The EMG activity of the RA and EO was significantly higher on an unstable surface than on a stable surface during the curl-up exercise. The EMG activities of the TrA and IO were greater in combination with the abdominal hollowing exercise on an unstable surface than during the curl-up exercise on both a stable and unstable surface. [Conclusion] These findings suggest that the local trunk muscle activity during the curl-up exercise is more strongly affected by combination with the abdominal hollowing exercise than by performance on an unstable supporting surface.Key words: Abdominal hollowing exercise, Curl-up exercise, Unstable surface     

The Influence of Dual Pressure Biofeedback Units on Pelvic Rotation and Abdominal Muscle Activity during the Active Straight Leg Raise in Women with Chronic Lower Back Pain

[Purpose] This study was performed to assess the influence of applying dual pressure biofeedback units (DPBUs) on the angle of pelvic rotation and abdominal muscle activity during the active straight leg raise (ASLR). [Subjects] Seventeen patients with low-back pain (LBP) participated in this study. [Methods] The subjects were asked to perform an active straight leg raise (ASLR) without a PBU, with a single PBU, and with DPBUs. The angles of pelvic rotation were measured using a three-dimensional motion-analysis system, and the muscle activity of the bilateral internal oblique abdominis (IO), external oblique abdominis (EO), and rectus abdominis (RA) was recorded using surface electromyography (EMG). One-way repeated-measures ANOVA was performed to determine the rotation angles and muscle activity under the three conditions. [Results] The EMG activity of the ipsilateral IO, contralateral EO, and bilateral RA was greater and pelvic rotation was lower with the DPBUs than with no PBU or a single PBU. [Conclusion] The results of this study suggest that applying DPBUs during ASLR is effective in decreasing unwanted pelvic rotation and increasing abdominal muscle activity in women with chronic low back pain.Key words: Active straight leg raise, Pelvic rotation, Pressure biofeedback unit     

The Relationship of Abdominal Muscles Balance and Body Balance

This study aimed to identify what impact the thickness differences between the leftside and rightside transversus abdominis (TrA), internal obliquus (IO) and external obliquus (EO) have on balance ability in the abdominal drawing-in maneuver (ADIM) and resting postures. [Subjects and Methods] In this study, 41 young adults were asked to adopt a resting posture and to perform ADIM. The thicknesses of the abdominal muscles (TrA, IO, EO) were measured using ultrasound imaging, Then balance ability was measured, so that a comparative analysis could be carried out. [Results] According to the results, the thicknesses of TrA and IO very significantly increased when ADIM was performed. The changes in thickness of the muscles on the left and right sides showed no significant correlations with balance ability. [Conclusion] According to the study results, the difference in thickness between the left and right side muscles in a normal person is small (symmetric), and the differences in the thickness of TrA and IO on the left and right side reduced when the ADIM, which is a re-education method for abdominal muscles was performed. Therefore, we consider that the ADIM should be used in future clinical trials to induce symmetric contraction of the abdominal muscles. Also, the correlation results of muscle balance and body balance can be used as empirical data.Key words: Ultrasound, Abdominal muscle, Imbalance     

Changes in the Activities of the Trunk Muscles in Different Kinds of Bridging Exercises

[Purpose] The purpose of this study was to examine the effects of different types of bridging exercises on the activities of the trunk muscles. [Methods] Twenty-four students participated in this experiment. The activities of the internal oblique (IO), external oblique (EO), rectus abdominis (RA), and erector spinae (ES) muscles were measured in four different bridging exercises. [Results] There were significant differences in the IO, EO, RA, and ES among the four kinds of bridging exercise. The activities of IO, EO and RA were the highest in prone bridging (exercise 4), followed by unilateral bridging (exercise 3), and supine bridging on balance pads (exercise 2). In conventional bridging (exercise 1), the activities of IO, EO, and RA were the lowest. The activity of ES was the highest in exercise 3 followed by exercises 2 and 1. The activity of ES was the lowest than in exercise 1. [Conclusions] Bridging exercise in the prone position may be a more effective method of enhancing trunk muscle activities exercises in other positions.Key words: Bridge exercise, Muscle activity, EMG     

The influences of position and forced respiratory maneuvers on spinal stability muscles

[Purpose] The purposes of this study were to investigate the influences of position on %MVIC of spinal stability muscles to establish for the most effective breathing pattern for activation of spinal stability muscles in order to provide an additional treatment method for use in spinal stability exercise programs. [Subjects and Methods] Thirty-three healthy subjects performed quiet breathing and four different forced respiratory maneuvers (FRM); [pursed lip breathing (PLB), diaphragmatic breathing (DB), combination breathing (CB) and respiration muscle endurance training (RMET)] in both standing and sitting positions. %MVIC of them (the multifidus (MF), erector spinae (ES), internal oblique/transversus abdominis (IO/TrA), external oblique (EO), rectus abdominis (RA) measured. [Results] IO/TrA, MF and EO showed greater activation in standing than in sitting, while RA and ES showed greater activation in sitting than in standing. RMET induced significantly greater activation of spinal stability muscles then other breathing patterns. %MVIC changes of muscle activities induced by FRM were independent of position with a few exceptions. [Conclusion] The increased respiratory demands of FRM induced greater activation of spinal stability muscles than QB. RMET was found to be the most effective breathing pattern for increasing the activation of the spinal stability muscles.Key words: Spinal stability muscles, Position, Forced respiratory maneuvers     

Effects of walking with a “draw-in maneuver” on the knee adduction moment and hip muscle activity

[Purpose] To investigate the effect of performing a draw-in maneuver (DI) on knee adduction moment (KAM) and hip and trunk muscle activities while walking. [Participants and Methods] We included 30 healthy young adults (21.5 ± 0.6 years, 16 males and 14 females) in this study. We measured the KAM and lever arm while participants walked with either a normal gait or a DI gait. We also performed surface electromyography (EMG) of the hip and trunk muscles (i.e., internal oblique abdominal muscle [IO], external oblique abdominal muscle [EO], multifidus muscle [MF], and gluteus medius muscle [GM]). [Results] The 1st peak of the KAM was significantly lower when walking with a DI gait compared to when walking with a normal gait. The integrated EMG activity of the IO, EO, and GM during the 1st half of the stance phase, and of the IO and EO during the 2nd half of the stance phase was significantly higher during the DI than during normal gait. [Conclusion] Compared with a normal gait, a DI gait leads to a decrease in the 1st peak of the KAM as a result of the shorter lever arm, and an increase in the muscular activity of the GM, IO, and EO.Key words: Draw-in maneuver, Knee adduction moment, Hip abduction muscle activity     

The Effects of Precise Contraction of the Pelvic Floor Muscle Using Visual Feedback on the Stabilization of the Lumbar Region

[Purpose] The purpose of this study is to verify whether precise contraction of the pelvic floor muscle (PFM) using visual feedback actually affects the thickness of abdominal muscles. [Subjects] The subjects were 29 healthy adults in their 20s who consented to participate in this study. [Methods] This study provided visual feedback on PFM using one ultrasound device and identified changes in the transversus abdominis (TRA) using another ultrasound device. Abdominal muscle thicknesses were measured by ultrasound under three conditions (rest, PFM contraction, PFM contraction with visual feedback). [Results] There were no statistically significant differences in the external oblique (EO) and internal oblique (IO) muscles between the measurements taken at rest and during the contraction of the PFM, and between those taken at rest and during the contraction of the PFM with visual feedback. There were significant differences in the TRA. In particular, TRA thickness was highest in the order of PFM contraction, PFM contraction with visual feedback, and rest. [Conclusion] Hollowing with visual feedback is not an efficient stabilization exercise method for the PFM.Key words: Pelvic floor muscle, Visual feedback, Abdominal muscles     

An Analysis of the Thickness of Abdominal Muscles during Forceful Expiration and Pulmonary Function in Teenage Smokers and Nonsmokers

[Purpose] The purpose of this study was to examine the effects of smoking on teenagers'' internal oblique (IO) and transverses abdominis (TrA) expiratory muscles and their pulmonary function. [Subjects] A total of 30 healthy teenagers (15 smokers; 15 nonsmokers) voluntarily participated in the study. [Methods] The subjects were instructed to maintain an upright standing posture with their scapulars against the wall. Measurements were then taken to determine the thickness of their right IO and their right TrA while they were at rest and in a state of forced expiration using a 7.5 MHz linear probe of an ultrasonic imaging system. The measured thickness was converted into the percentage of change in muscle thickness (PCMT) and the relative contribution ratio (RCR) using a calculation formula, and then the data were analyzed. [Results] No significant differences were found between the two groups in the thickness, PCMT, and RCR of both the IO and TrA muscles, while there were significant differences in the forced expiratory volume at one second (FEV1) and the peak expiratory flow (PEF). [Conclusion] This study examined teenage smokers whose duration of smoking was relatively short. The two groups did not show significant differences in the thickness of both the IO and TrA muscles. However, based on the forced expiratory volume at one second (FEV1) and PEF measurements, the smokers showed greater decreases in pulmonary function than the nonsmokers.Key words: Smokers and nonsmokers, Pulmonary function, Abdominal muscles     

Slow Expiration Reduces External Oblique Muscle Activity during Maximum Trunk Flexion

[Purpose] The purpose of this study was to demonstrate the effects of expiration on abdominal muscle activity during maximum trunk flexion. [Subjects] Twenty-one healthy university students (10 men, 11 women) participated in this study. [Methods] Electromyography (EMG) was used to quantify the activity of the right rectus abdominis, external oblique, and internal oblique muscles. The paired t-test was used to examine the significance of differences in the abdominal muscles between maximum trunk flexion with breath holding and slow expiration. [Results] There was a significantly lower EMG activity in the external oblique muscle during maximum trunk flexion with slow expiration. [Conclusion] The results of this study indicate that slow expiration reduces external oblique muscle activity during maximum trunk flexion performed by healthy young subjects.Key words: Expiration, Electromyography, Abdominal muscles     

Effect of evidence-based trunk stability exercises on the thickness of the trunk muscles

[Purpose] This study was conducted to investigate the effect of four spine stability exercises on the thickness of the internal and external oblique abdominal muscles, the transverses abdominis, and the multifidus muscles. [Subjects and Methods] Forty healthy adults were enrolled and randomly allocated to four groups. Ten participants performed bridge exercises (BE) while lying on their back; 10 others performed the same exercises with their right legs up (BERL); another 10 performed the same exercises on their side (SBE); and the remaining 10 performed them in a quadruped position with left arm and right leg lifts (QLARL). The participants performed the exercises three times a week for five weeks. The thicknesses of the muscles before and after the interventions were measured using ultrasound. [Results] The results show that the normal bridge exercise significantly thickened the TrA; BERL, the LM; QLARL, the IO; and SBE, the EO and the IO. [Conclusion] All four spine stability exercises were effective. The normal bridge exercise and BERL selectively strengthened the local muscles at the early stage of the treatment. We consider SBE and QLARL should be used in the later stages of treatments because they strengthen both the local and global muscles.Key words: Trunk muscle thickness, Trunk stabilization, Ultrasonograpy     

Ultrasound measurement of abdominal muscles during clinical isometric endurance tests in women with and without low back pain

Purpose: The present study investigated group differences between the thickness changes of the transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) muscles, during performance of the isometric supine chest raise and the supine double leg-straight leg raise tests in women with and without low back pain (LBP). Method: Twenty women with LBP and 20 women without LBP participated in this case-control study. The thickness of the right TrA, IO, and EO muscles was measured using B-mode ultrasound (US) at rest, immediately at the beginning of performing the tests and when participants in both groups self-reported fatigue. The percentage of change in thickness of the abdominal muscles from rest to the initiation and fatigue stages of both tests was measured. Results: The results indicate a statistically significant difference in the pattern of changes in deep (TrA) and superficial (EO) abdominal muscles thickness at the fatigue stage of the supine double straight-leg raise (SDSLR) test between groups (P < 0.05). There was no significant difference between groups for the abdominal muscles thicknesses change at rest or during stages of the clinical isometric endurance tests (P > 0.05). Conclusions: An altered activation pattern in the deep (TrA) and superficial (EO) muscles of LBP participants during fatigue stage of the SDSLR test as compared to controls indicates motor control dysfunction in the LBP group. Comparison of the activity of TrA and EO muscles during fatigue stage of SDSLR test can be used to assess alterations in motor control of abdominal muscles.     

A Comparison of Vaginal Pressures and Abdominal Muscle Thickness According to Childbirth Delivery Method during the Valsalva Maneuver

[Purpose] The purpose of this study was to compare the effect of childbirth delivery method on vaginal pressure and abdominal thickness during the Valsalva maneuver (VAL). [Subjects] Thirty healthy female volunteers (26–39 years of age) were selected for this research. Their delivery histories were: nulliparous 10, vaginal delivery 10, and Cesarean delivery 10. None of the participants had a history of incontinence. [Methods] In the crook-lying position, a perineometer probe was inserted into the vagina and the transducer was placed transversely on the right side of the body during the Valsalva maneuver. [Results] There were significant differences in the thickness of the transverses abdominis (TrA) between in all the groups rest and the Valsalva maneuver, and there were significant differences in the internus oblique (IO) in the nulliparous group. During the Valsalva maneuver, there were significant differences in the TrA between the nulliparous group and the vaginal delivery group, and there were significant differences in the IO between the nulliparous delivery group and the vaginal delivery group, and between the nulliparous group and the Cesarean section group. Delivery history changed vaginal pressure, and there were significant differences between the nulliparous group and the vaginal delivery group, and between the nulliparous group and the Cesarean delivery group. [Conclusion] Pregnancy and delivery method may affect pelvic floor and abdominal muscles during the Valsalva maneuver.Key words: Ultrasound image, Valsalva maneuver, Vaginal pressure     

The effects of bridge exercise with the abdominal drawing-in maneuver on an unstable surface on the abdominal muscle thickness of healthy adults

[Purpose] The purpose of this study was to determine the impact of a bridge exercise with an abdominal drawing-in maneuver (ADIM) performed with different surface conditions on abdominal muscle thickness. [Subjects] Thirty subjects were randomly divided into an unstable bridge exercise group (UBE group, n=15) and a stable bridge exercise group (SBE group, n=15). [Methods] After 6 weeks of performing bridge exercises accompanied by ADIM, the change in the muscle thicknesses of the transverse abdominis (TrA) and internal oblique abdominis (IOA) muscles was assessed using ultrasonography. [Results] After 6 weeks of exercise, the TrA was significantly altered in the SBEG, and the TrA and IOA were both significantly changed in the UBEG. [Conclusion] When performing bridge exercises to increase the Tra and the IO muscle thicknesses, exercising on an unstable surface is recommended.Key words: Transversus abdominis, Bridge exercise, Abdominal drawing-in maneuver