The abdominal drawing-in manoeuvre for detecting activity in the deep abdominal muscles: is this clinical tool reliable and valid?

Clinically assessed lumbopelvic sensorimotor control tests in low back pain: are they actually valid? A systematic review according to COSMIN guidelines

BACKGROUND

Impairments in lumbopelvic sensorimotor control (SMC) are thought to be one of the underlying mechanisms for the recurrence and persistence of low back pain (LBP). As such, lumbopelvic SMC tests are frequently included in the clinical examination of patients with LBP.

OBJECTIVE

To evaluate convergent and known-groups validity of clinically assessed lumbopelvic SMC tests in patients with LBP according to COSMIN guidelines.

DESIGN

Systematic review METHODS: Five electronic databases were searched until December 2023. Studies examining convergent or known-groups validity of lumbopelvic SMC tests assessed via inspection or palpation in patients with LBP were included. Known-groups validity had to be assessed between patients with LBP and pain-free persons. Two independent researchers appraised risk of bias and quality of evidence (QoE) using the COSMIN Risk of Bias checklist and modified GRADE approach, respectively. Results for known-groups validity were reported separately for single tests and test-clusters.

RESULTS

Twelve studies (946 participants) were included. Three studies investigated convergent validity of three single tests. Regarding known-groups validity, six studies evaluated six single tests and four studies investigated two test-clusters. For only one test, both convergent and known-groups were assessed. The QoE for tests showing sufficient convergent or known-groups validity was (very) low, whereas QoE was moderate for single tests or test-clusters with insufficient known-groups validity.

CONCLUSION

All clinically assessed lumbopelvic SMC tests with sufficient convergent or known-groups validity had (very) low QoE. Therefore, test outcomes should be interpreted cautiously and strong reliance on these outcomes for clinical decision-making can currently not be recommended.

Diaphragmatic breathing combined with abdominal drawing-in maneuver for walking function in post-stroke patients: a randomized controlled study protocol

BACKGROUND

Patients with stroke frequently experience walking dysfunction. Core training can help improve balance and walking function in patients with stroke. However, core training movements in clinical practice are numerous and differently targeted. Therefore, this study will investigate the improvement of walking function in patients with combined diaphragmatic breathing maneuver (DBM) and draw-in breathing technique (ADIM) training.

METHODS

This single-blind, randomized controlled preliminary will analyze the viability of DBM combined ADIM training versus routine rehabilitation therapy in patients with stroke with early to mid-stroke. Patients will be randomly assigned to either the DBM and ADIM training or the routine rehabilitation training. We will recruit 42 stroke inpatients from the Second Rehabilitation Hospital of Shanghai who meet the trial criteria and measure the balance and walking functions and improvement of that after 4 weeks of intervention. The primary outcome is the 10 m maximum walking test (10MWT). The secondary outcomes indices include the limits of stability test (LOS), Berg balance scale test (BBS), Functional Ambulation Categories test (FAC), Timed Up and Go test (TUG), trunk impairment scale test (TIS), ultrasound indicators of the diaphragm and transversus abdominis (UI), rhythmic weight shift test (RWS), walk across test (WA), Fugl-Meyer assessment of lower extremity (FMA-LE), and Barthel index of ADL test.

DISCUSSION

The primary objective of this project was to investigate the effects of DBM combined with ADIM on balance capacity and walking function for patients with early to mid-stroke. The outcomes of this study will hold significant implications for future clinical applications in rehabilitation.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR), ID: ChiCTR2100054897. Registered on 28 December 2021.

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.

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.

Comparison of Abdominal Muscle Thickness between the Abdominal Draw-in Maneuver and Maximum Abdominal Contraction Maneuver

All abdominal muscles, including the transverse abdominis (TrA), should be modulated to improve core stability. This study aimed to investigate easier and more effective core exercise methods by comparing thickness changes in the TrA, internal oblique (IO), external oblique (EO), and rectus abdominis (RA) muscles during the abdominal draw-in maneuver (ADIM) and maximum abdominal contraction maneuver (MACM). Thirty healthy subjects who participated in this study underwent ADIM and MACM three times in random order. We measured the abdominal muscle thickness during ADIM and MACM using ultrasonography and compared the changes in the thickness of TrA, IO, EO, and RA muscles using a paired t-test. Significant differences were observed in the thicknesses of all the abdominal muscles between the ADIM and MACM groups (p < 0.05). The MACM immediately increased the thickness of the TrA (p < 0.001, effect size (ES) = 0.931), IO (p = 0.001, ES = 0.761), EO (p = 0.008, ES = 0.415), and RA (p < 0.001, ES = 0.767) muscles. These results suggest that MACM is useful for immediately increasing the thickness of TrA, IO, EO, and RA muscles and may contribute to the clinical effect of simultaneous contractions on the changes in abdominal muscle thickness.

The Role of Rehabilitative Ultrasound Imaging Technique in the Lumbopelvic Region as a Diagnosis and Treatment Tool in Physiotherapy: Systematic Review, Meta-Analysis and Meta-Regression

Rehabilitative ultrasound imaging (RUSI) technique seems to be a valid and reliable tool for diagnosis and treatment in physiotherapy and has been widely studied in the lumbopelvic region the last three decades. The aims for this utility in clinical settings must be review through a systematic review, meta-analysis and meta-regression. A systematic review was designed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines with PROSPERO registration and per review in all phases of the process using COVIDENCE, analysis of risk of bias and meta-analysis using REVMAN, and meta-regression calculation using STATA. Database screening provided 6544 references, out of which 321 reported narrative synthesis, and 21 reported quantitative synthesis, while only 7 of them provided comparable data to meta-analyze the variables pain and muscle thickness. In most cases, the forest plots showed considerable I2 heterogeneity indexes for multifidus muscle thickness (I2 = 95%), low back pain (I2 = 92%) and abdominal pain (I2 = 95%), not important for transversus abdominis muscle thickness (I2 = 22%), significant heterogenity (I2 = 69%) depending on the subgroup and not important internal oblique muscle thickness (I2 = 0%) and external oblique muscle thickness (I2 = 0%). Meta-regression did not provide significant data for the correlations between the variables analyzed and the intervention, age, and BMI (Body Mass Index). This review reveals that RUSI could contribute to a high reliability of the measurements in the lumbopelvic region with validity and reliability for the assessments, as well as showing promising results for diagnosis and intervention assessment in physiotherapy compared to the traditional model, allowing for future lines of research in this area.

Effects of stabilization exercises on disability, pain, and core stability in patients with non-specific low back pain: A randomized controlled trial

BACKGROUND

Many studies have emphasized the importance of stabilization exercises (SE) for the management of non-specific low back pain (NSLBP), yet there is no study assessing all aspects of core stability in comparing SE and other exercises.

OBJECTIVE

To investigate the effects of SE on pain and core stability by using core stability tests that focus on all aspects of core stability in patients with NSLBP.

METHODS

Thirty-seven individuals with chronic NSLBP were randomly divided into two groups as SE and conventional exercises (CE). Both groups underwent the progressive exercise program three days per week for six weeks. The assessments were conducted before and after the exercise programs. The outcome measures included pain, disability, trunk strength, trunk flexor, extensor and lateral flexor endurance, function, flexibility, and motor control during eyes open/closed.

RESULTS

All assessment parameters except motor control during eyes open improved after SE (p < 0.05). Also, all assessment parameters except motor control during eyes open/closed and lateral trunk endurance improved after CE (p < 0.05). When comparing groups for gain scores, there were more significant improvements in pain during activity, endurance and function after SE (p < 0.05).

CONCLUSIONS

SE is more effective than CE in reducing pain during activity and improving core stability regarding functionality and endurance.

Are There Differences in Abdominal Muscle Function in Female Singers With and Without Voice Disorders? - An Observational Study

OBJECTIVES

The purpose of this study was to determine the motor function of the abdominal muscles in singers with and without functional voice disorders and to examine them for possible differences. Additionally, the breathing behaviour and posture control was investigated.

STUDY DESIGN

Observational study.

METHODS

Female subjects (n = 20) with differing levels of professional competence were used to provide the data for analysis. By using the Singing Voice Handicap Index (SVHI) the grade of dysphonia could be measured, and the subjects were organized in groups. The change of muscle thickness of the M. transversus abdominis (TVA) and the M. obliquus internus abdominis (OIA) during different singing tasks was measured by using ultrasound. The subjects were then asked to perform the Abdominal Hollowing Test (AHT) with the STABILIZER. Finally, the subjects were all filmed while singing. The videos recordings of the singing sessions were analysed by an independent clinical expert regarding breathing and secondary motor activities (SMA). For the statistical analysis, the Mann-Whitney-U Test and the Chi-Square-Test was mainly used.

RESULTS

The results showed a significantly thinner TVA in the group with dysphonia in comparison to the group without dysphonia. Ultrasound measurements showed significantly higher changes of muscle thickness of the TVA during singing tasks in the group with dysphonia. Regarding the AHT there was a significant difference between the two groups. The group with dysphonia was not able to increase the pressure by 15mmHg. Furthermore, the healthy subjects demonstrated abdominal breathing, while the group with dysphonia present with thoracic breathing. Additionally, it was noted that the subjects with dysphonia showed a higher level of associated movements especially at and/or on the lumbar spine, cervical spine and the left arm and shoulder.

CONCLUSION

Differences in TVA-recruitment, breathing behaviour and secondary motor activities while singing were found. This study sparks new ideas for neuromusculoskeletal assessments and therapy.

Reproducibility and Concurrent Validity of Manual Palpation with Rehabilitative Ultrasound Imaging for Assessing Deep Abdominal Muscle Activity: Analysis with Preferential Ratios

The abdominal drawing-in maneuver (ADIM) is a clinical tool used for identifying preferential activity of deep abdominal muscles. However, concurrent validity and reproducibility of palpation during the ADIM has not been formally investigated. The aims of this study were (1) to assess intra- and interrater reliability of manual palpation during the ADIM, and (2) to determine the concurrent validity of manual palpation during the ADIM by calculating preferential activation ratio cut-off as assessed with ultrasound imaging (RUSI). Thirty-two subjects (n = 16 patients with nonspecific low back pain and 16 comparable healthy individuals) performed the ADIM in a supine hook-lying position. Two experienced assessors evaluated the presence or absence of preferential contraction of the deep abdominal muscles by palpation during the ADIM on 2 different days. Intrarater (test-retest) and interrater reliability of palpation were calculated using Cohen's kappa coefficients. Muscle thickness of the transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) muscles at rest and during the ADIM were also measured. TrA-Contraction Ratio (TrA-CR), TrA-Preferential Activation Ratio (TrA-PAR), and Modified-TrA-PR (M-TrA-PAR) were calculated. The concurrent validity of manual palpation was determined using the correlation between manual palpation and imaging and by calculating ROC curve (operating characteristics curve), Youden index, and sensitivity and specificity. Intra- and interrater reliability of manual palpation during the ADIM was excellent (k: 0.82-1.00) and good to excellent (k: 0.71-1.00), respectively. Interrater reliability for muscle thickness ranged from good to excellent (ICC3,1 0.79-0.91). Manual palpation and TrA ratio showed low to moderate correlations (r: 0.36-0.60). When evaluating the diagnostic accuracy of manual palpation, the best predictive model (ROC value: 0.89; p < 0.001) for correct a preferential contraction of TrA was obtained when the M-TrA-PAR was ≥0.08 (sensitivity: 0.95-1.00; specificity: 0.62). Good to excellent intra- and interrater reliability of manual palpation was found during the ADIM in both patients and healthy groups. Manual palpation showed concurrent validity for identifying the preferential activity of the TrA muscle supporting its use in clinical practice.

Gliding performance is affected by cranial movement of abdominal organs

Swimming is an extremely popular sport around the world. The streamlined body position is a crucial and foundational position for swimmers. Since the density of lungs is low, the center of buoyancy is always on the cranial side and the center of gravity is always on the caudal side. It has been reported that the greater the distance between the centers of buoyancy and gravity, the swimmer’s legs will sink more. This is disadvantageous to swimming performance. However, the way to reduce the distance between the centers of buoyancy and gravity is yet to be elucidated. Here we show that swimmers with high gliding performance exhibit different abdominal cavity shapes in the streamlined body position, which causes cranial movement of the abdominal organs. This movement can reduce the distance between the centers of buoyancy and gravity, prevent the legs from sinking, and have a positive effect on gliding performance.

Prefabricated foot orthoses compared to a placebo intervention for the treatment of chronic nonspecific low back pain: a study protocol for a randomised controlled trial

BACKGROUND

Prefabricated foot orthoses are used to treat chronic nonspecific low back pain, however their effectiveness and potential mechanism of action is unclear. The primary aims of the study are to investigate the effectiveness of prefabricated foot orthotic devices for reducing pain and improving function in people with chronic nonspecific low back pain over 52 weeks.

METHODS

This study is a participant and assessor blinded, parallel-group, superiority randomised (1:1) controlled trial. The study will recruit 60 participants aged 18 to 65 years with chronic nonspecific low back pain. Participants will undergo randomisation to a control group (The Back Book) or an intervention group (prefabricated foot orthoses and The Back Book). The primary outcome measures will be change in pain and function from baseline to 12 (primary time point), 26, and 52 weeks. Secondary outcome measures include: gluteus medius muscle activity and transversus abdominis muscle thickness from baseline to 12 weeks, physical activity over 12, 26, and 52 weeks, and correlation between foot type and change in measures of pain and function. Number of hours per day and week that the prefabricated orthoses are worn, as well as, adverse events will be self-reported by participants. Data will be analysed using the intention-to-treat principle.

DISCUSSION

This trial will primarily evaluate the effectiveness of prefabricated foot orthotic devices for reducing pain and improving function in people with chronic nonspecific low back pain over 52 weeks. It is expected that this study will provide clinicians and researchers with an understanding of the role that prefabricated foot orthoses may have in the treatment of chronic nonspecific low back pain and a potential mechanism of action, and whether foot type influences the outcome.

TRIAL REGISTRATION

ACTRN12618001298202.

Not only static: Stabilization manoeuvres in dynamic exercises - A pilot study

This study examined characteristics of trunk muscles electrical activity in young adults performed in the course of static and dynamic trunk muscles strengthening exercises using different lumbar spine stabilization manoeuvres. Twenty young adults (Mage = 25.5 SD = 2.91) participated in this study. Of the 20, 11 subjects (5 males and 6 females) reported no history of pain, 9 subjects (5 males and 4 females) reported lower back pain (LBP) within the last three months. Subjects performed lumbar spine stabilization manoeuvres (abdominal bracing (AB) and abdominal hollowing (AH)) with static and dynamic abdominal muscles strengthening exercises (i.e., plank, side-bridges, and curl-ups). Noraxon Telemyo twelve channel electromyography device (Noraxon USA, Inc.) was used to record EMG data from rectus abdominal muscle (RA), external oblique muscles (EO), internal oblique muscles (IO), and erector spine muscles (ES). In static exercises such as side-bridge exercise, significantly higher RA muscle electrical activity was recorded with AB manoeuvre compared to AH manoeuvre both on the right side and left side respectively (Z = -2.17; p = 0.03; Z = 3.40; p = 0.001). In dynamic exercises such as curl-up exercise, during the lifting phase, median value of RA muscle activity with AB was significantly higher than with AH (Z = -2.315; p = 0.021). Median value of IO muscles activity with AH was significantly higher than with AB (Z = -3.230; p = 0.001). Our findings indicated that although surface muscles are more activated with AB manoeuvre exercises, deep abdominal muscles are more activated in exercises with AH manoeuvre. These findings can help practitioners design interventions to integrate AH manoeuvre for benefiting persons with lumbar instability.

Psychometric Properties of the Deep Muscle Contraction Scale for Assessment of the Drawing-in Maneuver in Patients With Chronic Nonspecific Low Back Pain

Study Design A prospective cohort study. Background Motor control dysfunctions have been commonly reported in patients with chronic nonspecific low back pain (LBP). Physical therapists need clinical tools with adequate psychometric properties to assess such patients in clinical practice. The deep muscle contraction (DMC) scale is a clinical rating scale for assessing patients' ability to voluntarily contract deep abdominal muscles. Objectives To investigate the intrarater reliability, floor and ceiling effects, internal and external responsiveness, and correlation analysis (with ultrasound measures) of the DMC scale in patients with chronic nonspecific LBP undergoing a lumbar stabilization exercise program. Methods Sixty-two patients with chronic nonspecific LBP were included. At baseline, self-report questionnaires were administered to patients and a trained assessor evaluated abdominal muscle recruitment with the DMC scale and ultrasound imaging. Four ratios of the change in abdominal muscle thickness between the resting and contracted states were calculated through the ultrasound measures. After 1 week, the same ultrasound measures and DMC scale were collected again for the reliability analysis. The proportions of patients with the lowest and highest scores on the DMC scale were calculated to investigate floor and ceiling effects. All patients underwent a lumbar stabilization program, administered twice a week for 8 weeks. After the treatment period, all measures were collected again, with the addition of the global perceived effect scale, to assess the internal and external responsiveness of the measures. Correlation coefficients between ultrasound ratios and DMC scale total and subscale scores were also calculated. Results The intrarater reliability of the DMC scale and the 4 ratios of abdominal muscle thickness varied from moderate to excellent. The DMC scale showed no floor or ceiling effects. Results for internal responsiveness of the DMC scale showed large effect sizes (2.26; 84% confidence interval [CI]: 2.06, 2.45), whereas the external responsiveness was below the proposed threshold (area under the curve = 0.54; 95% CI: 0.39, 0.68). Fair and significant correlations between some ultrasound ratios and DMC subscales were found. Conclusion The DMC scale was demonstrated to be a reliable tool, with no ceiling and floor effects, and to detect change in the ability to contract the deep abdominal muscles after a lumbar stabilization exercise program, but with low accuracy for estimating patient-perceived clinical outcome. J Orthop Sports Phys Ther 2017;47(6):432-441. doi:10.2519/jospt.2017.7140.