Transversus Abdominis Activation Research Articles

Postoperative early initiation of sequential exercise program in preventing persistent spinal pain syndrome type-2 after modified transforaminal lumbar interbody fusion: a prospective randomized controlled trial.

This prospective randomized controlled trial aimed to investigate the impact of early postoperative sequential motor control (starting first day post-operatively) and core stabilization training (starting fifth week post-operatively) compared to conventional exercise (starting fifth weeks post-operatively) on the risk of developing persistent spinal pain syndrome type-2 (PSPS-T2). 395 patients with lumbar degenerative diseases (LDDs) undergoing modified transforaminal lumbar interbody fusion and a 12-week postoperative exercise program (sequential vs. conventional exercise: 214 vs. 181) were evaluated for low back pain (LBP) intensity, Oswestry Disability Index (ODI), pressure pain threshold (PPT), temporal summation (TS), fatty infiltration of paraspinal muscles, transversus abdominis (TrA) activation capacity and Fear-Avoidance Beliefs Questionnaire (FABQ) pre-operatively, 3 months post-operatively, and 1 year post-operatively. At 3-month postoperative assessment, LBP in sequential exercise group were lower than those in conventional exercise group (P < 0.05), and sequential-exercise patients had greater local-area PPTs, lower TS, lower TrA activation capacities and less fatty infiltration of erector spinae than did the conventional-exercise patients (P < 0.05). At 1-year postoperative assessment, fewer sequential-exercise patients had PSPS-T2 compared with conventional-exercise patients (11/214 vs. 20/181; P < 0.05). LBP at rest and FABQ were lower in sequential-exercise patients than conventional-exercise patients (P < 0.05). Furthermore, both PPT and TS at 1-year postoperative assessment were associated with these measurements at 3-month postoperative assessment in patients with PSPS-T2 (P < 0.05). Postoperative sequential exercise has more positive effects to avoid PSPS-T2 than conventional exercise in patients with LDDs possibly because of its advantages in improving central and peripheral sensitization.

Yoga, Physical Therapy and Home Exercise Effects on Chronic Low Back Pain: Pain Perception, Function, Stress, and Quality of Life in a Randomized Trial.

Low back pain is a common health problem. In this study, we investigated the effects of yoga, physical therapy (PT), and home exercise (HE) on pain perception, function, stress, and quality of life in chronic low back pain (cLBP). We randomly assigned 54 participants to three distinct treatment groups: (a) a physical therapy group (PT) who received spinal stabilization exercises (SSE) combined with local heat and transcutaneous electrical stimulation; (b) a home exercise group (HE) who received SSE as part of the home program; and (c) a yoga group who received yoga exercises. The primary outcome measures were a Visual Analog Scale (VAS) for measuring pain, and the Oswestry Disability Index (ODI) to measure function. Secondary outcome measures were the Tampa Kinesiophobia Scale (TKS), Central Sensitization Inventory (CSI), pain sensitivity (L3 and deltoid R/L PPTs), Spielberger State-Trait Anxiety Inventory (STAI), plasma cortisol and DHEA-S levels, Transversus Abdominis (TrA) muscle activation, and the Nottingham Health Profile (NHP). Assessments were conducted before and after a six-week intervention period. All three groups demonstrated improvements in pain on the VAS, function on the ODI, pain sensitivity on the L3 and deltoid R/L PPTs, CSI, anxiety on the STAI, TrA muscle activation, and quality of life on the NHP (p < .05). The PT group exhibited a more pronounced improvement on the ODI score (p < .05) than the other groups. Cortisol levels only decreased in the PT group (p < .05). The exercises did not impact DHEA-S and NHP-S parameters. Thus, all interventions resulted in decreased stress, pain intensity, pain sensitivity, central sensitization, and improved function and quality of life; there was no singularly superior approach between interventions. These findings will aid in tailoring treatment programs for managing cLBP according to individual needs.

Understanding musculoskeletal disorders in dancers: The role of lumbopelvic muscles and movement competency

ObjectiveTo investigate whether transversus abdominis activation (TrA), hip strength, and movement competency are associated with the incidence of musculoskeletal disorder episodes (MDEs) in dancers when controlling for confounding variables. The secondary objectives were to determine if there were differences between professional and preprofessional dancers for the aforementioned factors, as well as to determine if there were differences in TrA activation and hip strength between the dominant and non-dominant sides. DesignProspective cohort study. Methods118 dancers were recruited. The independent variables were collected at the beginning of the dance season: 1) TrA activation, 2) hip strength, and 3) movement competency. To assess the development of MDEs, a weekly electronic diary was used over a 38-week period. MDEs were compiled for each dancer's whole body and subdivided into total musculoskeletal disorder episodes (all body parts) and lower quadrant musculoskeletal disorder episodes (lower limb and lower back). ResultsLower TrA, as well as higher hip abductor and external rotator strength, were associated with a lower incidence of MDEs. TrA activation (β = 0.260, p = 0.023) and hip external rotator strength (β = −0.537, p = 0.002) could significantly explain 25.4% of the variance of total MDEs, as well as 20.9% of the variance of lower quadrant musculoskeletal disorder episodes (β = 0.272, p = 0.016; β = −0.459, p = 0.011). No significant associations were found between movement competency and MDEs. ConclusionsHigher hip strength could be a protective factor for MDEs among dancers. Further studies are needed to better understand the involvement of the transversus abdominis in MDEs.

Ultrasound imaging of core muscles activity in multiparous women with vaginal laxity: a cross-sectional study

Vaginal laxity (VL) is a common condition among multiparous women, especially those who have delivered vaginally. Since pelvic floor muscles (PFMs) work synergistically with other core muscles, physical therapy protocols that aim to treat VL should train the PFMs in combination with other core muscles. To investigate the activity of core muscles in multiparous women with and without VL, and its relation to sexual function. An observational, cross-sectional study. The study included 100 multiparous women, who were divided into two groups according to their scores on the vaginal laxity questionnaire (VLQ). Women who scored between 1 and 3 on the VLQ were categorized as having VL (n = 48), while those who scored between 5 and 7 were placed in the control group (n = 52). The primary outcomes were PFM displacement, diaphragmatic excursion, transversus abdominis activation ratio, and lumbar multifidus thickness measured by ultrasound imaging. The secondary outcome was sexual functioning, evaluated using the Arabic female sexual function index (ArFSFI). The VL group had significantly lower PFM displacement (mean difference (MD) − 0.42; 95% confidence interval (CI) − 0.49 to − 0.33; p = 0.001), diaphragmatic excursion (MD − 2.75; 95% CI − 2.95 to − 2.55; p = 0.001), lumbar multifidus thickness (MD − 10.08; 95% CI − 14.32 to − 5.82; p = 0.02), and ArFSFI scores (MD − 9.2; 95% CI − 10.59 to − 7.81; p = 0.001) in comparison to the control group (p < 0.05). Nevertheless, the transversus abdominis activation ratio demonstrated no significant difference between the two groups (MD 0.06; 95% CI − 0.05 to 0.17; p = 0.33). Multiparous women with VL had significantly lower PFM displacement, diaphragmatic excursion, lumbar multifidus thickness, and sexual function index scores than women in the control group. The only exception was transversus abdominis activation, which did not differ significantly between the VL and control groups.

Effectiveness of in-group versus individually administered pain neuroscience education on clinical and psychosocial outcomes in patients with chronic low back pain: randomized controlled study protocol.

(1) This trial will compare the clinical and psychosocial effectiveness of in-group and individually pain neuroscience education (PNE) in patients with chronic low back pain (CLBP). In addition, (2) the influence of social determinants of health on post-treatment results will be analyzed. A three-arm randomized controlled trial will be conducted. Sixty-nine participants with CLBP will be recruited in a 1:1:1 ratio. Participants, assessor, and statistician will be blinded to group assignment. The PNE intervention will be adapted to the context of the participants. An experimental group (n=33) will receive PNE in an in-group modality, the other experimental group (n=33) will receive PNE in an individually modality and the control group (n=33) will continue with usual care. Additionally, participants will be encouraged to stay active by walking for 20-30 min 3-5 times per week and will be taught an exercise to improve transversus abdominis activation (bracing or abdominal following). The outcome measures will be fear avoidance and beliefs, pressure pain threshold, pain self-efficacy, catastrophizing, pain intensity, and treatment expectation. Outcome measures will be collected at one-week before intervention, immediately post-intervention, and four-weeks post-intervention. The innovative approach of PNE oriented to fear beliefs proposed in this study could broaden the application strategies of this educational therapeutic modality. Impact. Contextualized PNE delivered by physical therapist could be essential to achieve a good cost-effectiveness ratio of this intervention to improve the clinical condition of people with CLBP.

Analyzing muscle thickness changes in lateral abdominal muscles while exercising using virtual reality.

[Purpose] Virtual reality (VR) rehabilitation has become popular in the medical field. VR-guided exercises (VR-ge) have demonstrated positive effects on gait and trunk control. Trunk muscle activation, particularly that of the transversus abdominis (TrA), is responsible for these improvements. However, the difference in muscle activation between VR and real space remains unclear. Therefore, this study aimed to clarify the differences in trunk muscle activation during exercise therapy performed in VR and real space. [Participants and Methods] A total of 22 healthy male volunteers were divided into two equal groups: VR-ge and Control exercise (C-e) groups. Both groups performed reaching exercises in a seated position. Ultrasound imaging was used to measure the thicknesses of the right external oblique, internal oblique, and TrA muscles, both at rest and during the reaching exercises performed in six different directions. [Results] No significant differences were observed in TrA muscle thickness changes between the groups before the intervention. However, after the intervention, the VR-ge group showed significantly greater TrA muscle thickness changes during reaching compared to that of the C-e group. [Conclusion] VR-ge increased TrA activation during reaching compared to exercising in real space.

Comparison of transversus abdominis activation characteristics between healthy and chronic low back pain population during upright functional movement.

Previous literature suggests that transversus abdominis (TrA) activation is diminished in chronic low back pain (cLBP) subjects compared to healthy subjects in less-functional positions. However, few studies have investigated the effects of upright functional movement on TrA activation in cLBP individuals. This pilot study aimed to compare TrA activation characteristics in healthy and cLBP subjects during the movement of double leg standing (DLS) to single leg standing (SLS) and to a 30∘ single leg quarter squat (QSLS). TrA activation was determined by the percentage change in TrA thickness from DLS to SLS and DLS to QSLS. TrA thickness was measured in 14 healthy and 14 cLBP participants using ultrasound imaging with a probe holder at 20mm and 30mm from the fascia conjunction point. At both measurement points (20 and 30mm), there were no significant main effects of body sides, lower limb movements and the interactions between them on TrA activations between the healthy and cLBP participants even after covariates were adjusted for (all p> 0.05). Results from this study suggest the evaluation of TrA activation during upright functional movements as part of an assessment for cLBP management may not be suggested.

Transversus Abdominis Ultrasound Thickness during Popular Trunk-Pilates Exercises in Young and Middle-Aged Women.

The transversus abdominis (TrA) is a core muscle that contributes to functional mobility and lumbar stability. This study aimed to compare the changes in TrA thickness during different Pilates exercises, and to identify the exercise that elicited the greatest TrA activation. Forty-four healthy women were divided into two groups: young (25-35 years old) and middle-aged (36-55 years old). TrA thickness was assessed by ultrasound while the participants performed five Pilates exercises: basic position, hundred, hip roll, side plank, and dead bug. A repeated measures analysis of variance revealed that the dead bug exercise induced a significantly higher increase in TrA thickness (relative to rest) than the other exercises (p < 0.05). The young group also showed a significantly higher overall TrA thickness than the middle-aged group (p < 0.05). The findings suggest that the dead bug exercise is the most effective for enhancing TrA activation among the Pilates exercises tested. The basic position and the hundred exercises can be used as warm-up exercises before performing more challenging exercises such as the hip roll, the side plank, and the dead bug. The sequence of exercises can be similar for both young and middle-aged women.

Lunar and mars gravity induce similar changes in spinal motor control as microgravity.

Introduction: Once more, plans are underway to send humans to the Moon or possibly even to Mars. It is therefore, important to know potential physiological effects of a prolonged stay in space and to minimize possible health risks to astronauts. It has been shown that spinal motor control strategies change during microgravity induced by parabolic flight. The way in which spinal motor control strategies change during partial microgravity, such as that encountered on the Moon and on Mars, is not known. Methods: Spinal motor control measurements were performed during Earth, lunar, Mars, and micro-gravity conditions and two hypergravity conditions of a parabola. Three proxy measures of spinal motor control were recorded: spinal stiffness of lumbar L3 vertebra using the impulse response, muscle activity of lumbar flexors and extensors using surface electromyography, and lumbar curvature using two curvature distance sensors placed at the upper and lower lumbar spine. The participants were six females and six males, with a mean age of 33years (standard deviation: 7years). Results: Gravity condition had a statistically significant (Friedmann tests) effect spinal stiffness (p < 0.001); on EMG measures (multifidus (p = 0.047), transversus abdominis (p < 0.001), and psoas (p < 0.001) muscles) and on upper lumbar curvature sensor (p < 0.001). No effect was found on the erector spinae muscle (p = 0.063) or lower curvature sensor (p = 0.170). Post hoc tests revealed a significant increase in stiffness under micro-, lunar-, and Martian gravity conditions (all p's < 0.034). Spinal stiffness decreased under both hypergravity conditions (all p's ≤ 0.012) and decreased during the second hypergravity compared to the first hypergravity condition (p = 0.012). Discussion: Micro-, lunar-, and Martian gravity conditions resulted in similar increases in spinal stiffness, a decrease in transversus abdominis muscle activity, with no change in psoas muscle activity and thus modulation of spinal motor stabilization strategy compared to those observed under Earth's gravity. These findings suggest that the spine is highly sensitive to gravity transitions but that Lunar and Martian gravity are below that required for normal modulation of spinal motor stabilization strategy and thus may be associated with LBP and/or IVD risk without the definition of countermeasures.

Measuring transversus abdominis activity using pressure biofeedback unit-A technical report.

Pressure biofeedback is a tool that can detect the movement of a structure and may be used as an indicator of muscle function. It's widely used to measure the transversus abdominis (TrA) muscle activity. Pressure biofeedback (PBU) monitors the abdominal wall movement by measuring the pressure change during abdominal hollowing and can indirectly evaluate the TrA muscle function, which is considered as a valuable tool. The evaluation of the training of core muscles, including the transversus abdominis, requires a reliable outcome. Various methods using different positions are used to evaluate the transversus abdominis muscle function. However, it is noted that a standard way of evaluation and training still needs to be improved in research and clinical practice. This technical report discusses the optimal position and technique to measure the TrA muscle activity using PBU, with discussions on the merits and demerits of the body positions. The technical report is presented with a literature review of the PBU measurement of TrA and through observation in the clinical practice. The evaluation methods of TrA, including the position to activate and isolate, are discussed in detail. Training core muscles does not imply TrA activation, and evaluating isolated TrA and multifidus is essential before intervention. The abdominal drawing-in maneuver effectively activates TrA in various evaluation positions of the body, but when using PBUs, it would be valid in a prone position. Different body positions are practiced to train TrA and core muscles using PBU, commonly adopted by practice are in supine. It's noted that most of the studies lack in establishing the effectiveness of the position in evaluating the TrA muscle activity using PBU. The need for insight into an appropriate technique for evaluating TrA activity is addressed in this technical report. This report presents key points on the complete technique and concludes that the prone position is superior to other positions and recommended for measuring and recording the TrA activity using a PBU.

A Correction Method for Muscle Stiffness Sensors to Measure Transversus Abdominis Activity

The transversus abdominis muscle is important for various human functions, including the prevention of back pain and the use of muscle activity values as an indicator for the treatment of urinary incontinence. Measuring muscle activity is an effective means of evaluating whether correct training has been performed. The transversus abdominis muscle stiffness sensor developed in a previous study used a method in which a belt with a sensor attached was wrapped around the lower back, which made measurement simple but also caused problems owing to the influence of phenomena other than muscle activity on the measurement data. Therefore, we propose a novel correction method to calculate the muscle activity of this sensor accurately, which can be used for simple measurements. We propose a formula to compensate for effects other than muscle activity based on a model equation that includes contact conditions and belt tension, which affect the muscle stiffness sensor value. We evaluated the validity of the correction equation from simulations and the change in similarity owing to the correction by simultaneously measuring the muscle action potentials and muscle stiffness sensor values during breathing movements with muscle activity. The proposed correction method improved the muscle stiffness data during respiration and contraction. It is possible to improve the measurement accuracy by improving the calibration method and hardware.

Effects of Sensorimotor Training on Transversus Abdominis Activation in Chronic Low Back Pain Patients.

(1) Background: The aim of this study was to investigate and compare the effect of sensorimotor training on transversus abdominis activation. (2) Methods: Seventy-five patients with chronic low back pain were randomly assigned to one of three groups (whole body vibration training using Galileo®, coordination training using Posturomed®, or physiotherapy (control)). Transversus abdominis activation was measured by using sonography pre- and post-intervention. Second, changes in clinical function tests and their correlation with the sonographic measurements were determined. (3) Results: All three groups showed an improvement in activation of the transversus abdominis post-intervention, with the Galileo® demonstrating the largest improvement. There were no relevant (r > 0.5) correlations between activation of the transversus abdominis muscle and any clinical tests. (4) Conclusions: The present study provides evidence that sensorimotor training on the Galileo® significantly improves the activation of the transversus abdominis muscle.

Reciprocal activation changes of lower extremity muscles caused by the abdominal hollowing maneuver in patients with unilateral lumbar disc herniation: an electromyography study

Aim: Decreased or delayed multifidus and transversus abdominis (TrA) activity, transition of the TrA from tonic to phasic activity, and increased activity in the more superficial erector spinae muscles are behaviors unique to people with lumbar disc herniation (LDH). This study investigates whether the abdominal hollowing maneuver (AHM), which activates the TrA, can improve the rates of impaired muscle reciprocal activation of the lower extremities due to unilateral LDH during walking, tandem walking, and stair climbing activities.Material and Method: The healthy and affected lower extremities of 17 patients with unilateral LDH were analyzed. The participants performed three activities and three times without the AHM. For the walking activity, the participants took a total of eight steps without deviating from their normal gait pattern. For the tandem walking activity, the participants covered the eight-step distance by performing heel-to-toe walking. For the stair climbing activity, the participants climbed a total of four steps without support from their upper extremities. The researchers visually checked the postures of the participants during all stages of the activities. The ratio of tibialis anterior (TA) and medial gastrocnemius (MGC) electromyographic values that emerged during the activities to the maximum voluntary isometric contraction (MVIC) values of these muscles was called MVIC%. Then the MVIC% values of the TA and MGC were matched, and the muscle reciprocal activation ratio ("MVIC%"-TA/"MVIC%"-MGC) was determined. While the activities were being performed, the MVIC% values of both muscles were measured separately without and with the AHM.Results: Reliability values ranged from 0.87 to 0.99, with an SEM of 2.22 to 11.98. The ICC3,1 was considered “good” or “excellent” for all muscle surface electromyography measurements. During the tandem walking activity performed with the AHM, the reciprocal activation rates of TA: MGC on the affected and healthy legs converged (p=0.010, d=0.71). However, TA: MGC reciprocal activation rates did not differ between the affected and healthy extremities in the walking (p=0.519, d=0.16) or stair climbing (p=0.180, d=0.35) activities performed with the AHM.Conclusion: According to the results of the study, integration of the AHM into tandem walking activity brought the reciprocal activation rates of both legs closer to each other and enabled them to exhibit similar behaviors, even without adherence to any exercise protocol. Therefore, tandem walking can be selected as an appropriate activity to combine with spinal stabilization exercises performed by unilateral L4-L5 radiculopathy patients using the AHM along with the task.

Age-related changes in transversus abdominis activation and myofascial structure in healthy adults using ultrasound imaging

Age-related changes in transversus abdominis activation and myofascial structure in healthy adults using ultrasound imaging

The Relationship between Transversus Abdominis and Internal Oblique Thickness and Disease-Related Characteristics in Parkinson's Disease

Background and Aim: The core muscles are essential for spinal stability during functional activities. Trunk muscle function is affected by specific neurodegenerative processes of Parkinson's disease (PD). This study aimed to investigate whether changes in transversus abdominis (TrA) and internal oblique (IO) thickness during the abdominal drawing-in maneuver (ADIM) were associated with clinical manifestations, core endurance, and functional mobility in patients with PD. Materials and Methods: We included patients with a modified Hoehn and Yahr staging of 3 or lower. TrA and IO muscle thickness were measured using ultrasound both at rest and during ADIM, and the percent change (%) was calculated to assess TrA and IO activation. Patients performed core endurance (prone bridge and sit-ups) and functional mobility tests (timed “up and go” [TUG] and five times sit-to-stand [FTSTS]). All assessments were conducted during the “on” phase. Results: Five female and 17 male patients were included in this study. We found a statistically significant correlation between ultrasound parameters of IO and the clinical manifestations of PD (P &lt; 0.05). Correlations were observed between TrA percent change and prone bridge, sit-ups, TUG, and FTSTS (P &lt; 0.05). Conclusion: To the best of our knowledge, this is the first ultrasound imaging-based study to demonstrate the relationship between TrA and IO muscle thickness and clinical outcomes, and functional performance in patients with PD. Percentage changes in IO were associated with the clinical manifestations of PD. Increased activation of TrA during ADIM was associated with improved core endurance and mobility. The results suggest that a trunk-specific exercise program may be the cornerstone in the treatment of PD-related changes.

Movement Competency Screen: Rethinking the Rating

Background Dancers are at high risk of musculoskeletal disorders. There has been a growing interest in the last few years in pre-season screening using tools to evaluate movement competency, among which is the Movement Competency Screen (MCS). It is currently scored using a categorical 3-level rating system, but this method does not seem to take into account the load level of movements. A 5-level scoring system could potentially alleviate this problem. Hypothesis/Purpose For each scoring system, to investigate (1) the internal consistency, and (2) the association with transversus abdominis activation (TrA), hip muscle strength and with Functional Movement screen (FMSTM) total score. Study design Secondary analyses of a prospective cohort study. Methods One hundred and eighteen professional and preprofessional dancers evolving in ballet or contemporary dance were recruited. The MCS was performed and was scored according to the 3- and 5-level scoring systems. The key variables for movement competency that were considered for convergent validity were the activation ratio of the TrA evaluated with ultrasound imaging and hip strength assessed with a handheld dynamometer. Movement competency was also measured with the FMSTM. Results Internal consistency was higher for the 5-level scoring of the MCS items ( α=0.548) compared to the 3-level scoring system ( α=0.494). Multiple linear regressions showed that TrA activation, hip adductor strength, and FMSTM could significantly explain 24.0% of the variance for the 5-level scoring system of the MCS whereas hip internal rotator strength and FMSTM could explain only 16.4% of the variance for the 3-level scoring system. Conclusion The 5-level scoring system showed better metrologic properties in terms of internal consistency and concurrent validity and therefore, should be preferred over the 3-level scoring system in future research. Level of Evidence Level III

Neuromuscular adaptations to experimentally induced pain in the lumbar region: systematic review and meta-analysis.

Experimental pain models are frequently used to understand the influence of pain on the control of human movement. In this systematic review, we assessed the effects of experimentally induced pain in the lumbar region of healthy individuals on trunk muscle activity and spine kinematics. Databases were searched from inception up to January 31, 2022. In total, 26 studies using either hypertonic saline injection (n = 19), heat thermal stimulation (n = 3), nociceptive electrical stimulation (n = 3), or capsaicin (n = 1) were included. The identified adaptations were task dependent, and their heterogeneity was partially explained by the experimental pain model adopted. Meta-analyses revealed an increase of erector spinae activity (standardized mean difference = 0.71, 95% confidence interval [CI] = 0.22-1.19) during full trunk flexion and delayed onset of transversus abdominis to postural perturbation tasks (mean difference = 25.2 ms, 95% CI = 4.09-46.30) in the presence of pain. Low quality of evidence supported an increase in the activity of the superficial lumbar muscles during locomotion and during voluntary trunk movements during painful conditions. By contrast, activity of erector spinae, deep multifidus, and transversus abdominis was reduced during postural perturbation tasks. Reduced range of motion of the lumbar spine in the presence of pain was supported by low quality of evidence. Given the agreement between our findings and the adaptations observed in clinical populations, the use of experimental pain models may help to better understand the mechanisms underlying motor adaptations to low back pain.

Expiratory and inspiratory action of transversus abdominis during eupnea and hypercapnic ventilation

BackgroundRecently, there is interest in the clinical importance of monitoring abdominal muscles during respiratory failure. The clinical interpretation relies on the assumption that expiration is a passive physiologic process and, since diaphragm and abdomen are arranged in series, any inward motion of the abdominal wall represents a sign of diaphragm dysfunction. However, previous studies suggest transversus abdominis might be active even during eupnea and is preferentially recruited over the other abdominal muscles. Objective1) Is transversus abdominis normally recruited during eupnea? 2) What is the degree of activation of transversus abdominis during hypercapnia? 3) Does the end-inspiratory length of transversus abdominis change during hypercapnia, while diaphragm function is normal? MethodsIn 30 spontaneously breathing canines, awake without confounding anesthetic, we measured directly both electrical activity and corresponding mechanical length and shortening of transversus abdominis during eupnea and hypercapnia. ResultsTransversus abdominis is consistently recruited during eupnea. During hypercapnia, transversus abdominis recruitment is progressive and significant. Throughout hypercapnia, transversus abdominis baseline end-inspiratory length is not constant: baseline length decreases progressively throughout hypercapnia.After expiration, into early inspiration, transversus abdominis shows a consistent neural mechanical post -expiratory expiratory activity (PEEA) at rest, which progressively increases during hypercapnia. ConclusionTransversus abdominis is an obligatory expiratory muscle, reinforcing the fundamental principle expiration is not a passive process. Beyond expiration, during hypercapnic ventilation, transversus abdominis contributes as an “accessory inspiratory muscle” into the early phase of inspiration. Clinical monitoring of abdominal wall motion during respiratory failure may be confounded by action of transversus abdominis.

Effectiveness of Early Postpartum Rectus Abdominis versus Transversus Abdominis Training in Patients with Diastasis of the Rectus Abdominis Muscles: A Pilot Randomized Controlled Trial.

To determine feasibility of a randomized controlled trial (RCT) comparing postpartum rectus abdominis training with transversus abdominis training in reducing the inter-recti distance in patients with diastasis of the rectus abdominis muscles (DRAM). A pilot, randomized controlled trial with longitudinal assessment following vaginal delivery at 6 and 12 weeks postpartum was completed. Forty-four women with DRAM (inter-recti distance of ≥30mm as measured by digital calipers) were recruited from a regional public hospital in Australia. The standard treatment group (n=21) was provided with a 5-second transversus abdominis activation exercise in crook lying. The experimental group (n=23) was provided with a 1-second rectus abdominis crunch exercise. Dosage was between 1-10 repetitions at baseline and between 1-20 at 6 weeks, twice a day, at least 5 days per week, prescribed depending on individual participant ability. The primary outcome measure was inter-recti distance. Feasibility measures were recruitment rate, loss to follow-up, adverse events, and exercise adherence. The rectus abdominis group achieved greater reduction of the inter-recti distance at 6 weeks (at and below the umbilicus) and 12 weeks (above, below, and at the umbilicus). Recruitment rate was acceptable (45%) and there were no adverse events, but loss to follow-up was high due to COVID-19 impacts and participants did not return exercise adherence diaries. Prescription of rectus abdominis exercise during the early postpartum period following vaginal delivery resulted in a greater reduction of the inter-recti distance at 6 and 12 weeks when compared with transversus abdominis exercise. This pilot trial was impacted by high loss to follow up due to COVID-19 restrictions, but feasibility was otherwise acceptable. The findings of the study will inform future fully powered trials comparing these two exercise types in postpartum women with DRAM.

Can rehabilitative ultrasonography imaging utilised for activation of transversus abdominis in asymptomatic population?: A double-blinded randomised controlled-trial

Can rehabilitative ultrasonography imaging utilised for activation of transversus abdominis in asymptomatic population?: A double-blinded randomised controlled-trial