Lower Rectus Abdominis Research Articles

Electromyographic Comparison of an Abdominal Rise on a Ball with a Traditional Crunch.

We propose a new exercise, the abdominal rise on the ball, to replace the traditional crunch in exercise programs. The aim of this study is to compare the activity of the abdominal muscles when performing an ARB with the same activity when performing a traditional crunch. Twenty healthy adults participated in the study. Surface electromyography (EMG) was recorded from the upper and lower rectus abdominis (URA, LRA), internal oblique (IO), external oblique (EO), transversus abdominis (TrA), and erector spinae (ES). EMG values were normalized to maximal voluntary isometric contraction. A paired t-test, nonparametric Wilcoxon test and correlation coefficient were used for statistical analysis. The normalized EMG values of EO, TrA and ES, were statistically significantly higher during the abdominal rise on the ball compared to the traditional crunch, while URA, LRA and IO were significantly lower during the abdominal rise on the ball compared to the traditional crunch. TrA, EO and IO are sufficiently activated during an abdominal rise on a ball, so the exercise could be deemed effective for strengthening these muscles.

The effects of togu-jumper use on core muscle activity during plank exercise

Purpose This study was to analyze and compare series of muscle activities during plank exercises with use of togu-jumper. Methods Ten male subjects (age 26.9±1.7 yrs, height 172.2±5.7 cm, weight 66.5±7.5 kg) who have no musculoskeletal disorder with one's upper or lower limb were selected as subjects. To analyze and compare series of muscle activity, five of surface EMG electrodes were attached to the upper rectus abdominis (URA), lower rectus abdominis (LRA), external abdominal oblique (EO), erector spinae (ES) and gluteus maximus (GM). Each subject did plank exercise on stable support surfaces (normal surfaces) and unstable support surfaces with the togu-jumper. For each dependent variable, one-way ANOVA with repeated measures were performed with significance level p<.05. Contrasts were performed to execute post tests for results with statistical significance. Results The study showed that the average IEMG values of URA and LRA increased in Upper (Togu-jumper used upper limb) compared to normal surfaces. This is perhaps because the effects of URA more than any other muscles for body stability. Furthermore, the peak IEMG values of LRA increased in Upper and Lower (Togu-jumper used lower limb) compared to normal surfaces. In addition, peak IEMG values of EO increased in Upper compared to Normal. This may have resulted due to momentary strong muscle activity in LRA and EO to correct body posture and balance. Therefore, using Togu-jumper on upper limb maximizes the performance of core training in plank exercise. Conclusions The study may be further applied to a method for effective training. It is considered that research and analysis has to be further done on modified plank exercise. Additionally, it is necessary to analyze not only global muscle but also local muscle, as a comprehensive research, to suggest ideal method for plank exercise.

Rectus abdominis activity, but not femoris, is similar in different core training exercises: A statistical parametric mapping analysis

Rectus abdominis (RA) and rectus femoris (RF) differently activate in hip and trunk flexion movements. Previous studies using surface electromyography (sEMG) showed heterogenous results in mean and maximum activity of Upper (URA), Middle (MRA), and Lower (LRA) RA. Statistical Parametric Mapping (SPM) and Time-Varying Multi-muscle Co-activation function (TMCf) are emerging methods for whole-time-course continuous comparisons of muscle activity and co-activation. The aim was to analyse RA and RF activity in three core training exercises with continuous approach. Eight subjects performed Curl-up, Sit-up 45° and Sit-up 90° (where 45° is half and 90° is complete trunk flexion). sEMG from URA, MRA, LRA and RF were normalized to the maximum voluntary contraction root-mean-square (RMSMVC), and compared among muscles/exercises with SPM and TMCf. Angular displacement was assessed using stereophotogrammetry. Curl-up, Sit-up 45° and Sit-up 90° did not differently activate URA, MRA or LRA, and in their common range of motion (ROM) RA activity was similar among the three exercises. Conversely, Sit-up exercises elicited higher RF activity than Curl-up (on average 45% vs. 25% RMSMVC) mainly due to the wider ROM. RA-RF co-activation pattern was different in concentric and eccentric phases between Sit-up exercises and Curl-up, leading to significantly higher co-activation in Sit-up exercises.

Electromyographic Effect of Using Different Attentional Foci During the Front Plank Exercise.

The aim of this cross-sectional study was to examine whether an internal focus on different core muscles during the isometric prone plank exercise increased muscle activity. Twenty university students performed the following five different conditions: regular prone plank (external focus) and prone plank with an internal focus on different muscles. Surface electromyography signals were recorded for the upper rectus abdominis, lower rectus abdominis, external oblique, and lumbar erector spinae. For the upper rectus abdominis, an internal focus on using any muscle increased activity. For the lower rectus abdominis, internal focus on any muscle except the lumbar erector spinae increased activity. No changes were found for external oblique and lumbar erector spinae activity. Upper rectus abdominis and lower rectus abdominis activities increased during an internal focus on the abdominal muscles. external oblique and lumbar erector spinae activities were nonaffected by an internal focus on any muscle.

Análise eletromiográfica de músculos do abdome e reto femoral em exercícios abdominais com e sem superfície instável

Os exercícios abdominais são realizados visando a prevenção e/ou reabilitação de dores na região lombar, a melhoria do rendimento atlético, aumento da resistência e força do tronco durante o desempenho das atividades da vida diária e pela estética. Objetivou-se analisar e comparar a atividade eletromiográfica dos músculos rectus abdominis parte superior (RAS) e parte inferior (RAI), obliquus externus abdominis (OE), obliquus internus abdominis (OI) e rectus femoris (RF) durante o exercício abdominal tradicional com e sem a utilização do bosu e bola de ginástica. A amostra foi composta por dez voluntários do gênero masculino, fisicamente ativos e sem distúrbio neuromuscular. A coleta de dados foi realizada utilizando-se eletrodos de superfície diferenciais simples, com ganho de 20 vezes, e registrada por meio de um eletromiógrafo computadorizado. O sinal eletromiográfico foi quantificado pela Raiz Quadrada da Média (Root Mean Square [RMS]) e normalizado (RMSn) pela Contração Isométrica Voluntária Máxima. Os dados foram submetidos à análise estatística paramétrica, empregando-se teste de análise de variância de medidas repetidas (Anova). Os resultados demonstraram que atividade do músculo RAS no exercício com bosu foi significativamente maior em relação ao tradicional (p < 0.05), todavia, não foram encontradas diferenças significativas (p > 0.05) para músculos RAI, OE, OI e RF, entre todos exercícios abdominais (tradicional, bosu e bola de ginástica). Conclui-se que a utilização do bosu no exercício abdominal pode ser um fator desejável e necessário em estágios específicos de programas de reabilitação e/ou treinamento físico, principalmente quando objetiva-se aumentar o recrutamento da parte superior do músculo rectus abdominis (RAS).

Zhu's trocar placement in laparoscopic appendectomy in the treatment of complicated appendicitis

To evaluate the feasibility and efficacy of Zhu's trocar placement (ZTP) in laparoscopic appendectomy (LA) in the treatment of complicated appendicitis. Clinical data of 139 complicated appendicitis patients undergoing LA at the First Affiliated Hospital of Wenzhou Medical University from June 2013 to December 2017 were retrospectively analyzed. ZTP-LA group comprised 59 cases and its procedure was as follows: 10 mm umbilical trocar was used as lens port; 12 mm trocar at crossing point of umbilical hole horizontal line and right midclavicular line was used as main operating port; 5 mm trocar at the crossing point of horizontal line 0-3 cm below umbilicus and right anterior axillary line was used as assist operating port with the drainage function for Douglas fossa and right iliac fossa; The operator and the assistant stood on the right side and the left side of the patient respectively. Traditional three-port group comprised 80 cases (8 cases converted to laparotomy, 72 cases enrolled finally) and its procedure was as follows: 10 mm lens port below umbilicus; 10-12 mm main operating port at lateral border of left lower rectus abdominis; 5 mm assist operating port above pubis; The operator and the assistant stood on left side of the patient. The operative time, time to oral semi-fluid, postoperative hospital stay, cost during hospitalization, and postoperative morbidity of complication were compared between two groups. Baseline data such as gender, age, WBC count, percentage of leukocyte, pathological finding and type were not significantly different between two groups(all P>0.05). The conversion rate in ZTP-LA was significantly lower than that in traditional three-port group [0%(0/59) vs. 10.0%(8/80),χ²=4.552,P=0.033]. Compared with traditional three-port group, ZTP-LA group showed shorter operative time [(47.8±20.1) minutes vs. (66.0±27.3) minutes, t=4.383,P<0.001], shorter time to oral semi-fluid [(35.0±20.7) hours vs. (59.3±32.8) hours, t=5.158,P<0.001], shorter postoperative hospital stay [(4.1±1.6) days vs. (5.5±2.2) days, t=4.162, P<0.001], lower postoperative morbidity of complication [3.4% (2/59) vs. 18.1%(13/72), χ²=6.879, P=0.009], lower incidence of postoperative intra-abdominal abscess [0%(0/59) vs. 11.1%(8/72), χ²=5.179, P=0.023], lower incidence of paralytic ileus [1.7%(1/59) vs. 12.5%(9/72), χ²=3.946, P=0.047] and less cost during hospitalization[(13 585±2909) yuan vs.(16 861±5334) yuan, t=4.463, P<0.001]. ZTP-LA is safe, feasible and effective with advantages of faster recovery and less cost in the treatment of complicated appendicitis.

TRUNK MUSCLE ACTIVATION IN CHILDREN WITH SPASTIC DIPLEGIC CEREBRAL PALSY USING A HIPPOTHERAPY SIMULATOR

Purpose: To determine if there is a difference in trunk muscle activation in children with spastic diplegic cerebral palsy (CP) compared to typically developing (TD) children while being held in different positions on a hippotherapy simulator. Methods: Five children with spastic diplegic CP and five TD children of similar age were recruited through the Children’s Hospital of Wisconsin. The participants were held in static positions sitting on a hippotherapy simulator at 10[Formula: see text], 15[Formula: see text], and 20[Formula: see text] from the midline to front, back, and side positions. Surface electromyography (sEMG) data were collected from the left and right latissimus dorsi, hip adductor, middle trapezius, and rectus abdominis muscles. The pooled mean sEMG amplitude, at each position, served as the main outcome measurement. Results: The forward position at 20[Formula: see text] for the left and right lower rectus abdominis and right middle trapezius muscles had an effect size of [Formula: see text]. This was also evident in the right middle trapezius at 10[Formula: see text] in the forward and left tilted positions, and in the right latissimus dorsi at the 10[Formula: see text] left tilted position. Conclusion: Different sEMG in the abdominal, middle trapezius, and latissimus dorsi muscles in children with spastic diplegic CP suggests that utilizing a trunk position of different angles may improve the current therapeutic methods in the recruitment of trunk muscles.

Trunk muscle activity during different variations of the supine plank exercise

BackgroundExercises providing neuromuscular challenges of the spinal muscles are desired for core stability, which is important for workers with heavy manual labour as well as people recovering from back pain. PurposeThis study evaluated whether using a suspended modality increases trunk muscle activity during unilateral or bilateral isometric supine planks. DesignCross-sectional. MethodsTwenty university students participated in this cross-sectional study. Each subject performed four different conditions: bilateral stable supine plank, unilateral stable supine plank, bilateral suspended supine plank and unilateral suspended supine plank. Surface electromyography (EMG) signals were recorded for the upper rectus abdominis (UP ABS), lower rectus abdominis (LOW ABS), external oblique (OBLIQ) and lumbar erector spinae (LUMB). Peak EMG of the filtered signals were normalized to the maximum voluntary isometric contraction (MVIC). ResultsNo differences between exercises were found for UP ABS, LOW ABS and OBLIQ muscle activity. The unilateral suspended supine plank provided the highest LUMB activity (20% of MVIC) whiles the bilateral stable supine plank provided the lowest activity (11% of MVIC). ConclusionsThe combination of unilateral variations with a suspended support provides the greatest LUMB muscle activity, while using these variations separately only provides advantages when compared with regular planks.

Comparison of muscular activities in the abdomen and lower limbs while performing sit-up and leg-raise

[Purpose] This study compared the muscle activities of sit-up and leg-raise. [Subjects and Methods] The subjects of this study were healthy students in their 20s. For electromyography of sit-ups and leg-raises in the supine position, 5 muscle groups of the abdomen were selected for the attachment of sensors: the upper and lower rectus abdominis, external oblique, rectus femoris, and the iliopsoas. SPSS 20.0 was used for the statistical analysis. One-way ANOVA with repeated measures of all factors was performed to verify the statistical significance of the measurements taken for the muscle activities and follow-up verification was made with the Bonferroni post hoc test. [Results] Sit-up and leg raise showed a significant difference. The eccentric sit-up exercise elicited a significant increase in the activation of the abdominal muscle. The leg raise and eccentric sit-up exercises elicited significant increases in the activation of hip flexor muscle. [Conclusion] The eccentric sit-up had the most outstanding effect on the abdominal muscles involved in stability of the trunk.

Muscle Activation Among Supine, Prone and Side Position Exercises With and Without a Swiss Ball

PURPOSE: Prone, supine, and side position exercises are employed to enhance core stability, but how these exercises recruit trunk and extremity musculature compared to each other is unclear. The purpose of this study was to compare core muscle activity between supine position exercises (crunch, bent knee sit-up) and prone and side position exercises with or without a swiss ball. Both prone and side positions exercises were performed on the knees, on the toes, and on a swiss ball. METHODS: Eighteen healthy males and females between 23–45 years old served as subjects. Surface electrodes were positioned on the subject’s dominant side over the upper and lower rectus abdominis, external and internal obliques, rectus femoris, latissimus dorsi, and lumbar paraspinals. EMG data were collected from a Noraxon EMG system during five repetitions for 10 different exercises. Each repetition was performed in a slow and controlled manner, taking 3 s to complete followed by 1 s rest. EMG exercise data were normalized by maximum voluntary muscle contractions. Differences in muscle activity were assessed by a one-way repeated measures Analysis of Variance, with Tukey’s post hoc analysis used for pairwise comparisons. RESULTS: Prone position exercises were as effective or more effective compared to the supine position exercises in rectus abdominis recruitment (39-49±9-26%MVIC versus 35-53±13-19%MVIC), oblique recruitment (39-56±8-32%MVIC versus 31-36±11-17%MVIC), and latissimus dorsi recruitment (10-21±10-14%MVIC versus 2-8±1-3%MVIC). Side position exercises were not as effective in recruiting the rectus abdominis (14-26±7-15%MVIC) and internal oblique (17-28±1-12%MVIC), but were effective in recruiting the external oblique (37-62±26-37%MVIC). Lumbar paraspinal activity was low (5-7±2-3%MVIC) in all exercises except side position exercises (18-29±6-16%MVIC). Rectus femoris activity was low in all exercises (6-14±4-7%MVIC) except prone on ball with left hip extension (35±18%MVIC), bent knee sit-up (23±12%MVIC), and prone bridge on toes (20±7%MVIC). CONCLUSIONS: Prone position exercises are good alternatives to supine position exercises for recruiting core musculature. Side position exercises are better for oblique and lumbar paraspinal recruitment compared to rectus abdominis recruitment. Prone and side position exercises can be progressed from on knees to on toes and using a swiss ball.

Changes in Activation of Abdominal Muscles at Selected Angles During Trunk Exercise by Using Ultrasonography.

ObjectiveTo investigate the changes of activation of the abdominal muscles depending on exercise angles and whether the activation of rectus abdominis differs according to the location, during curl up and leg raise exercises, by measuring the thickness ratio of abdominal muscles using ultrasonography.MethodsWe examined 30 normal adults without musculoskeletal problems. Muscle thickness was measured in the upper rectus abdominis (URA), lower rectus abdominis (LRA), obliquus externus (EO), obliquus internus (IO), and transversus abdominis (TrA), at pre-determined angles (30°, 60°, 90°) and additionally at the resting angle (0°). Muscle thickness ratio was calculated by dividing the resting (0°) thickness for each angle, and was used as reflection of muscle activity.ResultsThe muscle thickness ratio was significantly different depending on the angles in URA and LRA. For curl up-URA p=0 (30°<60°), p=0 (60°>90°), p=0.44 (30°<90°) and LRA p=0.01 (30°<60°), p=0 (60°>90°), p=0.44 (30°>90°), respectively, by one-way ANOVA test-and for leg raise-URA p=0 (30°<60°), p=0 (60°<90°), p=0 (30°<90°) and LRA p=0.01 (30°<60°), p=0 (60°<90°), p=0 (30°<90°), respectively, by one-way ANOVA test-exercises, but not in the lateral abdominal muscles (EO, IO, and TrA). Also, there was no significant difference in the muscle thickness ratio of URA and LRA during both exercises. In the aspect of muscle activity, there was significant difference in the activation of RA muscle by selected angles, but not according to location during both exercises.ConclusionAccording to this study, exercise angle is thought to be an important contributing factor for strengthening of RA muscle; however, both the exercises are thought to have no property of strengthening RA muscle selectively based on the location.

Electromyographic activity of rectus abdominis muscles during dynamic Pilates abdominal exercises

To assess the electrical behaviour of the upper rectus abdominis (URA) and lower rectus abdominis (LRA) by electromyography (EMG) during the following dynamic Pilates abdominal exercises: roll up, double leg stretch, coordination, crisscross and foot work. The results were compared with EMG findings of traditional abdominal exercises (sit up and crunch). Seventeen female subjects (with no experience of the Pilates method) were recruited. The URA and LRA were evaluated while 12 isotonic contractions were performed using the Pilates principles or traditional abdominal exercises. The data were normalised by a maximal voluntary isometric contraction. Normality was accepted, and ANOVA followed by Tukey test was used to determine data differences (P < 0.05). Pilates exercises double leg stretch, coordination, crisscross and foot work promoted greater muscle activation than traditional exercises, mainly in URA. Thus, these exercises have the potential to be prescribed for muscle strengthening programmes.

The Pilates breathing technique increases the electromyographic amplitude level of the deep abdominal muscles in untrained people

To evaluate the behaviour of the upper rectus abdominis, lower rectus abdominis and transverse abdominis/internal oblique (TrA/IO) by using surface electromyography during trunk flexion with and without the Pilates breathing technique. Nineteen female subjects (without experience of the Pilates method) were recruited. The muscles were evaluated while trunk flexion was performed by using the Pilates breathing technique (POW) and Step Barrel device, followed by another contraction without the technique (NORM). Normality was accepted, and the paired t-test was used to determine data differences (p < 0.05). Significant differences were noted in the amplitude level of activation between TrA/IO-POW and TrA/IO-NORM. The activation amplitude level of TrA/IO-POW significantly increased compared with all the other muscles under the NORM condition. The breathing technique of the Pilates method associated with trunk flexion increases TrA/IO electrical activity.

Core muscle function during specific yoga poses

To assess the potential use of 11 yoga poses in specific training and rehabilitation programs via examination of the muscle activation patterns in selected trunk and hip muscles. Repeated-measures descriptive study. University laboratory, US. Thirty healthy yoga practitioners with more than 3 months yoga practice experience (mean age±SD, 32.0±12.3 y; 8 M/22 F) participated. Surface electromyographic signals of upper rectus abdominis, lower rectus abdominis, longissimus thoracis, external oblique abdominis and gluteus maximum muscle were recorded in 11 yoga poses: Halfway lift, Forward fold, Downward facing dog, Upward facing dog, High plank, Low plank, Chair, Mountain with arms down, Mountain with arms up, Warrior 1 (both sides). Root mean square values of each muscle during each pose, normalized by the maximal voluntary contraction. There were significant main effects of pose (p<.001) and muscle (p<.001), and a significant pose×muscle interaction (p=.001). The post hoc analysis revealed unique patterns for the five muscles of interest for each of the 11 poses (p<.024). Variations in core muscle firing patterns depend on the trunk and pelvic positions during these poses. Training programs can be developed by choosing particular poses to target specific core muscles for addressing low back pain and declines in performance. The High plank, Low plank and Downward facing dog poses are effective for strengthening external oblique abdominis, Chair and Warrior 1 poses for targeting gluteus maximum, and Chair and Halfway lift poses for strengthening longissimus thoracis. And these three muscles could be strengthened by the Upward facing dog pose.

Abdominal and Hip Flexor Muscle Activity During 2 Minutes of Sit-Ups and Curl-Ups

Previous studies have compared muscle activity between different types of sit-ups and curl-ups. However, few have examined the exercises used by the armed forces or investigated the influence of exercise duration on muscle activation. The aim of this study was to compare abdominal and hip flexor muscle activity between the style of sit-up used by the British Army and 4 variations of a curl-up, at the start, middle, and end of a 2-minute exercise period. Surface electromyograms (EMGs) were recorded from the upper and lower rectus abdominis, external oblique, transversus abdominis and internal oblique, and the rectus femoris (RF) of 23 British Army personnel. Isometric maximal voluntary contractions were used to normalize integrated EMGs to allow them to be compared between exercises. Curl-ups with arms crossed and feet restrained produced the highest integrated EMG in all the abdominal muscles (p < 0.05). Feet-restrained sit-ups and curl-ups also resulted in significantly higher activity in the RF than in nonrestrained versions of the curl-up (p < 0.001). The significant increase observed in muscle activity between the start and the end of the exercises (p < 0.001) was deemed to be in response to a reduction in force producing capacity of existing motor units. The RF experienced the greatest increase during exercises that activated the muscle the most, that is, sit-ups and curl-ups with feet restrained (p < 0.001). Previous research has indicated that such exercises produce high shear and compressive forces in the lower back, which can be injurious. Thus, if an organization wishes to assess the endurance of abdominal muscles, rather than hip flexors, then curl-ups without restraint of the feet should be performed instead of exercises in which the feet are restrained.

Conventional kinesiotherapy or Pilates mat exercises, what is more efficient for abdominal weakness? A feasibility study

The aim of this feasibility study was to contrast rectus abdominis (RA) muscle strength and electrical activity after two abdominal training protocols, conventional kinesiotherapy (CK) and Pilates mat exercises (PME). 13 participants were randomized to one of two groups: CK and PME, and were trained accordingly. The upper rectus abdominis (URA) and lower rectus abdominis (LRA) were independently examined and intra-group and inter-group comparison were done. Findings demonstrate a significant increase in RA strength after both protocols, relative to baseline. Significantly increased electrical activation was seen in the URA after CK. Training with PME, although as efficient as CK in strength improvement, produced decreased activation level of muscles. CK training induced an opposite result. The differences after training suggest that CK and PME training programmers may strength RA, but the neuromuscular activation strategies for that are not the same. PME can be incorporated into protocols to improve abdominals strength, and trunk stabilization.

Electromyographic Activity of the Rectus Abdominis During a Traditional Crunch and the Basic Jackknife Exercise with the Ab Lounge™

The use of nontraditional exercise devices such as the Ab Lounge™ has been promoted as being as effective as the traditional abdominal crunch in strengthening the abdominal musculature. Evidence for this is lacking, however. The purpose of this study was to compare the degree of activation of the upper and lower rectus abdominis using electromyography (EMG) during a traditional crunch with the basic jackknife using the Ab Lounge™. Twenty-two subjects (6 men and 16 women) were randomly selected from the student population at the University of the West Indies (Mona Campus). The mean age of the participants was 20.5 ± 1.5 years, height 166.4 ± 6.2 cm, weight 64 ± 10.3 kg, and waist-hip ratio 0.7 ± 0.1. Surface EMG was used to assess the muscle activity from the upper and lower rectus abdominis while each exercise was performed. The EMG data were full-wave rectified and normalized using a mathematical model that was set up in Microsoft Excel for Windows XP. Statistical analysis was performed on the data using a univariate analysis of variance with gender as a covariate. Significance was determined by p < 0.05. The mean EMG data recorded for the upper rectus abdominis was significantly higher with the traditional crunch when compared with the basic jackknife performed on the Ab Lounge™ (F = 4.39, p = 0.04). The traditional crunch produced a higher level of activity in the lower rectus abdominis when compared with the basic jackknife, but this was not statistically significant (F = 0.249, p = 0.62). There was no significant interaction between gender and the effect of the type of exercise on upper and lower rectus abdominis activation. These results suggest that the traditional abdominal crunch is more effective than the basic jackknife is in activating the rectus abdominis musculature.

평행봉 Tippelt 동작의 운동역학적 분석

This research was conducted to biomechanically analyze Tippelt motion in parallel bars, and establish technical understanding. To achieve that goal, the performances of the Tippelt acts carried out by five world top-class national gymnasts in the parallel bars 3-dimensional cinematographic analysis and EMG analysis were conducted and following conclusion were obtained. The Tippelt motions of excellent national gymnasts perform tap motion through the down swing of a large circular movements, and perform kick-out motion rapidly extending shoulder joint angle and hip joint angle with the trunk in a position close to perpendicular position at the vertical downwardness of the grasping the bars. At this time, if handstand starting the movement is too delayed or rapidly down swung, it was shown that from the initial falling, unnecessary muscular power was wasted in trapezius, anterior deltoid, erector spinae, latissimus dorsi, upper rectus abdominis, lower rectus abdominis. The muscular parts in tap motion generating muscle action potential were pectoralis major, rectus femoris, upper rectus abdominis, lower rectus abdominis, and those in kick-out motion were upper rectus abdominis, lower rectus abdominis, trapezius and anterior deltoid.

Electromyographic Response of the Abdominal Musculature to Varying Abdominal Exercises

This study examined the electromyographic (EMG) response of the upper rectus abdominis (URA), lower rectus abdominis (LRA), internal obliques (IOs), external obliques (EOs), and the rectus femoris (RF) during various abdominal exercises (crunch, supine V-up, prone V-up on ball, prone V-up on slide board, prone V-up on TRX, and prone V-up on Power Wheel). The subjects (n = 21) performed an isometric contraction of the abdominal musculature while performing these exercises. Testing revealed no statistically significant differences between any of the exercises with respect to the EOs, the URA, or the LRA. However, when examining the IO muscle, the supine V-up exercise displayed significantly greater muscle activity than did the slide exercise. In addition, EMG activity of the RF during the crunch was significantly less than in any of the other 5 exercises. These results indicate that when performing isometric abdominal exercises, non-equipment-based exercises stressed the abdominal muscles similarly to equipment-based exercises. Based on the findings of the current study, the benefit of training the abdominal musculature in an isometric fashion using commercial equipment could be called into question.

Comparison of 8 Abdominal Exercises using EMG and Exercise Preference

PURPOSE: To evaluate the effects of 8 different exercises on the myoelectric activity of the upper (URA) and lower rectus abdominis (LRA). Exercise preferences were also obtained. METHODS: Twenty-nine men (n=12) and women (n=17) aged 19.6±1.0y performed 8 randomly assigned abdominal muscle exercises: sit-up, crunch, Ab-Rocket, Bender Ball, Bean, Ab-Lounge, Ab-sling, and Stability Ball. Each participant performed 1 exercise per day on 8 nonconsecutive days. Each exercise was performed for 60 repetitions or failure at a cadence of 20 repetitions per minute. Surface electromyography (EMG) was recorded from the URA and LRA during each repetition. ANOVA with repeated measures compared EMG activity between exercises during the 10th repetition. Significance level was set at p ≤ 0.05 Participants also completed a questionnaire regarding their exercise preference and likelihood of equipment purchase. RESULTS: For the URA, the order of exercises from most to least EMG activity was; Ab-Sling, Ab-Rocket, crunch, sit-up, Stability ball, Bender Ball, Ab-Lounge, and Bean. The Ab-sling produced higher URA EMG activity than all other exercises (p<0.05). For the LRA, the order of exercises from most to least EMG activity was; Ab-Sling, sit-up, Ab-Rocket, crunch, Stability Ball, Bender Ball, Ab-Lounge, and Bean. The Ab-Sling produced higher EMG activity than all the other exercises (p<0.05) except the sit-up. Survey data revealed that 74% of participants would neither use nor purchase the Ab-sling or Ab-Rocket. CONCLUSIONS: For the 8 exercises examined in this study, the Ab-Sling, Ab-Rocket, crunch, and sit-up produced the most muscle activation in URA and LRA, but because participants would neither purchase nor use the Ab-Sling or Ab-Rocket, the sit-up or crunch should be prescribed for rectus abdominis exercise.