electromyographic evidence, the side-bridge exercise is the most effective technique to simultaneously activate the muscular spine stabilizers such as the external oblique (EO), internal oblique (IO), and quadratus lumborum (QL). 4 During this exercise, the 3 layers of the abdominal wall (the EO, IO, and
Chi-Whan Choi, Jung-Wan Koo and Yeon-Gyu Jeong
James W. Youdas, Hannah E. Baartman, Brian J. Gahlon, Tyler J. Kohnen, Robert J. Sparling and John H. Hollman
be directed to movement at its distal end. Trunk muscles such as the external oblique, internal oblique, rectus abdominis, and erector spinae provide spinal stabilization, so the prime mover muscles (pectoralis major, anterior deltoid, serratus anterior, and triceps brachii) can generate forceful arm
Timothy J. Gibbons and Marie-Louise Bird
), internal oblique abdominis (IO), and external oblique abdominis (EO). 9 Real-time ultrasound is used extensively in musculoskeletal investigations and has advantages when applied in rehabilitation. 11 Figure 1 —Image of Oov. The primary objective of this study was to compare ultrasound measurements of TrA
Rodrigo Cappato de Araújo, Vinícius Yan Santos Nascimento, Rafaela Joyce Barbosa Torres, Francis Trombini-Souza, David Behm and Ana Carolina Rodarti Pitangui
seventh rib (SA_7th), external oblique (EO) and internal oblique (IO) muscles, 7 channels from the system EMG1232C (EMG System do Brasil Ltda ® , São José dos Campos, Brazil) were used. The EMG recordings were obtained through self-adhesive electrodes (Ag/AgCl sensor). The electrodes were positioned in a
Kristi Edgar, Aimee Appel, Nicholas Clay, Adam Engelsgjerd, Lauren Hill, Eric Leeseberg, Allison Lyle and Erika Nelson-Wong
, Inc, Olstykke, Denmark) were applied over 6 bilateral muscle groups (Figure 1 ): external obliques, internal obliques, erector spinae (ES) (L1 level), GMed, GMax, and lateral hamstrings (HS). All electrode placements were confirmed through palpation and manual resistance. Raw EMG signals were
Lukas D. Linde, Jessica Archibald, Eve C. Lampert and John Z. Srbely
upward and inward toward their spine 14 while the abdominal bracing technique involved a contraction to induce mild tension of the abdominal girdle. 10 Abdominal hollowing primarily targets the transverse abdominis and internal oblique muscles 8 , 9 whereas bracing induces a generalized activation of
Han-Kyu Park, Dong-Woo Kim and Tae-Ho Kim
. The sampling rate for the signals was set to 1500 Hz. The maximal voluntary isometric contraction measurement positions of both internal oblique (IO) and external oblique (EO) muscles were measured using Kendall’s technique. 30 The maximal voluntary isometric contraction of each muscle was performed
Dean C. Hay, Mark P. Wachowiak and Ryan B. Graham
Advances in time-frequency analysis can provide new insights into the important, yet complex relationship between muscle activation (ie, electromyography [EMG]) and motion during dynamic tasks. We use wavelet coherence to compare a fundamental cyclical movement (lumbar spine flexion and extension) to the surface EMG linear envelope of 2 trunk muscles (lumbar erector spinae and internal oblique). Both muscles cohere to the spine kinematics at the main cyclic frequency, but lumbar erector spinae exhibits significantly greater coherence than internal oblique to kinematics at 0.25, 0.5, and 1.0 Hz. Coherence phase plots of the 2 muscles exhibit different characteristics. The lumbar erector spinae precedes trunk extension at 0.25 Hz, whereas internal oblique is in phase with spine kinematics. These differences may be due to their proposed contrasting functions as a primary spine mover (lumbar erector spinae) versus a spine stabilizer (internal oblique). We believe that this method will be useful in evaluating how a variety of factors (eg, pain, dysfunction, pathology, fatigue) affect the relationship between muscles’ motor inputs (ie, activation measured using EMG) and outputs (ie, the resulting joint motion patterns).
Samuel J. Howarth, Tyson A.C. Beach and Jack P. Callaghan
The goal of this study was to quantify the relative contributions of each muscle group surrounding the spine to vertebral joint rotational stiffness (VJRS) during the push-up exercise. Upper-body kinematics, three-dimensional hand forces and lumbar spine postures, and 14 channels (bilaterally from rectus abdominis, external oblique, internal oblique, latissimus dorsi, thoracic erector spinae, lumbar erector spinae, and multifidus) of trunk electromyographic (EMG) activity were collected from 11 males and used as inputs to a biomechanical model that determined the individual contributions of 10 muscle groups surrounding the lumbar spine to VJRS at five lumbar vertebral joints (L1-L2 to L5-S1). On average, the abdominal muscles contributed 64.32 ± 8.50%, 86.55 ± 1.13%, and 83.84 ± 1.95% to VJRS about the flexion/extension, lateral bend, and axial twist axes, respectively. Rectus abdominis contributed 43.16 ± 3.44% to VJRS about the flexion/extension axis at each lumbar joint, and external oblique and internal oblique, respectively contributed 52.61 ± 7.73% and 62.13 ± 8.71% to VJRS about the lateral bend and axial twist axes, respectively, at all lumbar joints with the exception of L5-S1. Owing to changes in moment arm length, the external oblique and internal oblique, respectively contributed 55.89% and 50.01% to VJRS about the axial twist and lateral bend axes at L5-S1. Transversus abdominis, multifidus, and the spine extensors contributed minimally to VJRS during the push-up exercise. The push-up challenges the abdominal musculature to maintain VJRS. The orientation of the abdominal muscles suggests that each muscle primarily controls the rotational stiffness about a single axis.
Jeffrey M. Willardson, Fabio E. Fontana and Eadric Bressel
To compare core muscle activity during resistance exercises performed on stable ground vs. the BOSU Balance Trainer.
Twelve trained men performed the back squat, dead lift, overhead press, and curl lifts. The activity of the rectus abdominis, external oblique abdominis, transversus abdominis/internal oblique abdominis, and erector spinae muscles was assessed. Subjects performed each lift under three separate conditions including standing on stable ground with 50% of a 1-RM, standing on a BOSU Balance Trainer with 50% of a 1-RM, and standing on stable ground with 75% of a 1-RM.
Significant differences were noted between the stable 75% of 1-RM and BOSU 50% of 1-RM conditions for the rectus abdominis during the overhead press and transversus abdominis/internal oblique abdominis during the overhead press and curl (P < .05). Conversely, there were no significant differences between the stable 75% of 1-RM and BOSU 50% of 1-RM conditions for the external obliques and erector spinae across all lifts examined. Furthermore, there were no significant differences between the BOSU 50% of 1-RM and stable 50% of 1-RM conditions across all muscles and lifts examined.
The current study did not demonstrate any advantage in utilizing the BOSU Balance Trainer. Therefore, fitness trainers should be advised that each of the aforementioned lifts can be performed while standing on stable ground without losing the potential core muscle training benefits.