Asymmetry in internal oblique muscle thickness: Not the key to a cricket fast bowler's performance

Author(s):  
Benita Olivier ◽  
Franso-Mari Olivier ◽  
Nkazimulo Mnguni ◽  
Oluchukwu Loveth Obiora

Purpose Previous studies found that trunk muscle asymmetry may play a role in preventing injury in cricket fast bowlers, while the association with bowling performance has not been investigated. This study aims to describe the side-to-side differences in trunk muscle thickness and determine the association between bowling performance and these side-to-side differences in trunk muscle thickness in adolescent fast bowlers. Methods In this observational cross-sectional study, bowling performance, namely ball release speed and bowling accuracy, was recorded in adolescent fast bowlers. Ultrasound imaging measured external oblique, internal oblique, transversus abdominis and lumbar multifidus muscle thickness. Results Fast bowlers (n = 46) with a mean age of 15.9 (±1.2) years participated. On the non-dominant side, the external oblique and internal oblique at rest were thicker than on the dominant side (external oblique: p = 0.011, effect size = 0.27; internal oblique: p < 0.0001, effect size = 0.40), while the transversus abdominus ( p = 0.72, effect size = 0.19) and lumbar multifidus ( p = 0.668, effect size = 0.04) were symmetrical. Weak correlations existed between bowling performance and the side-to-side differences in the thickness in all muscles, except for two moderate correlations: 1. The smaller the side-to-side difference in absolute thickness of the external oblique when contracted, the faster the ball release speed (Spearman's (ρ) = −0.455, p = 0.002). 2. Also, a smaller side-to-side difference in external oblique contraction ratio (Spearman's (ρ) = −0.495, p = 0.0001) was associated with faster ball release speed. Conclusions No relationship between bowling performance and side-to-side differences in internal oblique muscle thickness could be established, while more symmetrical external oblique muscles may be linked to faster ball release speeds.

Healthcare ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 496
Author(s):  
Sachiko Madokoro ◽  
Masami Yokogawa ◽  
Hiroichi Miaki

We evaluated the trunk abdominal muscle thickness while performing different exercises to identify the most effective training and to investigate the subjective difficulty associated with exercising. Twenty-eight men (mean age: 21.6 ± 0.9 years) without orthopedic diseases were enrolled. Ultrasonic imaging was used to measure the thickness of the transversus abdominis (TA), internal oblique, and external oblique muscles while at rest and while performing the abdominal draw-in maneuver and abdominal bracing. Measurements were made in the supine and sitting positions, and the subjective difficulty in performing each exercise was examined using a 5-level evaluation scale. The TA and internal oblique muscle thicknesses were significantly greater during the abdominal draw-in maneuver (ADIM) than during bracing or resting, in the supine and sitting positions. The subjective difficulty of abdominal bracing (AB) was graded significantly higher than that of ADIM. Additionally, a correlation between subjective difficulty and muscle thickness was found for the TA and IO. Our results may contribute to the choice of more effective exercises for spinal stability.


1992 ◽  
Vol 36 (10) ◽  
pp. 742-746
Author(s):  
Christopher A. Hamrick ◽  
Sean Gallagher

Trunk muscle activity of twelve healthy males with coal mining experience was examined while each subject lifted a box under various conditions. The independent variables were four levels of posture (kneeling, stooped under a 1.2 m roof, stooped under a 1.6 m roof, and standing), height to which the box was lifted (35 cm or 70 cm), and weight of the lifting box (15 kg, 20 kg, or 25 kg). The dependent variables were the peak EMG values recorded during a lift for each of eight trunk muscles (left and right erectores spinae, left and right latissimus dorsi, left and right external oblique, and left and right rectus abdominis). Posture and weight of lift significantly affected peak activity of the left and right erectores spinae, the left and right latissimus dorsi muscles, and the right external oblique muscle. The latissimus dorsi muscle activity was highest in the low stooping posture, and was lowest in the kneeling posture, while erectores spinae activity was highest in the kneeling posture and decreased as the trunk became more flexed. Thus, the muscle activity during lifting tasks is affected by restricting a worker's posture. Consequently, many lifting guidelines and recommendations currently in use may not be directly applicable to work being performed in restricted postures.


Author(s):  
Yuki Kurokawa ◽  
Satoshi Kato ◽  
Satoru Demura ◽  
Kazuya Shinmura ◽  
Noriaki Yokogawa ◽  
...  

BACKGROUND: Abdominal bracing is effective in strengthening the trunk muscles; however, assessing performance can be challenging. We created a device for performing abdominal trunk muscle exercises. The effectiveness of this device has not yet been evaluated or compared OBJECTIVE: We aimed to quantify muscle activity levels during exercise using our innovative device and to compare them with muscle activation during abdominal bracing maneuvers. METHODS: This study included 10 men who performed abdominal bracing exercises and exercises using our device. We measured surface electromyogram (EMG) activities of the rectus abdominis (RA), external oblique, internal oblique (IO), and erector spinae (ES) muscles in each of the exercises. The EMG data were normalized to those recorded during maximal voluntary contraction (%EMGmax). RESULTS: During the bracing exercise, the %EMGmax of IO was significantly higher than that of RA and ES (p< 0.05), whereas during the exercises using the device, the %EMGmax of IO was significantly higher than that of ES (p< 0.05). No significant difference was observed in the %EMGmax of any muscle between bracing exercises and the exercises using the device (p= 0.13–0.95). CONCLUSIONS: The use of our innovative device results in comparable activation to that observed during abdominal bracing.


2019 ◽  
Vol 03 (01) ◽  
pp. E12-E18
Author(s):  
Vidar Andersen ◽  
Marius Fimland ◽  
Atle Saeterbakken

AbstractThe aim of the study was to compare the one-armed vs. two-armed American kettlebell swing on trunk muscle activation. Fifteen resistance-trained men performed ten repetitions of both exercises using a 14-kg kettlebell. Surface EMG from the erector spinae, rectus abdominis and external oblique muscles were collected on both sides of the trunk. The erector spinae activation during the one-armed swing was 14–25% higher on the contralateral compared to the ipsilateral side in both exercises (Cohen’s d effect size [ES]=0.41–0.71, p ˂ 0.001–0.034). Further, the contralateral side was 14% more activated during the two-armed swing compared to the ipsilateral side during the one-armed swing (ES=0.43, p=0.009). For the rectus abdominis muscle, the two-armed swing induced higher activation of the rectus abdominis compared to the one-armed swing on both the contralateral (40%, ES=0.48, p=0.040) and ipsilateral side (59%, ES=0.83, p=0.002). There were no differences for the external oblique muscle (p=0.495–0.662). In conclusion, the trunk activation patterns of the two exercises were different, which could be explained by different biomechanics in the two exercises, and could thus have complimentary effects. We recommend that both unilateral and bilateral execution of the American kettlebell swing is included over time.


2021 ◽  
pp. 1-6
Author(s):  
Eun-Joo Jung ◽  
Jin-Wook Sung ◽  
In-Joon Uh ◽  
Jae-Seop Oh

BACKGROUND: Active straight leg-raise (ASLR) is often performed to strengthen abdominal muscles. The correct execution and maximum benefit of the ASLR can be achieved using abdominal hollowing (AH) and abdominal bracing (AB) exercises. OBJECTIVE: To compare the effects of AH and AB on transverse abdominis (TrA), internal oblique, and external oblique thicknesses, as well as on the pelvic rotation angle, in healthy women during active ASLR. METHODS: The participants in this study were assigned randomly to either the AH (n= 15) or AB groups (n= 15). During ASLR, abdominal muscle thickness was measured using ultrasound and pelvic rotation was measured using a Smart KEMA device. Each trial was repeated three times for 5 s each. RESULTS: The thickness of the TrA was significantly greater during ASLR with AH than during ASLR with AB (p< 0.001). In contrast, there was no respective significant change in the thickness of the external oblique (p> 0.0.311) or internal oblique (p> 0.818). Pelvic rotation angle was significantly reduced during ASLR with AB, compared with ASLR with AH (p< 0.018). CONCLUSIONS: We recommend that AH be performed for the selective contraction of TrA during ASLR, and that AB be performed for the prevention of the pelvic rotation during ASLR. Therefore, AH and AB should be separately done in stabilization exercises.


2001 ◽  
Vol 204 (13) ◽  
pp. 2371-2381 ◽  
Author(s):  
Mathew M. Fife ◽  
Carmen L. Bailey ◽  
David V. Lee ◽  
David R. Carrier

SUMMARYIn trotting dogs, the pattern of activity of the obliquely oriented hypaxial muscles is consistent with the possible functions of (i) stabilization against vertical accelerations that cause the trunk to sag in the sagittal plane and (ii) stabilization against forces that tend to shear the trunk in the sagittal plane. To test these hypotheses, we compared the amount of activity of the intercostal and abdominal oblique muscles (i) when dogs carried additional mass (8–15% of body mass) supported over the limb girdles versus supported mid-trunk (test of sagittal bounce), and (ii) when dogs trotted up versus down a 10° slope (test of sagittal shear). In response to the loading manipulations, only the internal oblique muscle responded in a manner that was consistent with stabilization of the trunk against forces that cause the trunk to sag sagittally. In contrast, when the fore–aft forces were manipulated by running up- and downhill, all four of the monitored muscles changed their activity in a manner consistent with stabilization of the trunk against sagittal shearing. Specifically, muscles with a craniodorsal orientation (external oblique and external intercostal muscles) showed an increase in activity when the dogs ran downhill and a decrease when they ran uphill. Muscles with a cranioventral orientation (internal oblique and internal intercostal muscles) exhibited the opposite pattern: increased activity when the dogs ran uphill and decreased activity when they ran downhill. Changes in activity of two extrinsic appendicular muscles, the serratus ventralis and deep pectoralis, during uphill and downhill running were also consistent with the sagittal shearing hypothesis. In contrast, changes in the level of recruitment of the oblique hypaxial muscles were not consistent with stabilization of the trunk against torques that induce yaw at the girdles. Hence, we suggest that the oblique hypaxial muscles of trotting dogs act to stabilize the trunk against sagittal shearing torques induced by limb retraction (fore–aft acceleration) and protraction (fore–aft deceleration).


2015 ◽  
Vol 50 (2) ◽  
pp. 147-155 ◽  
Author(s):  
Nam G. Lee ◽  
Joshua (Sung) H. You ◽  
Tae H. Kim ◽  
Bong S. Choi

Context: The exact neuromechanical nature and relative contribution of the abdominal drawing-in maneuver (ADIM) to postural instability warrants further investigation in uninjured and injured populations. Objective: To determine the effects of the ADIM on static core and unipedal postural stability in nonathletes with core instability. Design: Controlled laboratory study. Setting: University research laboratory. Patients or Other Participants: A total of 19 nonathletes (4 women: age = 22.3 ± 1.3 years, height = 164.0 ± 1.7 cm, mass = 56.0 ± 4.6 kg; 15 men: age = 24.6 ± 2.8 years, height = 172.6 ± 4.7 cm, mass = 66.8 ± 7.6 kg) with core instability. Intervention(s): Participants received ADIM training with visual feedback 20 minutes each day for 7 days each week over a 2-week period. Main Outcome Measures(s): Core instability was determined using a prone formal test and measured by a pressure biofeedback unit. Unipedal postural stability was determined by measuring the center-of-pressure sway and associated changes in the abdominal muscle-thickness ratios. Electromyographic activity was measured concurrently in the external oblique, erector spinae, gluteus medius, vastus medialis oblique, tibialis anterior, and medial gastrocnemius muscles. Results: All participants initially were unable to complete the formal test. However, after the 2-week ADIM training period, all participants were able to reduce the pressure biofeedback unit by a range of 4 to 10 mm Hg from an initial 70 mm Hg and maintain it at 60 to 66 mm Hg with minimal activation of the external oblique (t18 = 3.691, P = .002) and erector spinae (t18 = 2.823, P = .01) muscles. Monitoring of the pressure biofeedback unit and other muscle activations confirmed that the correct muscle contraction defining the ADIM was accomplished. This core stabilization was well maintained in the unipedal-stance position, as evidenced by a decrease in the center-of-pressure sway measures (t18 range, 3.953–5.775, P &lt; .001), an increased muscle-thickness ratio for the transverse abdominis (t18 = −2.327, P = .03), and a reduction in external oblique muscle activity (t18 = 3.172, P = .005). Conclusions: We provide the first evidence to highlight the positive effects of ADIM training on core and postural stability in nonathletes with core instability.


2020 ◽  
Vol 33 (5) ◽  
pp. 857-863
Author(s):  
Sun-Young Ha ◽  
DooChul Shin

BACKGROUND: The curl-up exercise is widely used in clinical practice for strengthening abdominal muscles, but has been applied without a systematic method. OBJECTIVE: The purpose of this study was to determine the most effective method considering the angle and muscle contraction direction during the curl-up exercise. METHODS: Fourteen healthy males performed the curl-up exercise according to contraction direction (concentric and eccentric) and angle (30∘, 60∘, and 90∘). The muscle activity of the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and iliopsoas (IP) was measured using electromyography (EMG), and the muscle thickness of transversus abdominis (TrA) was measured using ultrasonography. RESULTS: The activities of the abdominal muscles (RA, EO, and IO) decreased with increasing angles (30∘, 60∘, and 90∘) (p< 0.05). There was no significant difference between eccentric and concentric contractions. The thickness ratio of TrA was the largest at an eccentric curl-up at 30∘, and the smallest at a concentric curl-up at 30∘ (p< 0.05). CONCLUSIONS: The most effective angle for curl-up was 30∘. Although there is no difference in the direction of muscle contraction, eccentric curl-up at 30∘ could be considered the most effective posture for abdominal strengthening considering the importance of TrA.


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