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Concept: Abdominal external oblique muscle


Training the bench press exercise on a traditional flat bench does not induce a level of instability as seen in sport movements and activities of daily living. Twenty participants were recruited to test two forms of instability: using one dumbbell rather than two and lifting on the COR bench compared to a flat bench. Electromyography (EMG) amplitudes of the pectoralis major, middle trapezius, external oblique, and internal oblique were recorded and compared. Differences in range of motion (ROM) were evaluated by measuring an angular representation of the shoulder complex. Four separate conditions of unilateral bench press were tested while lifting on a: flat bench with one dumbbell, flat bench with two dumbbells, COR Bench with one dumbbell, and COR Bench with two dumbbells. The results imply that there are no differences in EMG amplitude or ROM between the COR bench and traditional bench. However, greater ROM was found to be utilized in the single dumbbell condition, both in the COR bench and the flat bench.

Concepts: Fundamental physics concepts, Muscle, Electromyography, Bench press, Abdominal external oblique muscle, Pectoralis major muscle, Clavicle, Barbell


[Purpose] It has been reported that exercises focusing upon the transversus abdominis (TrA) ameliorate low back pain (LBP). We investigated whether expiratory muscle training (EMT) can promote activity of the TrA to the same degree as the abdominal drawing-in manoeuvre (ADIM) in elderly individuals. [Subjects and Methods] Twenty-one elderly subjects (9 males, 12 females; mean age, 84.9 ± 6.6 years) without LBP symptoms were included. Using ultrasound imaging we measured changes in thickness of the lateral abdominal muscles, TrA, internal oblique muscle (IO), and external oblique muscle (EO) during ADIM and EMT. The load in EMT was set to 15% of maximal expiratory pressure. [Results] TrA showed a significant increase in muscle thickness during ADIM and EMT compared with at rest. A significant increase in muscle thickness was noted for EMT in comparison with ADIM. No significant differences were found for IO and EO. [Conclusion] In elderly people, EMT may be an effective alternative to ADIM for promoting activity of the TrA and can be used as an exercise to maintain TrA function.

Concepts: Physical exercise, Transversus abdominis muscle, Abdomen, Iliac crest, Abdominal external oblique muscle, Muscles of the torso, Iliohypogastric nerve, Abdominal internal oblique muscle


This study reports the case of a patient with a severely resorbed mandible who was treated without a bone graft, using short implants, internal rigid fixation, rhBMP-2 and β-tricalcium phosphate. A 76-year-old woman, with a severely resorbed mandible (less than 3mm), reported a history of nearly 25years of complete edentulism and consecutive treatment failures, with total bilateral exposed inferior alveolar nerves and complete bone resorption of the inferior border in some areas. The treatment of choice was the placement of a 2.0mm thick unilock bone plate (MatrixMandible, Synthes Maxillofacial, Paoli, PA, USA), to reinforce the mandible. Eight short implants with a regular platform (Nobel Biocare, Goteborg, Sweden) were placed: three on the external oblique line on both sides and two on the symphysis. In order to augment mandible height and coat the exposed thread of the anterior implants, rhBMP-2 (Infuse Bone, Meditronic Sofamor Danek, Memphis, TN, USA) and β-tricalcium phosphate (Cerasorb; Curasan, Kleinostheim, Germany) were used. Four 1.3mmL miniplates were placed to support the graft. 14months after surgery, the patient was satisfied and had excellent function without complications.

Concepts: Bone, Surgery, Bone resorption, Sweden, Dental implant, Oral and maxillofacial surgery, Abdominal external oblique muscle, Nobel Biocare


BACKGROUND:: Slipping rib syndrome (SRS) is a musculoskeletal cause of severe and recurrent thoracic or abdominal pain. The etiology of SRS is unknown, it seems to arise from costal hypermobility with a tendency of one of the ribs (usually from 8th to 10th but also 11th and 12th have been described) to slip under the superior adjacent rib. Its prevalence is underestimated because SRS is mainly a clinical diagnosis, frequently missed. The critical aspect of the diagnosis is knowledge of the condition itself, which, when lacking, often results in the patient being referred to many different specialists and exposed to unnecessary and costly investigations. The management of the condition includes conservative techniques such as manipulation, localized anesthetic, and steroid or anesthetic nerve block. However, where conservative therapy fails, surgical treatment, with excision of the rib, may be performed. METHODS:: In this paper we describe the case of a patient with persistent and debilitating flank pain who, after many investigations, was diagnosed with SRS. RESULTS:: The usual conservative treatment failed, after which we treated the patient with injections of incobotulinumtoxin A into muscles inserting on the inferior side of the rib cage (quadratus lumborum muscle, muscle transversus abdomini, abdominal external oblique muscle, and recto abdomini) achieving a complete relief from pain. CONCLUSIONS:: To our knowledge botulinum toxin has never been proposed before for the treatment of SRS. We believe that it should be considered as a therapeutic option, especially where other medical treatments have failed or as an intermediate step before surgical intervention.

Concepts: Abdomen, Thorax, Rib, Human rib cage, Iliac crest, Abdominal external oblique muscle, Muscles of the torso, Quadratus lumborum muscle


Background: Sport climbing has been increasingly applied as therapy for patients with orthopaedic problems. Results from previous intervention studies have already revealed positive effects, especially for people with back problems, although there is a lack of baseline knowledge regarding the general effects of climbing. The aim of this present study is to investigate the muscle activation of the trunk while performing various static climbing positions at different inclination angles. Subjects/Material and Methods: Thirteen healthy adults without climbing experience were asked to hold three static climbing positions (base position, lifting a hand, lifting a foot) at three different handhold set-ups and six wall inclination angles (0°, 4°, 8°, 12°, 15°, 18°) for 5 seconds each. Bilateral muscle activity of Erector spinae, Multifidus, Latissimus dorsi, Obliquus externus abdominis, Obliquus internus abdominis and Rectus abdominis was measured using surface electromyography. Data were analysed for each muscle and climbing condition separately. Results: Compared to the vertical wall, the muscle activity starts to differ significantly (p ≤ 0.05) from 12° onwards. This inclination angle particularly affects the activity of all muscles when lifting a hand (0.000 ≤ p ≤ 0.048). The oblique abdominal muscles did not show any or little effects when lifting a foot or being in the base position, while all other muscles demonstrate a continuous increase. The EMG data were normalised to the corresponding base position and analysed for each muscle and climbing condition separately. Conclusion: Inclinable climbing walls are an appropriate method to increase muscle activity. Compared to the base position, activation of the oblique abdominal muscles, which are relevant for a stable trunk, is increased only when a hand is lifted. Climbing walls used for therapy should offer variable inclination angles. Further research should concentrate on the development and evaluation of climbing exercises for specific patients (eg people with scoliosis).

Concepts: Muscle, Electromyography, Abdomen, Iliac crest, Abdominal external oblique muscle, Muscles of the torso, Crunch, Abdominal internal oblique muscle


To examine the effects of grunting on velocity and force production during dynamic and static tennis strokes in collegiate tennis players. Thirty-two (16 M and 16 F) Division II and III collegiate tennis athletes with a mean age of 20.2 ± 1.89 years participated as subjects. Demographic and survey data were obtained prior to subjects completing a 10-15 minute warm-up of serves and ground strokes while grunting and not grunting. Subjects performed randomized sets (3 grunting and 3 non-grunting trials) of serves and forehand strokes both dynamically and isometrically. Stroke velocities and isometric forces were measured with a calibrated radar gun and calibrated dynamometer, respectively. EMG data from subjects' dominant pectoralis major and contralateral external oblique muscles were recorded and averaged for data analysis. A repeated measures multivariate analysis of variance (RM-MANOVA) compared dynamic stroke velocity, isometric muscle force, and peak EMG activity during each breathing condition at the 0.05 alpha level. The RMANOVA indicated that dynamic velocity and isometric force of both serves and forehand strokes were significantly greater when subjects grunted (F=46.572, p<0.001, power=1.00). Peak muscle activity in the external oblique and pectoralis major muscles was also greater when grunting during both types of strokes (F=3.867, p=0.05, power=0.950). Grunt history, gender, perceived advantages and disadvantages of grunting, years of experience, highest level of competition, and order of testing did not significantly alter any of these results. The velocity, force, and peak muscle activity during tennis serves and forehand strokes are significantly enhanced when athletes are allowed to grunt.

Concepts: Energy, Torque, Mass, Electromyography, Analysis of variance, Velocity, Abdominal external oblique muscle, Pectoralis major muscle


To examine the effects of forced expiration (FE), forced inspiration (FI), grunting (GR), and Valsalva maneuver (VM), on air volume, maximum force production, and muscle recruitment during a simulated forehand stroke in collegiate tennis players. Superficial electrodes were placed over the anterior deltoid, pectoralis major, rectus abdominus, lumbar and thoracic erector spinae, external and internal obliques. Subjects stood in a simulated forehand stroke stance with their dominant hand positioned on a force plate. Subjects performed three repetitions of maximal 2-3-sec isometric forehands with randomly assigned breathing conditions (FE, FI, VM, GR) and 30-seconds rest between contractions. Air volumes were also collected during each trial. A repeated measures MANOVA compared normalized peak EMG activity across the seven muscle groups. Separate repeated measures ANOVAs compared the effect of breathing conditions on peak force production and air volume. Statistical significance was set at p ≤ 0.05 for all analyses. Overall muscle activity differed significantly by breathing condition (p=.031) with greater anterior deltoid activity was seen in FE and GR vs. VM. Internal oblique activity was significantly greater in GR than FI or VM, and thoracic erector spinae activity was significantly greater during FE and VM than FI. Force production did not differ significantly among breathing conditions (p=0.74); however, GR forces were greater than FI and VM forces (p<.05). FE air volume was significantly greater (p<.001) than FI, GR or VM. These findings suggest that either GR or a more quiescent FE can be used to enhance force production. FE is a potentially safer alternative to VM and more aurally pleasing than GR.

Concepts: Energy, Torque, Integral, Force, Electromyography, Abdominal external oblique muscle, Clavicle, Forehand


The abdominal wall is a prime target for therapeutic exercises aimed to prevent and rehabilitate low back pain as well as enhance performance training. This study examined the “Lewit”; a corrective exercise prescribed for several purposes, which is performed lying supine in a crook-lying position and involves forceful breathing. Muscle activation and lumbar posture was compared with bracing the abdominal wall (stiffening) with robust effort and “hollowing” (attempting to draw in the wall towards the naval) with robust effort. Eight healthy male volunteers with six channels of electromyography (EMG) were collected via surface electrode pairs of rectus abdominis, external oblique and internal oblique together with lumbar motion. The Lewit exercise caused higher muscle activity in the deeper abdominal wall muscles, in particular internal oblique and by default transverse abdominis were activated at 54% MVC on average and 84% MVC peak with no change in spine posture to maintain elastic equilibrium of the lumbar spine. The Lewit is a deep oblique muscle activation exercise and the activation levels are of sufficient magnitude for training muscle engrams. This information will assist strength and conditioning coaches with program design decisions where this corrective abdominal exercise may be considered for clients who elevate the ribcage during strength exertions, or for clients targeting the deep obliques.

Concepts: Spinal disc herniation, Muscle, Physical exercise, Electromyography, David Gilmour, Iliac crest, Abdominal external oblique muscle, Muscles of the torso


ABSTRACT Social, psychological, and physiological studies have provided evidence indicating that laughter imposes an increased demand on trunk muscles. It was the aim of this study to quantify the activation of trunk muscles during laughter yoga in comparison with crunch and back lifting exercises regarding the mean trunk muscle activity. Muscular activity during laughter yoga exercises was measured by surface electromyography of 5 trunk muscles. The activation level of internal oblique muscle during laughter yoga is higher compared to the traditional exercises. The multifidus, erector spinae, and rectus abdominis muscles were nearly half activated during laughter yoga, while the activation of the external oblique muscle was comparable with the crunch and back lifting exercises. Our results indicate that laughter yoga has a positive effect on trunk muscle activation. Thus, laughter seems to be a good activator of trunk muscles, but further research is required whether laughter yoga is a good exercise to improve neuromuscular recruitment patterns for spine stability.

Concepts: Muscle, Physical exercise, Electromyography, Exercise physiology, Iliac crest, Abdominal external oblique muscle, Muscles of the torso, Crunch


[Purpose] The purpose of this study was to examine the effect of lumbar stability exercises on chronic low back pain by using sling exercise and push-ups. [Subjects] Thirty adult subjects with chronic back pain participated, with 10 adults being assigned to each of 3 exercise groups: general physical therapy (PT), lumbar stability using sling exercises (Sling Ex), and sling exercise plus push-ups (Sling Ex+PU). Each group trained for 30 minutes 3 times a week for 6 weeks. The Oswestry Disability Index (ODI), surface electromyographic (sEMG) activity of the lumbar muscles, and cross-sectional area of the multifidus muscle on computed tomography (CT) were evaluated before and at 2, 4, and 6 weeks of therapy. [Results] A significant decrease in ODI was seen in all therapy groups, and this change was greater in the Sling Ex and Sling Ex+PU groups than in the PT group. No changes in sEMG activity were noted in the PT group, whereas significant increases in the sEMG activities of all lumbar muscles were found in the other 2 groups. The increases in the sEMG activities of the rectus abdominis and internal and external oblique muscles of the abdomen were greater in the Sling Ex+PU group than in the other 2 groups. [Conclusion] These findings demonstrate that Sling Ex+PU, similar to normal lumbar stabilization exercise, is effective in activating and improving the function of the lumbar muscles. These results suggest that Sling Ex+PU has a positive impact on stabilization of the lumbar region.

Concepts: Spinal disc herniation, Low back pain, Back pain, Muscle, Physical exercise, Massage, Abdominal external oblique muscle, Lumbar