Lower Rectus Abdominis Research Articles

Electromyographic comparison of the upper and lower rectus abdominis during abdominal exercises.

The objective of this pilot study was to determine the effect of 6 different abdominal exercises on the electrical activity of the upper rectus abdominis (URA) and lower rectus abdominis (LRA). Eight healthy, adult volunteers completed 6 random abdominal exercises: curl up, Sissel ball curl up, Ab Trainer curl up, leg lowering, Sissel ball roll out, and reverse curl up. Action potentials were recorded and analyzed from the URA and the LRA using surface electromyography (EMG) during a 2-second concentric contraction. The average normalized data were compared between the URA and the LRA in order to determine the behavior of the different muscle sites and between exercises in order to determine which exercises elicited the highest EMG activity. There were no significant differences (p > 0.05) between the EMG activity of the URA and LRA during any exercise. There were no significant interactions between subject and muscle site or between exercise and muscle site. Significant differences were found among the 6 exercises performed, and due to the interaction between subject and exercise performed. Both the URA and the LRA recorded significantly higher mean amplitudes during the Sissel ball curl up than during all other exercises. In addition, the curl up, Sissel ball curl up, and Ab Trainer curl up had significantly higher normalized EMG activity in both muscle sites than the reverse curl up, the leg lowering exercise, and the Sissel ball roll out. The curl up and the Ab Trainer curl up exercises were not significantly different in terms of their normalized EMG activities for both the URA and the LRA.

Venous interruption is unnecessary to achieve an adequate delay in the rat TRAM flap model.

Staged division of any or all inferior dominant pedicles to the human lower transverse rectus abdominis musculocutaneous (TRAM) flap has previously been attempted to invoke the delay phenomenon to enhance the rate of success with the superior-pedicled version, especially for patients at high risk for complications. Regardless of the specific vessels ligated, this has usually been accomplished by division of the source artery and its accompanying vein. Whether division of both vessels is essential remains unclear, however. This issue was investigated by using the authors' standard rat TRAM flap model in 43 female Sprague-Dawley rats, which were randomly assigned to four groups. In group A, both the predominant ipsilateral cranial epigastric artery and the cranial epigastric vein were divided 2 weeks before elevation of the TRAM flap. In group B, only the artery was divided; in group C, only the vein was divided. In an undelayed control group, the TRAM flap was elevated immediately, with no prior pedicle division. The percentages of flap survival in group A (89.3 +/- 7.0 percent) and group B (88.8 +/- 6.5 percent) (both with division of the predominant artery) were significantly greater than that in the control group (64.6 +/- 20.5 percent) (p < 0.001) or that in the group in which the vein alone was divided (73.9 +/- 11.3 percent) (p < 0.01). There was no significant difference between the group that underwent vein division only and the control group (p = 0.102). The clinical implication is that arterial division is critical for TRAM flap delay and that arbitrary venous interruption is unnecessary.

Relative Activity of Abdominal Muscles During Commonly Prescribed Strengthening Exercises

The purpose of this study was to determine the relative electromyographic (EMG) activity of the upper and lower rectus abdominis and the external oblique muscles during 5 commonly performed abdominal strengthening exercises. Twenty-five healthy subjects participated in the study. EMG data were collected under isometric and dynamic conditions. The reverse curl resulted in the greatest amount of lower rectus activity, the v-sit and reverse curl exercises resulted in the greatest amount of external oblique activity, and the trunk curl, reverse curl, trunk curl with a twist, and v-sit all resulted in similar amounts of upper rectus EMG activity. The vacuum exercise resulted in moderate levels of external oblique EMG activity but very low levels of activity in the rectus abdominis. Our findings support the concept that abdominal strengthening exercises can differentially activate various abdominal muscle groups, but contradict some traditionally held assumptions regarding the effects of pecific exercises.

Relative Activity of Abdominal Muscles During Commonly Prescribed Strengthening Exercises

The purpose of this study was to determine the relative electromyographic (EMG) activity of the upper and lower rectus abdominis and the external oblique muscles during 5 commonly performed abdominal strengthening exercises. Twenty-five healthy subjects participated in the study. EMG data were collected under isometric and dynamic conditions. The reverse curl resulted in the greatest amount of lower rectus activity, the v-sit and reverse curl exercises resulted in the greatest amount of external oblique activity, and the trunk curl, reverse curl, trunk curl with a twist, and v-sit all resulted in similar amounts of upper rectus EMG activity. The vacuum exercise resulted in moderate levels of external oblique EMG activity but very low levels of activity in the rectus abdominis. Our findings support the concept that abdominal strengthening exercises can differentially activate various abdominal muscle groups, but contradict some traditionally held assumptions regarding the effects of specific exercises.

Muscle activity in upper and lower rectus abdominus during abdominal exercises

Objective: To compare the intensity of the upper versus lower rectus abdominis (RA) muscle activity provoked by each of two different abdominal exercises and to contrast the intensity of contraction elicited by two different abdominal exercises on each RA muscle portion. Design: Nonrandomized control trial. Setting: Kinesiology laboratory in a university medicine faculty. Participants: Convenience sample of 33 healthy volunteers. Subjects who had practiced endurance or strength training activities (1.5 hours 3 days a week for 3 years) and those who had not accomplished that criterion comprised a high and a low physical activity group, respectively. Each of these two groups was divided by the ability to perform the exercises into two subgroups: correct and incorrect performers (cp, ic). Main Outcome Measure: Average surface iEMG was compared between upper and lower RA and on each muscle portion performing curl-up (CU) and posterior pelvic tilt (PT) exercises. The coefficient of variation, a two-way analysis of variance, and the t test were calculated. Results: The upper RA showed significantly greater activity during performance of CU exercise by the cp subgroups of both high (t = 2.14302, 95%) and low (t = 2.35875, 95%) activity groups. Only the cp subgroup of the high activity group showed that PT was significantly more strenuous than CU exercise on lower RA (t = -2.06467, 95%). Conclusions: Among correct performers, CU produces greater activity on upper RA. For persons who have a high level of activity, PT is more strenuous than CU on lower RA. Among incorrect performers, either exercise indistinctly activates the muscle portions.

An electromyographic validation of an abdominal muscle test

A recently developed abdominal muscle test (AMT), using four levels of difficulty to assess abdominal muscle strength, was validated by examination of the functional interrelationship between the individual muscles during the AMT, and by determining the relationship between the AMT level of difficulty and electromyographical (EMG) activity. EMG data were collected from the upper and lower rectus abdominis, and the external and internal oblique in 22 subjects as they participated in the AMT. Typically, throughout the AMT, lower rectus abdominis was most active, followed by upper rectus abdominis, external oblique, and internal oblique. EMG activity increased significantly (p < .05) for all muscles from Levels 1 to 3. At Level 4, although upper and lower rectus abdominis remained more active than the obliques, the relative contribution from the obliques was increased. The results of this study show that the AMT is a valid indicator of ability to develop voluntary abdominal muscle tension in Levels 1 to 3, although, Level 4 is more indicative of the oblique muscles' functional abilities and therefore may be considered a distinctly different muscle test.

Effect of a Lumbar Support Device on Muscle Activity During Abdominal Exercise

The purpose of this study was to investigate abdominal, hip flexor, and low back muscle activation during six abdominal exercises performed both with and without a lumbar support device. Myoelectric activity was monitored with surface electrodes over the upper and lower rectus abdominis, rectus femoris, and the L3 level of erector spinae as 32 male subjects performed the six exercises recommended in the product instruction manual both with and without the product. Significant (p < 0.0125) differences in myoelectric activity were found across some but not all levels of exercise difficulty, but no difference was found at any of the four muscle sites between exercises performed with as compared to without the lumbar support device. These findings contradict the notion that a lumbar support device isolates the abdominal muscles during abdominal exercise performance.

Techniques for active lumbar stabilisation for spinal protection: A pilot study

Active protection of the lumbar spine is important in prevention of back strain during exercise. This EMG study investigated three common techniques used for lumbar stabilisation : posterior pelvic tilt, lower abdominal hollowing with lumbar spine flattening and abdominal bracing. The aim was to determine which method encouraged the best stability pattern. Muscle activity was measured in obliquus abdominis, upper and lower rectus abdominis and the lumbar erector spinae. Standardisation of muscle activity against that during maximally resisted trunk rotation (already shown to illustrate an appropriate stability pattern) allowed comparisons between exercise techniques in relation to their stabilisation pattern. Results indicated that posterior pelvic tilt demonstrated the least desirable stability pattern. Both abdominal hollowing and bracing provided a more suitable pattern.

An initial evaluation of eight abdominal exercises for their ability to provide stabilisation for the lumbar spine

Eight abdominal strengthening exercises were investigated in order to evaluate their ability to promote stabilisation of the lumbar spine. Twenty-three healthy volunteers aged between 18 and 32 participated in the study. During each of the selected exercises, surface electromyography was used to measure the level of motor unit activity in the right upper rectus abdominis, the right lower rectus abdominis, the right oblique abdominis and right lumbar para-vertebral muscles. A formula, based on the relative importance of each muscle in the proposed stability pattern was devised and used to give a single 'stability' score in order to compare each of the eight exercises tested. Results indicated that the exercises which involved applied rotatory resistance to the trunk appeared to activate a more appropriate stability pattern for the lumbar spine.

Polyglactin 910 Mesh for Support of the Donor Defect of the Double-pedicled Rectus Abdominis Musculocutaneous Flap

The most significant concern in using the lower rectus abdominis musculocutaneous flap is creation of an eventration or even a frank hernia of the abdominal wall. Frequently, reinforcement using an alloplastic implant following closure of the double-pedicled donor defect is required. In an effort to avoid the use of any foreign materials, particularly if the goal in breast reconstruction is to use only autogenous tissues, strong consideration for incorporating an absorbable mesh is advocated to provide abdominal wall support.

The use of the lower rectus abdominis musculocutaneous flap in breast reconstruction

The use of the lower rectus abdominis musculocutaneous flap in breast reconstruction

Rectus abdominis myocutaneous flap of the lower type in breast reconstruction.

A lower rectus abdominis myocutaneous flap has been used in thirteen cases; in twelve patients for breast reconstruction with delay after mammectomy, and in one patient to close a defect due to an extensive mammectomy for cancer recurrence. In our opinion, the main advantages of the lower rectus abdominis myocutaneous flap are the very natural shape and the firmness of the reconstructed breast. The color and thickness of the abdominal skin is also quite similar to that of the chest. The low design of the cutaneous island, as in an abdominoplasty, gives an excellent cosmetic result. There is also enough skin and fat to make a breast implant unnecessary. In corpulent women the ends of the flap have to be resected to avoid partial necrosis. In slim women, the entire cutaneous island can be used. In all cases, repair of the musculo-aponeurotic wall has been performed without any prosthetic material. No foreign material has been used in this reconstruction. No eventration was observed in our patients.

Treatment of thoracic radionecrosis with lower rectus musculocutaneous flaps

In three patients lower transverse rectus abdominis (TRAM) musculocutaneous flaps have been used to cover lesions following radiotherapy. Only one flap healed without complications. The other two developed partial fat necrosis followed by infection and the formation of either an abcess or a fistula; both complications eventually healed.

Experience with the transverse lower rectus abdominis operation for breast reconstruction.

Our initial experience with the lower rectus abdominis procedure for breast reconstruction in 19 patients is presented. Anatomic considerations, surgical technique, and results are reviewed. Errors in flap design and execution resulted in a disproportionately high complication rate, which improved following certain technical refinements. The lower rectus flap has proved to be an alternative to conventional techniques of breast reconstruction. As more experience is gained with this flap, its particular role in the reconstructive armamentarium will be more clearly defined.

The use of myocutaneous flaps in block dissections of the groin in cases with gross skin involvement

Various myocutaneous flaps (upper sartorius, upper gracilis and lower rectus abdominis) have been used in a series of 17 block dissections of the groin with gross skin involvement. Only one of these flaps developed appreciable necrosis. The sartorius flap is restricted in its application for anatomical reasons. The rectus abdominis flap can only be used from the opposite side in unilateral cases, though it does appear to be the most dependable flap. The gracilis flap appears to be the most suitable for the majority of the patients who usually present with bilateral involvement of the lymph nodes and skin.

An Electromyographic Investigation of the Rectus Abdominis in Abdominal Exercises

Abstract The upper and lower rectus abdominis (RA) were studied electromyographically through a series of 10 strenuous abdominal exercises and a trunk flexion isometric strength test. Intensity of contraction was greatest in the basket hang, followed by three variations of the hook sit-up. The curl-up and the inclined, arched back and conventional sit-ups came next in intensity, while the V-sit and controlled backward lean were the least strenuous exercises tested. In the upper RA several of the exercises elicited greater MAPs than were elicited by the maximal isometric effort involved in the trunk flexion test. The apparently strenuous nature of the basket hang, which is primarily a movement of thigh rather than trunk flexion, implies that this exercise may be useful in the abdominal training of highly conditioned athletes.