Diaphragm and core stabilization exercises in low back pain: A narrative review.

INTRODUCTION: Core stabilization is a vital concept in clinical rehabilitation (including low back pain rehabilitation) and competitive athletic training. The core comprises of a complex network of hip, trunk and neck muscles including the diaphragm. AIMS: The paper aims to discuss the role of the diaphragm in core stability, summarize current evidence and put forth ideal core training strategies involving the diaphragm. METHOD: Narrative review RESULTS: The diaphragm has a dual role of respiration and postural control. Evidence suggests that current core stability exercises for low back pain are superior than minimal or no treatment, however, no more beneficial than general exercises and/or manual therapy. There appears to be a higher focus on the transversus abdominis and multifidi muscles and minimal attention to the diaphragm. We propose that any form of core stabilization exercises for low back pain rehabilitation should consider the diaphragm. Core stabilization program could commence with facilitation of normal breathing patterns and progressive systematic restoration of the postural control role of the diaphragm muscle. CONCLUSION: The role of the diaphragm is often overlooked in both research and practice. Attention to the diaphragm may improve the effectiveness of core stability exercise in low back pain rehabilitation.

Surface electromyography analysis of core stabilizing muscles during isometric shoulder contractions in athletes with low back pain.

BACKGROUND: The study was carried out in the athletes with and without Low Back Pain (LBP) to determine the surface electromyography activity of core stabilizing muscles while performing isometric shoulder and trunk contractions. STUDY DESIGN: Cross-sectional study. METHODS: This study enlisted the participation of 40 athletes. Group A included 20 athletes (18 males and 2 females) without LBP, and Group B included 20 athletes (12 males and 8 females) with LBP. Athletes with LBP were assessed using the Modified Oswestry Disability Questionnaire (MODQ) and Visual Analog Scale (VAS) to determine their level of disability and pain severity, respectively. EMG activity of the rectus abdominis, external oblique, longissimus, and multifidus was recorded in both groups as they performed bilateral isometric shoulder and trunk contractions. RESULTS: In the LBP group, EMG activity of the rectus abdominis and external oblique muscles was significantly lower (P < 0.05). The LBP group had significantly more multifidus activity (P = 0.03) than the NLBP group. Among all the exercises, bilateral isometric shoulder extension contraction activated the rectus abdominis, right external oblique, and longissimus group of muscles significantly more (P < 0.05) in both groups. In both groups, bilateral isometric shoulder flexion contraction resulted in significantly higher multifidus muscle activation (P = 0.002). CONCLUSION: The activation of core stabilizing muscles was altered in athletes with LBP. When athletes are unable to contract and activate trunk muscles owing to pain, upper extremity exercises can be used to activate these muscles.

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

BACKGROUND AND PURPOSE: 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. METHODS: 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. RESULTS: 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. DISCUSSION: 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.

Electromagnetic field for supramaximal muscle stimulation: A retrospective study of safety, efficacy, and patient satisfaction in Brazil.

BACKGROUND: Currently, even individuals who do physical activity regularly have some degree of dissatisfaction with their own bodies. The electromagnetic field for supramaximal muscle contraction has been the subject of research. High-intensity supramaximal muscle stimulation (HI-SMS) is a non-invasive technology used to strengthen, firm, and tone the abdominal muscles, arms, buttocks, and thighs and has been indicated for aesthetic purposes. AIMS: The present study aimed to examine the safety and efficacy of HI-SMS used in the abdominal muscles of patients through the analysis of clinical evaluation, biochemical serum profile, and patient satisfaction with the procedure. PATIENTS/METHODS: This is retrospective non-randomized and non-controlled study collected in a private clinic; all data from healthy participants (n = 25), aged between 18 and 55 years, were compiled and analyzed. All received eight 30 min sessions of electromagnetic field ONIX HI-SMS (intensity of the 90%-100%) located in abdominal, twice a week with intervals of 2-3 days. RESULTS: The results show that BMI, fat thickness, and waist circumference improved the body contour after the treatment. There was no statistical difference in the data referring to the values of AST, ALT, ALP, creatinine, cholesterol, LDL-C, VLDL-C, HDL-C, glycemia, LDH, CK, and IL-6. However, there was a reduction of "non-esterified" free fatty acids when compared to baseline. This treatment provided high levels of tolerance, comfort, and high level of satisfaction. CONCLUSIONS: Thus, it can be suggested that the treatment with HI-SMS in abdominal muscles proves to be a safe technology with potential for non-invasive therapy for aesthetic purposes.

Effect of Motor Control Training on Trunk Muscle Morphometry, Pain, and Disability in People With Chronic Low Back Pain: A Systematic Review and Meta-Analysis.

OBJECTIVE: The aim of this systematic review and meta-analysis was to study the effects of motor control training (MCT) on trunk muscle morphometry measured by ultrasound imaging and pain and disability in individuals with chronic low back pain. METHODS: PubMed, Web of Science, Scopus, and Cochrane Library databases were searched from study inception until January 2021. Randomized control trials evaluating both muscle morphometry and pain or disability in individuals with chronic low back pain were included. Study selection, data extraction, and quality assessment were performed by 2 reviewers independently. Modified Downs and Black tool and the Grading of Recommendations Assessment, Development and Evaluation approach were used to assess the risk of bias and quality of evidence, respectively. A meta-analysis was performed using a random effects model with mean difference or standardized mean difference (SMD). RESULTS: Of 3459 studies initially identified, 15 studies were included, and 13 studies were selected for meta-analysis. The results revealed no differences in the resting thickness of the transversus abdominis, internal and external oblique, and lumbar multifidus muscles in studies that compared MCT with other interventions. The transversus abdominis muscles contraction ratio was greater (SMD = 0.93; 95% confidence interval [CI], -0.0 to 1.85) and lower pain (weighted mean difference: -1.07 cm; 95% CI, -1.91 to -0.22 cm; P = .01) and disability (SMD = -0.86; 95% CI, -1.42 to -0. 29; P < .01) scores were found in the groups who underwent MCT compared with other interventions. CONCLUSION: This systematic review and meta-analysis found that motor control exercise training increased the transverse abdominis contraction ratio (muscle activation) and improved the level of pain and disability compared to other interventions in people with chronic low back pain. However, motor control exercise training was not superior to other interventions in increasing the resting thickness of deep abdominal and lumbar multifidus muscles in intervention times less than 12 weeks.

Core musculature co-contraction during suspension training exercises.

Suspension training reportedly enhances core musculature co-contraction. This study investigated whether the use of a suspension trainer increases core musculature co-activation during exercises vs. its floor counterpart. Participants were 25 healthy volunteers (16 men, 9 women; age: 27.24 ± 4.02 years). Wireless electromyography electrodes were placed bilaterally at the rectus abdominis (RA), erector spinae (ES), and abdominal obliques (OB). Test order (push-up, bridge, and prone plank) was randomized (exercise and condition) with a 3-min rest period between tests. Co-contraction ratios between muscle groups were estimated by root mean square. Ratios (RA/ES, RA/OB, ES/OB) were analyzed using paired t-tests (P ≤ .05). For all floor exercises, co-contraction of core musculature was significantly higher than suspension trainer. During suspension training, perturbations due to increased agonist activation without similar increases in antagonists may be too intense for untrained or injured individuals. Individuals lacking muscle control to recruit muscles concurrently may benefit from mastering traditional floor exercises to promote joint stiffness and stability before suspension trainer exercises.

Effects of mouthpiece shape and expiratory threshold loading on contraction of the lateral abdominal muscles: A cross-sectional study.

BACKGROUND: Expiratory tasks may facilitate transversus abdominis (TrA) activity for spinal stabilization. The purpose of this study was to verify whether a combination of pursed-lip breathing (PLB) and use of an expiratory threshold loading (ETL) device to increase expiratory resistance would promote TrA contraction comparable to that for a stabilization exercise. METHODS: Twenty healthy men performed expiratory tasks or an abdominal drawing-in maneuver (ADIM). Expiratory tasks comprised combinations of ETL settings with 0%, 5%, or 15% of maximum expiratory pressure, and mouthpieces with a normal shape or pursed-lip shape. B-mode ultrasound imaging of the TrA, internal oblique, and external oblique muscles was performed to determine percentage changes in muscle thickness. Percentage changes among tasks were statistically compared for each muscle. FINDINGS: TrA thickness increased with normal lips at 15% ETL, with PLB with 5% ETL, and with ADIM (p < 0.01 each). Internal oblique thickness increased under all PLB conditions (p < 0.01 each). No significant differences in external oblique thickness were seen for any tasks. The total thickness of the lateral abdominal muscles was significantly increased not only for 15% ETL tasks and ADIM, but also for PLB with 5% ETL (p < 0.02 each). INTERPRETATION: These results indicated that PLB with 5% ETL could facilitate the same level of TrA activity as the ADIM. PLB with 5% ETL was the only task that simultaneously increased overall lateral abdominal muscles, including the internal obliques, and might be readily applicable in clinical situations.

Comparative effects of selected abdominal and lower limb exercises in the recruitment of the pelvic floor muscles: Determining adjuncts to Kegel's exercises.

PURPOSE: This study evaluated the electrical activities of the pelvic floor muscles in response to selected abdominal and hip adductor exercises, using the Kegel's maneuver as a gold standard, to compare the efficacies of these maneuvers in pelvic floor muscles recruitment to guide their informed utilization as adjuncts for Kegel's exercises. METHOD: Twenty-one postpartum mothers with recent vaginal deliveries performed six trials, including the typical Kegel's exercise; two abdominal exercises (curl-up and abdominal hollowing); two hip adductor exercises (adductor ball squeeze and auto-resisted hip adduction); and a combination of abdominal, hip adductor and pelvic floor muscle contractions (combo). Pelvic floor muscles activities were monitored via surface electromyography during each 5-s trial. Data were analyzed with descriptive statistics and inferential statistics of one way ANOVA at p < 0.05. RESULTS: Generally, the pelvic floor muscles were statistically significantly (p < 0.001) most active during the combo trial, compared to other trials. Comparing the two abdominals, Kegel's and combo trials, pelvic floor muscles activity was least during the curl-up contraction (p < 0.001). On the other hand, Kegel's trial elicited the lowestpelvic floor muscles activity when compared with the combo and two adductor trials (p < 0.001). CONCLUSION: Abdominal and hip adductor exercises are recommended adjuncts of Kegel's exercise but the combo maneuver was the most effective in activating the pelvic floor muscles.

Comparison of two different feedback techniques for activating the transversus abdominis: An observational study.

BACKGROUND: The transversus abdominis (TrA) is an important muscle for spinal stabilization. The abdominal draw-in maneuver (ADIM) is a method that selectively activates the TrA without overactivation of the external oblique (EO) and internal oblique (IO). Individuals with low back pain may have trouble in understanding proper contraction of the TrA. OBJECTIVE: The aim of this study was to investigate the differences between two feedback techniques to re-educate the TrA. METHODS: One hundred eighty healthy volunteers (123 female, 57 male) were randomized into two groups. The ADIM was performed with different feedback methods: conventional (verbal and tactile) feedback and visual feedback from real-time ultrasound images. RESULTS: A within-group comparison revealed a significant increase in the thickness of the TrA, IO, and EO during the ADIM (p< 0.001) in both groups. The mean change (SD) in the thickness of the TrA and IO between rest and the ADIM was an increase of 2.541.25 and 1.882.14 in group 1 and 1.821.27 and 1.241.87 in group 2, respectively (p< 0.001). No significant differences were observed in EO thickness between the two groups. CONCLUSIONS: Although visual biofeedback shows a greater effect on ADIM training, both approaches are applicable, and clinicians may decide on which to use based on their clinical environment and experience.

Comparison of the Pressure Biofeedback Unit and Real-Time Ultrasound Imaging as Feedback Tools to Contract the Transversus Abdominis Muscle: A Randomized Controlled Trial in Healthy Older Adults.

BACKGROUND AND PURPOSE: The transversus abdominis (TrA) is a key muscle for lumbar stabilization and is often retrained in physical therapy. Feedback tools, such as the pressure biofeedback unit (PBU) and rehabilitative ultrasound imaging (RUSI), are frequently used by physical therapists to train their patients and improve their patients' ability to contract this muscle. However, the effect of these tools in rehabilitating the TrA in older adults remains to be demonstrated, as is their efficiency in transferring the skill of recruiting the TrA from a supine position to a standing position.The objective of the study was to compare the immediate effectiveness of the PBU and RUSI to reeducate the TrA muscle in a population of asymptomatic older adults (without pain). METHODS: Forty participants were randomized into 2 groups (RUSI or PBU). The intervention included a training session involving 15 TrA contractions held for 10 seconds with the corresponding feedback device. The dependent variable, TrA thickness (a muscle activation indicator), was measured using ultrasound images before and after the intervention in a supine and standing position. Nonparametric analyses were used for inter- and intragroup comparisons. RESULTS AND DISCUSSION: The results showed no between-group differences in TrA activation ratio (AR) in the supine or standing position (supine AR: TrA RUSI thickness change P = .53 vs PBU thickness change P = .73, comparison between groups P = .51; standing AR: TrA RUSI thickness change P = .003 vs PBU thickness change P = .10; comparison between groups P = .61). However, the change in TrA thickness compared to the other abdominal wall muscles in a standing position was significantly less post-intervention for the RUSI group only (RUSI P = .006 vs PBU P = .72). Both groups remained similar post-intervention for this outcome (P = .20). CONCLUSIONS: Neither the RUSI nor the PBU seems to have the desired effect on the activation of TrA in asymptomatic older adults.

Application of Feedback Type on Performance of Abdominal Drawing-In Maneuver in Healthy Adults: A Quasi-Experimental Study of Motor Control and Motor Learning.

OBJECTIVE: The aim of this study was to compare the effects of verbal, tactile-verbal, and visual feedback on muscle activation of the lumbar stabilizers relative to extremity movers during an abdominal drawing-in maneuver when feedback is withheld. METHODS: This quasi-experimental study equally divided 54 healthy adults into 3 feedback groups (verbal, tactile-verbal, and visual) who trained twice per week over a 4-week period to perform supine abdominal drawing-in maneuvers. The percentage of maximum voluntary isometric contraction of rectus abdominis, multifidus (MF), erector spinae, and hamstrings (HS) as an outcome measure was acquired using surface electromyography. A 2-way factorial analysis of variance with bootstrapping allowed for comparison of post-pre difference scores across the interaction of feedback and muscle groups. RESULTS: Hamstring activation decreased in those receiving tactile-verbal feedback relative to an increase in participants given visual feedback. Furthermore, when using verbal feedback, HS activity increased relative to a decline in rectus abdominis, and when presenting visual feedback, HS activity increased relative to a decrease in MF. However, no post-pre changes were seen across muscles with tactile-verbal feedback. CONCLUSION: Although tactile-verbal feedback did not increase MF recruitment, it produced less HS activity than visual feedback. Undesirable HS recruitment may reflect boredom or feedback dependency.

The control of respiratory pressures and neuromuscular activation to increase force production in trained martial arts practitioners.

PURPOSE: The mechanisms that explain the ability of trained martial arts practitioners to produce and resist greater forces than untrained individuals to aid combat performance are not fully understood. We investigated whether the greater ability of trained martial arts practitioners to produce and resist forces was associated with an enhanced control of respiratory pressures and neuromuscular activation of the respiratory, abdominal, and pelvic floor musculature. METHODS: Nine trained martial arts practitioners and nine untrained controls were instrumented with skin-surface electromyography (EMG) on the sternocleidomastoid, rectus abdominis, and the group formed by the transverse abdominal and internal oblique muscles (EMGtra/io). A multipair oesophageal EMG electrode catheter measured gastric (Pg), transdiaphragmatic (Pdi), and oesophageal (Pe) pressures and EMG of the crural diaphragm (EMGdi). Participants performed Standing Isometric Unilateral Chest Press (1) and Standing Posture Control (2) tasks. RESULTS: The trained group produced higher forces normalised to body mass2/3 (0.033 ± 0.01 vs. 0.025 ± 0.007 N/kg2/3 mean force in Task 1), lower Pe, and higher Pdi in both tasks. Additionally, they produced higher Pg (73 ± 42 vs. 49 ± 19 cmH2O mean Pg) and EMGtra/io in Task 1 and higher EMGdi in Task 2. The onset of Pg with respect to the onset of force production was earlier, and the relative contributions of Pg/Pe and Pdi/Pe were higher in the trained group in both tasks. CONCLUSION: Our findings demonstrate that trained martial arts practitioners utilised a greater contribution of abdominal and diaphragm musculature to chest wall recruitment and higher Pdi to produce and resist higher forces.

The influence of the trunk muscle activation on occlusion pressure and respiratory muscle strength in healthy participants: Randomized controlled trial.

OBJECTIVES: The purpose of the study was to check if the trunk muscle activation done in accordance with rules of the Bobath concept affects the occlusion pressure and respiratory muscle efficacy in forced breathing manoeuvres in healthy participants. DESIGN: Randomized controlled trial. Between-subjects design. PARTICIPANTS: Seventy-four healthy volunteers, aged 20-26 years, were recruited from medical students, randomly assigned to the experimental or control groups. INTERVENTION: The intervention in the experimental group was individual physiotherapy based on the Bobath concept. It was provided by qualified physiotherapist and lasted about 60 min. The Bobath concept is an inclusive, individualized therapeutic approach to optimize movement recovery, informed by contemporary movement and neuro-sciences. The control group participated in a 45-minute lecture on the importance of the stability of trunk muscle and the diaphragm position that is adequate for its respiratory work. The described interventions, in both groups, were performed once, between the initial and final measurement of the respiratory drive. OUTCOME MEASURES: The subjects underwent two assessments of the following variables: occlusion pressure (P0.1) and the respiratory muscle strength: maximal inspiratory pressure (PImax), maximal expiratory pressure (PEmax), maximal occlusion pressure (P0.1max) with the use of MasterScope Spirometer. In experimental group, the physiotherapy assessment was carried out before intervention. RESULTS: As a result of the applied intervention, P0.1 in the experimental group increased (p = 0.001; 82.45 vs 103.73), which was not observed in the control group (p = 0.629; 88.95 vs 85.83). The intervention did not change the results of all other outcomes including P0.1 max; PImax and PEmax. CONCLUSION: The activation of trunk muscles such as transversus abdominis, multifidius and muscles of the pelvic floor was found to improve the effectiveness of diaphragmatic work during tidal breathing as measured with P0.1 values. Established abdominal pressure, which stabilizes the trunk and prevents chest mobility, might be the reason why forced measurements (PImax, PEmax, P.01 max) remain unchanged.

Transverse abdominis activity and ultrasound biofeedback in college golfers with and without low back pain.

OBJECTIVES: To compare transverse abdominis (TrA) muscle activity in college golfers with and without a history of low back pain (LBP) and examine the effects of ultrasound biofeedback and a functional golf-setup position on TrA activity. DESIGN: Crossover study. SETTING: Laboratory. PARTICIPANTS: Thirty-two (n = 32) collegiate golfers were stratified into either the LBP group (n = 16, 4.6 ± 4.5 LBP episodes) or non-LBP group (n = 16, 0.1 ± 0.3 LBP episodes) based on LBP episodes in the last 6-months. MAIN OUTCOME MEASURES: Ultrasound measures of TrA activity were performed during standard contractions and contractions with ultrasound biofeedback. Contraction-type order was randomized between two visits. Testing was performed in two positions, supine and golf-setup positions. RESULTS: We observed no significant differences in TrA activity between the LBP and non-LBP groups. Overall, TrA activity was greater during biofeedback contractions compared to standard contractions, and TrA activity was lower in the golf-setup position compared to the supine position. CONCLUSIONS: We observed no differences in TrA activity between college golfers with and without LBP. College golfers with and without LBP demonstrated a greater ability to contract their TrA with real-time ultrasound biofeedback and a lower ability to contract their TrA in the functional golf-setup position compared to the traditional supine position.

Cognitive Behavioral Therapy With Stabilization Exercises Affects Transverse Abdominis Muscle Thickness in Patients With Chronic Low Back Pain: A Double-Blinded Randomized Trial Study.

OBJECTIVE: Nonspecific chronic low back pain (NCLBP) is a major public health and global socioeconomic burden with a variety of symptoms, such as fear-avoidance behaviors. This study aimed to evaluate the effect of cognitive behavioral therapy (CBT) associated with stabilization exercise (SE) on thickness of transverse abdominis (TrA) muscle in patients with NCLBP. METHODS: Forty patients with NCLBP were randomly assigned into experimental CBT associated with SE (n = 20) and control groups without SE (n = 20). Transverse abdominis muscle thickness was assessed during abdominal drawing in maneuver (ADIM) and active straight leg raise (ASLR) of the right lower limb using ultrasound imaging. Fear-avoidance belief and disability were evaluated using a fear-avoidance belief questionnaire (FABQ) and a Roland-Morris disability questionnaire (RMDQ) before and after intervention. RESULTS: Mixed-model analysis of variance indicated that the effect of time was significant for the right and left TrA contraction thickness during ADIM and left TrA contraction thickness during ASLR (P < .05). However, the experimental group exhibited higher right and left TrA muscle thickness compared with the control group during ADIM (P = .001). Moreover, there were no significant differences between groups in the thickness of TrA muscle during ASLR (P > .05). The effect of time was significant for FABQ (P = .02) and RMDQ (P = .01); however, the effect of group was significant for the FABQ after intervention (P = .04). CONCLUSIONS: Stabilization exercise associated with CBT is more effective than SE alone in improving fear avoidance belief and in increasing the thickness of the TrA muscle during ADIM task.

Intrasession Real-time Ultrasonography Feedback Improves the Quality of Transverse Abdominis Contraction.

OBJECTIVE: The purpose of this study was to compare changes in thickness of the transverse abdominis during performance of the hollowing exercise guided by feedback using ultrasonography images together with verbal guidance and using verbal guidance alone. We also determined the minimal detectable change and agreement between normalized pressures and muscle thickness. METHODS: Twenty participants without lumbar pain performed the hollowing exercises with or without ultrasonography feedback: 7 men and 13 women, mean (SD) age = 25 (5) years, height = 166 (10) cm, body mass = 64 (6) kg, body mass index = 22.2 (5.8) kg/m2. The thickness of the transverse abdominis was quantified during the exercise using musculoskeletal ultrasonography. Basal and 3 repetitions guided by an evaluator were performed. Pressure was determined using a lumbar cushion. Data were compared with a mixed-model analysis of variance and Bonferroni post hoc test (P < .05). Minimal detectable changes were identified and Bland-Altman analysis performed considering normalized thickness and pressure. RESULTS: Ultrasonography feedback resulted in larger thickness changes (P < .05). The lowest minimal detectable changes were achieved using ultrasonography feedback. Nonagreement was found between normalized thickness and pressure. CONCLUSION: Contraction of the transverse abdominis is improved using real-time ultrasonography together with verbal feedback. Low changes in muscle contraction estimated by thickness showed nonagreement with a pressure cushion.

Intrarater Reliability of Shear Wave Elastography for the Quantification of Lateral Abdominal Muscle Elasticity in Idiopathic Scoliosis Patients.

OBJECTIVE: To date, studies evaluating the reliability of shear wave elastography (SWE) measures of the lateral abdominal muscles (LAMs) in adolescent patients with idiopathic scoliosis (AIS) have never been performed. The aim of the study was to assess the intrarater reliability of SWE and thickness of the LAMs at rest and during isometric contraction (10% of maximal voluntary contraction). METHODS: This was a single-group, repeated-measures intrarater reliability study. Twenty-four patients with AIS between ages 10 and 17 years took part in the study. Two and 3 repeated SWE measurements were recorded in the supine resting position and during isometric contraction, respectively. Two sessions were performed with a 7-day interval. RESULTS: By using the mean of 2 measures in the supine, resting position, intraexaminer reliability point estimates (intraclass correlation coefficient [ICC]3.2) ranged from 0.75 to 0.84 for external oblique, internal oblique, and transversus abdominis muscles. During the isometric contraction, the ICC3.3 results ranged from 0.70 to 0.83. The ICC results for muscle thicknesses in both conditions ranged from 0.89 to 0.96. CONCLUSION: Measurements of LAM elasticity are reliable in patients with AIS. The superficial fat layer did not influence the measurement error between 2 sets of measurements in the examined adolescent population. The images extracted from SWE can successfully be used to assess LAM thicknesses with high reliability.

The Effect of Respiratory Phase on Abdominal Muscle Activity During Stable and Unstable Sitting Positions in Individuals With and Without Chronic Low Back Pain.

OBJECTIVE: The aim was to assess the abdominal muscle activities during inspiration and expiration at different sitting positions in individuals with and without chronic low back pain (CLBP). METHODS: This study was conducted on 36 participants (18 with CLBP and 18 healthy controls). Ultrasound imaging was used to assess thickness changes of the transverse abdominis, internal oblique, rectus abdominis, and external oblique muscles. Muscle thickness was measured during inspiration and expiration under 3 different stability levels: sitting on a chair, sitting on a gym ball, and sitting on a gym ball with lifting the left foot. The muscle thickness measured in these positions was normalized to the actual muscle thickness at rest in supine lying and presented as a percentage of thickness change. RESULTS: Both groups displayed greater abdominal muscle activities as the stability of the surface decreased during both respiratory phases. However, compared with the healthy controls, the CLBP group showed smaller muscle thickness changes in all abdominal muscles, except the external oblique, in both respiration phases while sitting on a gym ball with lifting the left foot. The CLBP group displayed overactivity of the rectus abdominis muscle relative to the healthy controls while sitting on a chair in both respiratory phases. CONCLUSION: The findings of the study indicate that as the stability of the support surface decreases, individuals with CLBP had more difficulty activating all abdominal muscles in a similar manner compared to healthy controls in both respiratory phases, which might affect both respiration and postural stability.

The Effects of Thrust Joint Manipulation on the Resting and Contraction Thickness of Transversus Abdominis in Patients With Low Back Pain: A Randomized Control Trial.

OBJECTIVE: To investigate the immediate changes in resting and contracted thickness of the transversus abdominis (TrA) muscle after application of thrust joint manipulation (TJM) vs sham manipulation in participants with low back pain. METHODS: A pretest-posttest randomized controlled trial design was performed. Consecutive subjects satisfying eligibility criteria completed patient-report outcome baseline measures, pretreatment rehabilitative ultrasound imaging (RUSI) measurements, followed by the randomly assigned intervention then, post-treatment RUSI measurements, and post-treatment & final patient-reported outcome measures. To compare the outcomes of TJM and sham manipulation on the TrA muscle thickness, a 2-by-2 analysis of variance (treatment [TJM and sham manipulation]) by time (pretreatment and post-treatment) was completed for both the TrA muscle thickness at rest and muscle thickness during contraction. Descriptive statistics including independent-sample t tests for continuous variables and χ2 tests for categorical variables were used to analyze differences in patient-reported outcome measures between groups. RESULTS: Sixty-seven eligible participants agreed to participate. No significant interactions were identified for either muscle thickness at rest or contraction. CONCLUSION: This study did not support the hypothesis that manipulation would result in greater changes in TrA thickness at rest or during contraction in participants with low back pain. Based on prior research that identified subgroups of participants likely to respond to manipulation, future research should include participants more likely to respond favorably to TJM. This study was a priori registered with clinicaltrails.gov (NCT02558855).

A therapeutic effect for males with spinal cord injury using abdominal functional electrical stimulation for sexual functioning.

INTRODUCTION: Sexual functioning is a high priority for people with a spinal cord injury (SCI) yet this area has received little attention. Two SCI case reports are presented which suggests there may be greater potential for the recovery of sexual functioning than previously recognised. CASE PRESENTATION: A 74-year-old SCI male (AIS D, C5/C6) and a 36-year-old SCI male (AIS A, T4/T5) were treated for neurogenic bowel using 6 weeks of abdominal FES (ABFES) (40 Hz, 300 µ pulse width (current typically 30-60 MA) simultaneously delivered (8 s contraction with 2 s ramps and 3 s off period) from both channels). The 74-year-old AIS D, C5/C6 participant reported improved strength and duration of erectile function after using ABFES for 3 weeks. The 36-year-old AIS A, T4/T5 participant reported improvements in ejaculatory function and urine flow. Both reported a reduction in time required for bowel management. DISCUSSION: The findings could be attributed to an improved vascularisation of the abdominal area, an improved body image and self-esteem, direct innervation of nerves involved in parasympathetic pathways or innervation of the T11/T1 area implicated in the alternative psychogenic pathway. Both participants reported they had not used ABFES during sexual activity suggesting a therapeutic effect from the treatment.