The use of ultrasound imaging of the abdominal drawing-in maneuver in subjects with low back pain

The effects of running in place in a limited area with abdominal drawing-in maneuvers on abdominal muscle thickness in chronic low back pain patients

BACKGROUND

Based on previous studies indicating that core stabilization exercises accompanied by abdominal drawing-in maneuvers increase the thickness of the transversus abdominis muscle.

OBJECTIVE

The purpose of this study was to compare the measurements of abdominal muscle thicknesses during running in place in a limited area with the abdominal drawing-in maneuver.

METHODS

The study classified the subjects into two experimental groups: the training group (M = 2, F = 13), and the control group (M = 2, F = 13). The training group performed three sets of running in place in a limited area with abdominal drawing-in maneuvers each time, three times a week for six weeks. The abdominal muscle thicknesses of the subjects were measured using ultrasonography.

RESULTS

Comparing the training group's abdominal muscle thickness before and after this study, there was a statistical significance in all of the external obliquus abdominis, the internal obliquus abdominis, and the transversus abdominis. In particular, thicknesses of external obliquus abdominis and internal obliquus increased remarkably.

CONCLUSIONS

Running in place in a limited area accompanied by abdominal drawing-in maneuvers increased the thickness of the deep abdominal muscles that are the basis of trunk stabilization.

The Effect of Distractive Function on Volitional Preemptive Abdominal Contraction During a Loaded Forward Reach in Normal Subjects

BACKGROUND

Volitional preemptive abdominal contraction (VPAC) is used to protect the spine and prevent injury. No published studies to data have examined the effect of distraction on VPAC use during function.

OBJECTIVE

To examine the effect of an auditory distraction ("Stroop task") on healthy subjects' ability to sustain VPAC by use of the abdominal drawing-in maneuver during loaded forward reach.

DESIGN

Within-subjects, repeated-measure cohort design.

SETTING

Clinical laboratory setting.

PARTICIPANTS

Convenience sample of 42 healthy individuals (ages 20-57 years).

METHODS

Transversus abdominis (TrA) thickness was measured with M-mode ultrasound imaging. Each subject performed Stroop versus no Stroop during 4 conditions: (1) without VPAC, quiet standing; (2) with VPAC, quiet standing; (3) without VPAC, forward reach; and (4) with VPAC, forward reach. An investigator blinded to the conditions measured the first 10 subjects to establish intratester reliability of probe/transducer placement and TrA measurement.

DATA REDUCTION

TrA thickness (mm) change represented VPAC performance. A single investigator measured onscreen TrA thickness twice at each second from second-6 through -10 on a recorded ultrasound imaging sequence.

RESULTS

A 2 (Stroop) × 4 (Activity) repeated-measures analysis of variance found no significant Stroop × Activity interaction [F(3, 93) = 0.345, P = .793] and no main effect for Stroop [F (1,31) = 1.324, P = .259] but found a significant main effect for activity [F (3,93) = 17.729, P < .001]. Tukey post-hoc pairwise comparisons demonstrated significant differences between VPAC versus no-VPAC conditions, except between quiet standing/yes-VPAC and loaded forward reach/no-VPAC conditions (P = .051). The interclass correlation coefficient (3,2) for probe/transducer placement reliability was 0.87, 0.91, 0.92, and 0.93 for conditions 1-4, respectively. The interclass correlation coefficient (3,2) for TrA measurement reliability was 0.96, 0.99, 0.99, and 0.99 for conditions 1-4, respectively.

CONCLUSION

A distracting executive function (Stroop task) did not produce a significant negative impact on normal individuals' ability to sustain a VPAC during quiet standing or loaded forward reach activities.

LEVEL OF EVIDENCE

II.

The Effect of Current Low Back Pain on Volitional Preemptive Abdominal Activation During a Loaded Forward Reach Activity

BACKGROUND

A volitional preemptive abdominal contraction (VPAC) supports trunk stability during functional activity. Pain-free individuals can sustain VPAC during function, but such has not been reported for individuals with current low back pain (cLBP).

OBJECTIVE

To examine whether cLBP affects VPAC performance during a loaded forward reach (LFR) task.

DESIGN

Observational crossover study.

SETTING

Laboratory.

PARTICIPANTS

A total of 18 controls and 17 subjects with cLBP with pain ratings of 1/10 to 4/10 on a visual analog scale.

INTERVENTIONS

Transverse abdominis (TrA) thickness measurements were recorded by blinded researchers from M-mode ultrasound imaging during 4 conditions: (1) quiet standing without abdominal drawing-in maneuver (ADIM); (2) quiet standing with ADIM; (3) LFR without ADIM; and (4) LFR with ADIM. A physical therapist with 29 years of experience collected historical and examination data.

MAIN OUTCOME MEASURES

TrA muscle thickness (mm).

RESULTS

A 2 (group) × 2 (contraction) × 2 (reach) analysis of variance demonstrated a significant group × contraction interaction (F [1, 31] = 4.499, P = .04) where ADIM produced greater TrA thickness increases in PLBP subjects (2.18 mm) versus controls (1.36 mm). We observed a significant main effect for reach (F [1, 31] = 14.989, P < .001), where LFR activity produced a greater TrA thickness (6.15 ± 2.48 mm) versus quiet standing (5.30 ± 2.12 mm).

CONCLUSIONS

Subjects with cLBP demonstrated a greater increase in TrA activation during ADIM versus controls.

Ultrasound Measurement of Abdominal Muscle Thickness With and Without Transducer Fixation During Standing Postural Tasks in Participants With and Without Chronic Low Back Pain: Intrasession and Intersession Reliability

BACKGROUND

Ultrasound (US) imaging can be used for the measurement of trunk muscle activity. The displacements of US transducer, especially during more dynamic situations, however, may disturb the measurement results. To control this variable, some studies have used transducer fixator (TF), but no study evaluated the effect of using TF on US reliability in dynamic situations. The present study discriminated this issue.

OBJECTIVE

To investigate the intrasession and intersession reliability of lateral abdominal muscle thickness measurement in dynamic standing postural tasks by using US with and without TF in participants with and without chronic low back pain (CLBP).

DESIGN

An intersession and intrasession reliability study.

SETTING

Biomechanics laboratory, Neuromuscular Rehabilitation Research Center, Semnan University of Medical Sciences, Semnan, Iran.

PARTICIPANTS

Twenty-three patients with CLBP and 23 healthy matched individuals.

METHODS

Abdominal muscle thickness of all the subjects was evaluated with use of US imaging with the patient in the supine position and double-leg stance at different levels of platform stability of BBS (static, levels 6 and 3), with and without using TF. Intraclass correlation coefficients (ICCs), standard errors of measurement, minimal metrically detectable changes, and coefficients of variation were calculated to determine intersession and intrasession reliability of muscle activity measure.

MAIN OUTCOME MEASUREMENTS

Lateral abdominal muscle thickness.

RESULTS

The intersession ICCs in the conditions with TF ranged from 0.93 to 0.98 and 0.97 to 0.99 in CLBP and healthy individuals, respectively. The intersession ICCs in the conditions without TF ranged from 0.67 to 0.79 and 0.7 to 0.86 in CLBP and healthy groups, respectively. In addition, smaller standard errors of measurement and minimal metrically detectable change values were observed with US measurement in both the groups when TF was used.

CONCLUSION

US imaging appears to have acceptable reliability for the assessment of abdominal muscle thickness during dynamic standing tasks in individuals with and without CLBP. The use of TF results in greater levels of reliability during US measurement of abdominal muscle.

LEVEL OF EVIDENCE

III.

The comparison of abdominal muscle activation on unstable surface according to the different trunk stability exercises

[Purpose] This study aimed to determine the effect of abdominal muscle activities and the activation ratio related to trunk stabilization to compare the effects between the abdominal drawing-in maneuver and lumbar stabilization exercises on an unstable base of support. [Subjects and Methods] Study subjects were 20 male and 10 female adults in their 20s without lumbar pain, who were equally and randomly assigned to either the abdominal drawing-in maneuver group and the lumbar stabilization exercise group. Abdominal muscle activation and ratio was measured using a wireless TeleMyo DTS during right leg raise exercises while sitting on a Swiss ball. [Results] Differences in rectus abdominis, external oblique abdominis, and internal oblique abdominis muscle activation were observed before and after treatment. Significant differences were observed between the groups in the muscle activation of the external oblique abdominis and internal oblique abdominis, and the muscle activation ratio of external oblique abdominis/rectus abdominis and internal oblique abdominis/rectus abdominis. [Conclusion] Consequently trunk stability exercise enhances internal oblique abdominis activity and increases trunk stabilization. In addition, the abdominal drawing-in maneuver facilitates the deep muscle more than LSE in abdominal muscle. Therefore, abdominal drawing-in maneuver is more effective than lumbar stabilization exercises in facilitating trunk stabilization.

Comparison of changes in the mobility of the pelvic floor muscle on during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction

[Purpose] The purpose of this study was to compare changes in the mobility of the pelvic floor muscle during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction. [Subjects] Thirty healthy adults participated in this study (15 men and 15 women). [Methods] All participants performed a bridge exercise and abdominal curl-up during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction. Pelvic floor mobility was evaluated as the distance from the bladder base using ultrasound. [Results] According to exercise method, bridge exercise and abdominal curl-ups led to significantly different pelvic floor mobility. The pelvic floor muscle was elevated during the abdominal drawing-in maneuver and descended during maximal expiration. Finally, pelvic floor muscle mobility was greater during abdominal curl-up than during the bridge exercise. [Conclusion] According to these results, the abdominal drawing-in maneuver induced pelvic floor muscle contraction, and pelvic floor muscle contraction was greater during the abdominal curl-up than during the bridge exercise.

Does core stability exercise improve lumbopelvic stability (through endurance tests) more than general exercise in chronic low back pain? A quasi-randomized controlled trial

INTRODUCTION

The aim was to compare core stability and general exercises (GEs) in chronic low back pain (LBP) patients based on lumbopelvic stability (LPS) assessment through three endurance core stability tests. There is a controversy about preference of core stability exercise (CSE) over other types of exercise for chronic LBP. Studies which have compared these exercises used other outcomes than those related to LPS. As it is claimed that CSE enhances back stability, endurance tests for LPS were used.

MATERIALS AND METHODS

A 16-session CSE program and a GE program with the same duration were conducted for two groups of participants. Frequency of interventions for both groups was three times a week. Forty-three people (aged 18-60 years) with chronic non-specific LBP were alternately allocated to core stability (n = 22) or GE group (n = 21) when admitted. The primary outcomes were three endurance core stability tests including: (1) trunk flexor; (2) trunk extensor; and (3) side bridge tests. Secondary outcomes were disability and pain. Measurements were taken at baseline and the end of the intervention.

RESULTS

After the intervention, test times increased and disability and pain decreased within groups. There was no significant difference between two groups in increasing test times (p = 0.23 to p = 0.36) or decreasing disability (p = 0.16) and pain (p = 0.73).

CONCLUSIONS

CSE is not more effective than GE for improving endurance core stability tests and reducing disability and pain in chronic non-specific LBP patients.

Ultrasound measurement of deep and superficial abdominal muscles thickness during standing postural tasks in participants with and without chronic low back pain

BACKGROUND

Activity of deep abdominal muscles increases the lumbar stability. Majority of previous studies indicated abdominal muscle activity dysfunction during static activity in patients with low back pain (LBP). However, the number of studies that evaluated deep abdominal muscle activity in dynamic standing activities in patients is limited, while this assessment provides better understanding of pain behavior during these activities.

OBJECTIVE

Investigation of superficial and deep abdominal muscles activity in participants with chronic LBP as compared to healthy individuals during standing tasks.

DESIGN

Case control study.

METHODS

Ultrasound imaging was used to measure the thickness of transverse abdominis (TrA), internal oblique (IO) and external oblique (EO) muscles in female participants with (N = 45) and without chronic LBP (CLBP) (N = 45) during tests. The Biodex Balance System was used to provide standing tasks. The thickness of each muscle in a standing task was normalized to actual thickness at rest in the supine lying position to estimate its activity.

RESULTS

The results indicate increases in thickness of all muscles in both groups during dynamic as compared to static standing tasks (P < 0.05, ES > 0.5). Lower percentages of thickness change for TrA muscle and higher for EO muscle were found in the patients as compared to healthy individuals during all tests (P < 0.05, ES > 1.28).

CONCLUSIONS

Higher activity of superficial than deep abdominal muscles in patients as compared to healthy individuals during standing tasks indicates motor control dysfunction in patients with CLBP. Standing tasks can discriminate the individuals with and without LBP and can be progressively used in training.

Motor control exercise for chronic non-specific low-back pain

BACKGROUND

Non-specific low back pain (LBP) is a common condition. It is reported to be a major health and socioeconomic problem associated with work absenteeism, disability and high costs for patients and society. Exercise is a modestly effective treatment for chronic LBP. However, current evidence suggests that no single form of exercise is superior to another. Among the most commonly used exercise interventions is motor control exercise (MCE). MCE intervention focuses on the activation of the deep trunk muscles and targets the restoration of control and co-ordination of these muscles, progressing to more complex and functional tasks integrating the activation of deep and global trunk muscles. While there are previous systematic reviews of the effectiveness of MCE, recently published trials justify an updated systematic review.

OBJECTIVES

To evaluate the effectiveness of MCE in patients with chronic non-specific LBP.

SEARCH METHODS

We conducted electronic searches in CENTRAL, MEDLINE, EMBASE, five other databases and two trials registers from their inception up to April 2015. We also performed citation tracking and searched the reference lists of reviews and eligible trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that examined the effectiveness of MCE in patients with chronic non-specific LBP. We included trials comparing MCE with no treatment, another treatment or that added MCE as a supplement to other interventions. Primary outcomes were pain intensity and disability. We considered function, quality of life, return to work or recurrence as secondary outcomes. All outcomes must have been measured with a valid and reliable instrument.

DATA COLLECTION AND ANALYSIS

Two independent review authors screened the search results, assessed risk of bias and extracted the data. A third independent review author resolved any disagreement. We assessed risk of bias using the Cochrane Back and Neck (CBN) Review Group expanded 12-item criteria (Furlan 2009). We extracted mean scores, standard deviations and sample sizes from the included trials, and if this information was not provided we calculated or estimated them using methods recommended in the Cochrane Handbook. We also contacted the authors of the trials for any missing or unclear information. We considered the following time points: short-term (less than three months after randomisation); intermediate (at least three months but less than 12 months after randomisation); and long-term (12 months or more after randomisation) follow-up. We assessed heterogeneity by visual inspection of the forest plots, and by calculating the Chi(2) test and the I(2) statistic. We combined results in a meta-analysis expressed as mean difference (MD) and 95% confidence interval (CI). We assessed the overall quality of the evidence using the GRADE approach.

MAIN RESULTS

We included 29 trials (n = 2431) in this review. The study sample sizes ranged from 20 to 323 participants. We considered a total of 76.6% of the included trials to have a low risk of bias, representing 86% of all participants. There is low to high quality evidence that MCE is not clinically more effective than other exercises for all follow-up periods and outcomes tested. When compared with minimal intervention, there is low to moderate quality evidence that MCE is effective for improving pain at short, intermediate and long-term follow-up with medium effect sizes (long-term, MD -12.97; 95% CI -18.51 to -7.42). There was also a clinically important difference for the outcomes function and global impression of recovery compared with minimal intervention. There is moderate to high quality evidence that there is no clinically important difference between MCE and manual therapy for all follow-up periods and outcomes tested. Finally, there is very low to low quality evidence that MCE is clinically more effective than exercise and electrophysical agents (EPA) for pain, disability, global impression of recovery and quality of life with medium to large effect sizes (pain at short term, MD -30.18; 95% CI -35.32 to -25.05). Minor or no adverse events were reported in the included trials.

AUTHORS' CONCLUSIONS

There is very low to moderate quality evidence that MCE has a clinically important effect compared with a minimal intervention for chronic low back pain. There is very low to low quality evidence that MCE has a clinically important effect compared with exercise plus EPA. There is moderate to high quality evidence that MCE provides similar outcomes to manual therapies and low to moderate quality evidence that it provides similar outcomes to other forms of exercises. Given the evidence that MCE is not superior to other forms of exercise, the choice of exercise for chronic LBP should probably depend on patient or therapist preferences, therapist training, costs and safety.

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

OBJECTIVE

The abdominal drawing-in manoeuvre (ADIM) is a common clinical tool for manually assessing whether a preferential activation of the deep abdominal muscles in patients with low back pain (LBP) is 'correct' or not. The validity and reliability of manual assessment of the ADIM are, however, as yet unknown. This study evaluated the concurrent and discriminative validity and reliability of the manually assessed ADIM.

DESIGN

Single-blinded cross-sectional study.

SETTINGS

General population in Stockholm County, Sweden.

PARTICIPANTS

The study sample comprised 38 participants seeking care for LBP, and 15 healthy subjects.

MEASURES

The manual ADIM was assessed as correct or not following a standard procedure. Ultrasound imaging (USI) was used as the concurrent reference (gold standard) for the manually assessed ADIM by calculating a ratio of the change in muscle thickness between the resting and the contracted states: the correlation between manual test and USI was calculated. Discriminative validity was analysed by calculating sensitivity and specificity. A sample of 24 participants was analysed with κ coefficients for interobserver reliability between two raters.

RESULTS

The concurrent validity between the manual ADIM and the ADIM-USI ratios showed poor correlations (r=0.13-0.40). The discriminative validity of the manually assessed ADIM to predict LBP showed a sensitivity/specificity of 0.30/0.73, while the ADIM-USI ratio to predict LBP showed 0.19/0.87. The interobserver reliability for the manually assessed ADIM revealed substantial agreement: K=0.71, CI (95%) 0.41 to 1.00.

CONCLUSIONS

Although the interobserver reliability of the manually assessed ADIM was high, the concurrent and discriminative validity were both low for examining the preferential activity of the deep abdominal muscles. Neither the manually assessed ADIM nor the ultrasound testing discriminated between participants with LBP and healthy subjects regarding preferential activity of the transversus muscle as this ability/inability was also present in healthy subjects.

Reliability of new software in measuring cervical multifidus diameters and shoulder muscle strength in a synchronized way; an ultrasonographic study

OBJECTIVES:

This study was conducted with the purpose of evaluating the inter-session reliability of new software to measure the diameters of the cervical multifidus muscle (CMM), both at rest and during isometric contractions of the shoulder abductors in subjects with neck pain and in healthy individuals.

METHOD:

In the present study, the reliability of measuring the diameters of the CMM with the Sonosynch software was evaluated by using 24 participants, including 12 subjects with chronic neck pain and 12 healthy individuals. The anterior-posterior diameter (APD) and the lateral diameter (LD) of the CMM were measured in a resting state and then repeated during isometric contraction of the shoulder abductors. Measurements were taken on separate occasions 3 to 7 days apart in order to determine inter-session reliability. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), and smallest detectable difference (SDD) were used to evaluate the relative and absolute reliability, respectively.

RESULTS:

The Sonosynch software has shown to be highly reliable in measuring the diameters of the CMM both in healthy subjects and in those with neck pain. The ICCs 95% CI for APD ranged from 0.84 to 0.94 in subjects with neck pain and from 0.86 to 0.94 in healthy subjects. For LD, the ICC 95% CI ranged from 0.64 to 0.95 in subjects with neck pain and from 0.82 to 0.92 in healthy subjects.

CONCLUSIONS:

Ultrasonographic measurement of the diameters of the CMM using Sonosynch has proved to be reliable especially for APD in healthy subjects as well as subjects with neck pain.

The Immediate Effects on Inter-rectus Distance of Abdominal Crunch and Drawing-in Exercises During Pregnancy and the Postpartum Period

STUDY DESIGN

Longitudinal descriptive exploratory study.

OBJECTIVES

To evaluate in primigravid women the immediate effect of drawing-in and abdominal crunch exercises on inter-rectus distance (IRD), measured at 4 time points during pregnancy and in the postpartum period.

BACKGROUND

There is scant knowledge of the effect of different abdominal exercises on IRD in pregnant and postpartum women.

METHODS

The study included 84 primiparous participants. Ultrasound images were recorded with a 12-MHz linear transducer, at rest and during abdominal drawing-in and abdominal crunch exercises, at 3 locations on the linea alba. The IRD was measured at 4 time points: gestational weeks 35 to 41, 6 to 8 weeks postpartum, 12 to 14 weeks postpartum, and 24 to 26 weeks postpartum. Separate 2-way, repeated-measures analyses of variance (ANOVAs) were performed for each exercise (drawing-in and abdominal crunch) and each measurement location to evaluate the immediate effects of exercises on IRD at each of the 4 time points. Similarly, 2-way ANOVAs were used to contrast the effects of the 2 exercises on IRD.

RESULTS

Performing the drawing-in exercise caused a significant change in width of the IRD at 2 cm below the umbilicus, narrowing the IRD by a mean of 3.8 mm (95% confidence interval [CI]: 1.2, 6.4 mm) at gestational weeks 35 to 41, and widening the IRD by 3.0 mm (95% CI: 1.4, 4.6 mm) at 6 to 8 weeks postpartum, by 1.8 mm (95% CI: 0.6, 3.1 mm) at 12 to 14 weeks postpartum, and by 2.5 mm (95% CI: 1.4, 3.6 mm) at 24 to 26 weeks postpartum (P<.01). Performing the abdominal crunch exercise led to a significant narrowing of the IRD (P<.01) in all 3 locations at all 4 time points, with the exception of 2 cm below the umbilicus at postpartum weeks 24 to 26. The average amount of narrowing varied from 1.6 to 20.9 mm, based on time and location.

CONCLUSION

Overall, there was a contrasting effect of the 2 exercises, with the abdominal crunch exercise consistently producing a significant narrowing of the IRD. In contrast, the drawing-in exercise generally led to a small widening of the IRD.

Reliability of Ultrasound Imaging Measures of Transverse Abdominis and Lumbar Multifidus in Various Positions

OBJECTIVE

To determine the reliability of measurement of muscle activation via ultrasound imaging measures of the transverse abdominis (TrA) and lumbar multifidus (LM) in tabletop, seated, standing, and walking conditions.

DESIGN

Descriptive laboratory study.

SETTING

University research laboratory.

PARTICIPANTS

Sixteen healthy participants (age, 20.4 ± 1.8 years; height, 167.7 ± 9.0 cm; mass, 65.1 ± 10.8 kg).

INTERVENTIONS

None.

MAIN OUTCOME MEASUREMENTS

The activation ratio (AR) of TrA and LM and preferential activation ratio of TrA in tabletop, seated, standing, and walking positions were assessed by the same examiner during 2 ultrasound imaging sessions 24-72 hours apart. Statistical analysis included determination of intraclass correlation coefficients (ICCs) using analysis of variance for each muscle and position between sessions.

RESULTS

Excellent reliability was found in TrA AR between sessions for healthy participants in the tabletop position (ICC3,k = 0.903), and acceptable to excellent reliability was found in seated (ICC3,k = 0.613), standing (ICC3,k = 0.553), and walking (ICC3,k = 0.737) positions. LM AR was fair in the tabletop position for these participants (ICC3,k = 0.264). The preferential activation ratio for healthy participants was substantially reliable in tabletop and seated positions (ICC3,k = 0.668, 0.684) and showed fair reliability for walking (ICC3,k = 0.455).

CONCLUSIONS

Ultrasound imaging is a reliable method of measuring muscle thickness across multiple positions in healthy persons. This measure may be used to compare abdominal muscle thickness across populations or after interventions. LM AR was only found to be reliable in the tabletop position.

Intra-Rater Reliability of Rehabilitative Ultrasound Imaging for Multifidus Muscles Thickness and Cross Section Area in Healthy Subjects

Introduction:

Rehabilitative Ultrasound Imaging (RUSI) must be valuable method for research and rehabilitation. So, the reliability of its measurements must be determined. The purpose of this study was to evaluate the intra-rater reliability of RUSI for measurement of multifidus (MF) muscles cross section areas (CSAs), bladder wall diameter, and thickness of MF muscles between 2 sessions in healthy subjects.

Method:

Fifteen healthy subjects through simple non-probability sampling participated in this single-group repeated-measures reliability study. MF muscles thickness at rest and during contraction, MF muscles CSAs at rest, and bladder diameters at rest and during pelvic floor muscles (PFM) contraction were measured through RUSI. Pearson’s correlation coefficient test was used to determine intra-rater reliability of variables.

Finding:

The results showed that intra-class correlation Coefficient (ICCs) values with 95% confidence interval (CI) and the standard error of the measurement (SEM) were good to excellent agreement for a single investigator between measurement occasions. The intra-rater reliability for the bladder wall displacement was high (ICCs for rest and PFM contraction state: 0.96 and 0.95 respectively), for the MF muscles CSAs at the L4 level was good to high (ICCs 0.75 and 0.91 for right (Rt) and left (Lt) side respectively), and for the thickness of MF muscles at two levels, at rest and during two tasks was moderate to high (ICCs: 0.64 to 0.87).

Conclusion:

The Trans-Abdominal (TA) method of RUSI is a reliable method to quantify the PFM contraction in healthy subjects. Also, the RUSI is a reliable method to measure the MF muscles CSAs, the MF muscles thickness at rest and during functional tasks in healthy subjects.

Comparison of deep and superficial abdominal muscle activity between experienced Pilates and resistance exercise instructors and controls during stabilization exercise

Pilates and resistance exercises are used for lumbar stabilization training. However, it is unclear which exercise is more effective for lumbar stabilization. In our study, we aimed to compare surface muscle activity and deep muscle thickness during relaxation and spinal stabilization exercise in experienced Pilates and resistance exercise instructors. This study is a retrospective case control study set in the Exercise Prescription Laboratory and Sports Medicine Center. The participants included Pilates instructors (mean years of experience, 3.20±1.76; n=10), resistance exercise instructors (mean years of experience, 2.53±0.63; n=10), and controls (n=10). The participants performed 4 different stabilization exercises: abdominal drawing-in maneuver, bridging, roll-up, and one-leg raise. During the stabilization exercises, surface muscle activity was measured with electromyography, whereas deep muscle thickness was measured by ultrasound imaging. During the 4 stabilization exercises, the thickness of the transverse abdominis (TrA) was significantly greater in the Pilates-trained group than the other 2 other groups. The internal oblique (IO) thickness was significantly greater in the Pilates- and resistance-trained group than the control group, during the 4 exercises. However, the surface muscle activities were similar between the groups. Both Pilates and resistance exercise instructors had greater activation of deep muscles, such as the TrA and IO, than the control subjects. Pilates and resistance exercise are both effective for increasing abdominal deep muscle thickness.

Observation of Age-Related Decline in the Performance of the Transverse Abdominis Muscle

BACKGROUND

Previous research has shown that the performance of skeletal muscle declines with advancing age. Coordination of the transverse abdominis (TrA), a deep postural muscle, has been shown to be reduced in persons with low back pain. No previous research has studied the effect of age on the activation on this muscle.

OBJECTIVE

To assess the effect of age on TrA activation in response to rapid arm abduction.

DESIGN

Cross-sectional cohort study.

SETTING

University exercise physiology laboratory.

PARTICIPANTS

A total of 18 adult men (aged 27 ± 7.0 years) for the younger group and 11 older adults (5 men and 6 women, aged 59.6 ± 4.0 years) were recruited for this study.

METHOD

Participants were positioned on a treatment table and performed a series of rapid arm abduction movements with their right arm while the activation of the TrA muscle was recorded using ultrasound imaging. Onset of arm abduction was measured using surface electromyography and synchronized with the ultrasound through the ultrasound unit's electrocardiogram channel. The mean time difference between the 2 events was calculated during post-hoc analysis.

MAIN OUTCOME MEASUREMENTS

A Mann-Whitney test was performed to test for differences in the onset performance of the TrA muscle between the 2 groups.

RESULTS

Results showed that the older group was significantly slower than the younger group in engaging their TrA in response to the rapid arm abduction (P = .036). A separate analysis of the older group data showed that no significant differences existed between the male and female participants that could potentially have acted as a confounding factor for the main finding (P = .126).

CONCLUSIONS

This study shows that older adults were slower than younger adults in activating their TrA muscle in response to rapid arm abduction. This delay has the potential to lead to increased occasions when the low back is unprotected, increasing the likelihood of injury or low back pain.

The effects of core muscle release technique on lumbar spine deformation and low back pain

[Purpose] The purpose of this study was to examine the effects of the core muscle release technique on correction of lumbar deformation and alleviation of low back pain. [Subjects] Ninety patients diagnosed with lumbar deformation and low back pain participated in this study. [Methods] The participants were divided into three groups according to method of treatment. The first group was treated with the core muscle release technique (CRT), the second group was treated with general exercise, and the third group was treated with electrotherapy. The core muscle release technique group received 50-minute of the core muscle release technique 5 times a week for 2 weeks, and the participants in this group were instructed not to receive any other treatments. After the 2 weeks of treatment, the patients were reexamined. The general exercise group performed Williams flexion exercises and McKenzie extension exercises 5 times a week for 2 weeks. The electrotherapy group was treated by application of electrotherapy with an interferential current therapy machine (TM-301. TOPMED. Seongnam, Republic of Korea) to the abdominal muscles and back muscles of the lumbar region. [Results] The data suggest that the core muscle release technique, general exercise, and electrotherapy all helped to decrease the alignment angle and VAS score. Of these treatment methods, however, the core muscle release technique was the most effective for treatment of lumbar spine deformation and low back pain. [Conclusion] The core muscle release technique was most effective for correction of lumbar spine deformation and pain alleviation.

The Effects of Volitional Preemptive Abdominal Contraction on Postural Control Responses in Healthy Subjects

OBJECTIVE

To investigate the effect of volitional preemptive abdominal contraction by using an abdominal bracing maneuver (ABM) on postural control responses.

DESIGN

A within-subjects, repeated-measure, experimental design.

SETTING

Laboratory.

PARTICIPANTS

Sixty-five healthy subjects between 18 and 50 years of age.

METHODS

Subjects performed ABM alternating with No-ABM during 2 rounds of 2 Neurocom computed dynamic posturography tests: the Motor Control Test (MCT) and conditions 1 (eyes open), 2 (eyes closed), and 5 (eyes closed, sway-referenced support) of the Sensory Organization Test (SOT).

MAIN OUTCOME MEASUREMENTS

(1) MCT Response Latency (milliseconds) and Response Scaling (magnitude of active postural correction) and (2) SOT Equilibrium Scores and 2-Dimensional Sway (°/second), and SOT Movement Strategy, which measure postural sway and movement strategies (ankle versus hip strategy), respectively.

RESULTS

The use of ABM (versus No-ABM) produced: (1) a small but statistically significant decrease in SOT Equilibrium Score for condition 2 (-1.0%; P = .004); (2) an increase in SOT 2-Dimensional Sway (°/second) during conditions 1 (16.9%; P = .0001) and 2 (15.0%; P = .0001); (3) a small decrease in SOT Movement Strategy scores during condition 1 (-0.5%; P = .001) and condition 2 (-1.0%; P = .017); and (4) a reduction of MCT Response Latency by 3 milliseconds (-2.1%; P = .005) and reduction of Response Scaling by 0.33°/second (-9.2%; P = .001).

CONCLUSION

Individuals can incorporate the ABM without substantively altering postural control. Although selected SOT and MCT scores exhibited small decreases in postural response integrity, those outcomes did not reflect functionally meaningful changes. These findings can enhance clinicians' confidence in prescribing the ABM as a means to protectively stabilize the spine and potentially prevent injury in healthy subjects without concern for reducing postural control, especially during more complex postural perturbations that introduce sensory conflict.

Relationship between the phases of the menstrual cycle and the transversus abdominis muscle

[Purpose] This study investigated changes in the thickness of the transversus abdominis muscle at various stages of the menstrual cycle. [Subjects] The subjects were 15 young healthy females with regular menstrual cycles. [Methods] A regular menstrual cycle was defined as a 28-day cycle comprising 3 phases: the menstrual phase, the follicular phase, and the luteal phase. For the purpose of the study, measurements were taken at day 3 (menstrual phase), day 12 (follicular phase), and day 21 (luteal phase) of the cycle. An ultrasonic imaging diagnostic device (MyLab 25) and a linear expression probe were used for measurement of the transversus abdominis muscle. [Results] There were no significant differences in the variation rate of the thickness of the muscle at any phase of the menstrual cycle. [Conclusion] The results suggested that the sex hormones associated with the menstrual cycle do not affect the contractility or changes in the thickness of the transversus abdominis muscle. For the reasons stated above, there is little need to consider the menstrual cycle when measuring muscle thickness in physical therapy scenarios because the transversus abdominis muscle does not depend on the menstrual cycle.

Reliability of ultrasound imaging of the transversus abdominis muscle in asymptomatic subjects

[Purpose] The purpose of this study was to assess intra-rater and inter-rater procedural reliability of ultrasound imaging measurements of transversus abdominis thickness. [Subjects] Thirty therapists who attended the B Hospital in Hwaseong participated in the study. [Methods] Two examiners assessed transverse abdominis thickness at rest and during contraction. Intra-class correlation coefficient with 95% confidence interval and, standard error of measurement were calculated. [Results] The intra-rater procedural reliability of ultrasound imaging measurements of transverse abdominis thickness, assessed using the intra-class correlation coefficient, was 0.65-0.86 (within-day, 0.65-0.86; between-day, 0.77-0.85). The inter-rater procedural reliability of ultrasound imaging measurements of transverse abdominis thickness, assessed using the intra-class correlation coefficient, was 0.72-0.86 (within-day, 0.72-0.86; between-day, 0.82-0.83). [Conclusion] Ultrasound imaging can be used as a reliable method for measurements of transverse abdominis thickness.

The effect of complex rehabilitation training for 12 weeks on trunk muscle function and spine deformation of patients with SCI

[Purpose] It is important for patients with incomplete spinal cord injury (SCI) to strengthen their muscle strength and return to the work force one of the ultimate objectives of rehabilitation. This study reports how a single patient with SCI became stabilized in terms of abdominal muscles and back extension muscles, as well as returning the back to the neutral position from spinal deformation, as result of complex exercises performed for 12 weeks. [Subjects] The degree of damage of the subject was rated as C grade. The subject of this study had unstable posture due to paralysis in the lower extremities of the left side after removal of a malignant tumor by surgical operation, and tilting and torsion in the pelvis increased followed by increase of kyphosis in the thoracolumbar spine. The subject was more than two years since diagnosis of incomplete SCI after surgery. [Methods] Using isokinetic lumbar muscle strength measurement equipment, peak torque/weight, total work and average power in flexion and extension of the lumbar region were measured. A trunk measurement system (Formetric 4D, DIERS, Germany), which is a 3D image processing apparatus with high resolution for vertebrae, was used in order to measure 3D vertebrae and pelvis deformation as well as static balance abilities. As an exercise method, a foam roller was used to conduct fascia relaxation massage for warming-up, and postural kyphosis was changed into postural lordosis by lat pull-down using equipment, performed in 5 sets of 15 times preset at 60% intensity of 1RM 4 set of 10 crunch exercises per set using Togu's were done while sitting at the end of Balance pad, and 4 sets of 15 bridge exercises. [Results] All angular speed tests showed a gradual increase in muscle strength. Flexion and extension showed 10% and 3% improvements, respectively. The spine deformation test showed that isokinetic exercise and lat pull-down exercise for 12 weeks resulted in improved spinal shape. [Conclusion] In this study, core stability exercise for deep muscle training and lat pull-down exercise had positive effects on lower extremity muscle strength and the spinal shape of a patient with SCI.

Effects of selective exercise for the deep abdominal muscles and lumbar stabilization exercise on the thickness of the transversus abdominis and postural maintenance

[Purpose] The purpose of this study was to examine the effects of selective exercise for the deep abdominal muscles (SEDA) and lumbar stabilization exercise (LSE) on the thickness of the transversus abdominis and postural maintenance on an unstable base of support. [Subjects and Methods] The subjects of this study were 20 male and 10 female adults in their 20s without lumbar pain. They were equally and randomly assigned to a SEDA group and a LSE group. The thickness of the transversus abdominis was measured using ultrasound imaging during rest and drawing-in. The thickness of the transversus abdominis was measured when subjects raised their right and left legs while lying on a Swiss ball. [Results] Initially, there were no differences between the two groups. After the intervention, significant differences were observed in all parameters. A significant interaction between group and period was not found for any parameters. [Conclusion] In conclusion, both SEDA and LSE thickened the transversus abdominis, which is a deep abdominal muscle, thereby adjusting posture, and stabilizing the trunk. These exercises increased the thickness of the deep abdominal muscles. They are important exercises for improving the stability of athletes or patients who need postural adjustment.

The effect of pelvic compression on deep abdominal muscle thickness during the active straight leg raise test

Background/Aims:

The estimated prevalence of sacroiliac joint (SIJ) pain is 13–30% in patients with non-specific low back pain. One common presentation is pain at or near the SIJ, and common physical therapy interventions include lumbopelvic stabilisation programmes and pelvic compression belts. The aim of this study was to: i) assess how compression of the SIJ affects the thickness of the deep abdominal muscles during the active straight leg raise (ASLR); ii) determine between-day intra-tester reliability of ultrasound imaging to assess percentage change in thickness of the deep abdominal muscles.

Methods:

Participants (n=15) with unilateral symptoms near the SIJ and age-matched and sex-matched controls (n=15) were recruited for this study. Ultrasound imaging was used to obtain the thickness of the transverse abdominis (TrA) and internal oblique (IO) muscles. Measurements were taken at rest and during the ASLR, with and without pelvic compression.

Results:

Two separate two-way (group × pelvic compression) analysis of variance (ANOVA) designs with repeated measures were used to analyse the thickness of the TrA and IO muscles; interactions were not significant for percentage change in the TrA (p=0.57) or IO (p=0.10) muscles. Intra-tester reliability was higher when testing with pelvic compression and in the control group (ICC: 0.85–0.89 vs 0.70–0.76).

Conclusions:

Pelvic compression did not immediately affect the muscular response of the TrA or IO muscles during the ASLR. Pelvic compression belts may be used to address the passive systems of the pelvis by increasing stability; however, specific localised exercises may be needed to improve the percentage change in thickness of the deep abdominal muscles during the ASLR.

The role of ultrasound in diagnosis of the causes of low back pain: a review of the literature

Context:

Low back pain (LBP) is among the most prevalent musculoskeletal conditions in the developed countries. It is a common problem causing disability and imposing a huge economic burden to individuals and state organizations. Imaging plays an important role in diagnosis of the etiology of LBP.

Evidence Acquisition:

The electronic databases included: PubMed (1950 to present), Ovid SP Medline (1950 to present) and ISI (1982 to present) and Google Scholar. In every search engine another search was performed using various permutations of the following keywords: ultrasonography, ultrasound imaging, low back pain, back muscles, paraspinal muscles, multifidus, transverse abdominis, muscle size, spinal canal, sacroiliac joint and spondylolisthesis.

Results:

Magnetic resonance imaging (MRI) is widely used in evaluation of patients with LBP; however, high costs, limited availability and contraindications for its use have restricted MRI utilization. In a quest for a less expensive and readily available tool to investigate LBP, clinicians and researchers found ultrasonography (US) as an alternative. In this review we discuss the US application in diagnosis of some common causes of non-specific chronic LBP. Discussed topics include evaluation of spinal canal diameter, paraspinal and transabdominal muscles, sacroiliac joint laxity, pregnancy related LBP, sacroiliitis, and spondylolisthesis using US in patients with LBP.

Conclusions:

While the first researches on employing ultrasound in diagnosis of patients with LBP had been focused on spinal canal diameter, recent studies have been mostly performed to evaluate the role of transabdominal and paraspinal muscles on core stability and thereby LBP occurrence. On the other side, Doppler ultrasonography has recently played an important role in objective measurement of joint laxity as a common etiology for LBP. Doppler imaging also in pregnant patients with LBP has been recommended as a safe and sensitive method. As conclusion, according to recent and most prestigious studies, focusing more on transabdominal muscle thickness can be considered as future approach in investigations.

Unipedal postural stability in nonathletes with core instability after intensive abdominal drawing-in maneuver

CONTEXT

The exact neuromechanical nature and relative contribution of the abdominal drawing-in maneuver (ADIM) to postural instability warrants further investigation in uninjured and injured populations.

OBJECTIVE

To determine the effects of the ADIM on static core and unipedal postural stability in nonathletes with core instability.

DESIGN

Controlled laboratory study.

SETTING

University research laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 19 nonathletes (4 women: age = 22.3 ± 1.3 years, height = 164.0 ± 1.7 cm, mass = 56.0 ± 4.6 kg; 15 men: age = 24.6 ± 2.8 years, height = 172.6 ± 4.7 cm, mass = 66.8 ± 7.6 kg) with core instability.

INTERVENTION(S)

Participants received ADIM training with visual feedback 20 minutes each day for 7 days each week over a 2-week period.

MAIN OUTCOME MEASURES(S)

Core instability was determined using a prone formal test and measured by a pressure biofeedback unit. Unipedal postural stability was determined by measuring the center-of-pressure sway and associated changes in the abdominal muscle-thickness ratios. Electromyographic activity was measured concurrently in the external oblique, erector spinae, gluteus medius, vastus medialis oblique, tibialis anterior, and medial gastrocnemius muscles.

RESULTS

All participants initially were unable to complete the formal test. However, after the 2-week ADIM training period, all participants were able to reduce the pressure biofeedback unit by a range of 4 to 10 mm Hg from an initial 70 mm Hg and maintain it at 60 to 66 mm Hg with minimal activation of the external oblique (t(18) = 3.691, P = .002) and erector spinae (t(18) = 2.823, P = .01) muscles. Monitoring of the pressure biofeedback unit and other muscle activations confirmed that the correct muscle contraction defining the ADIM was accomplished. This core stabilization was well maintained in the unipedal-stance position, as evidenced by a decrease in the center-of-pressure sway measures (t(18) range, 3.953-5.775, P < .001), an increased muscle-thickness ratio for the transverse abdominis (t(18) = -2.327, P = .03), and a reduction in external oblique muscle activity (t(18) = 3.172, P = .005).

CONCLUSIONS

We provide the first evidence to highlight the positive effects of ADIM training on core and postural stability in nonathletes with core instability.

Interrater and intrarater reliability of transverse abdominal and lumbar multifidus muscle thickness in subjects with and without low back pain

STUDY DESIGN

Two-group, repeated-measures reliability study.

OBJECTIVES

To determine interrater and intrarater reliability of ultrasound measurements of transverse abdominal (TrA) and lumbar multifidus (LM) muscle thickness, during rest and contraction, in subjects with low back pain (LBP) and healthy subjects over 3 consecutive days, performed by an experienced and a novice rater.

BACKGROUND

Previous reliability studies of TrA or LM thickness did not simultaneously account for muscle state, rater experience, and multiday assessment in large subject samples.

METHODS

The 2 raters measured TrA and LM thickness on 3 consecutive days in 42 healthy subjects and 56 subjects with LBP, during rest and contraction, and calculated the percent thickness change from rest to contraction. Intraclass correlation coefficients (ICC(2,k)) and 95% minimal detectable change in thickness were derived for a single measure (day 1) and an average measure (days 1-3).

RESULTS

The interrater ICC(2,1) values for single-measure thickness (LBP group, 0.71-0.87; healthy group, 0.94-1.00) were similar to those for average-measure thickness (LBP group, 0.73-0.84; healthy group, 0.93-1.00). Both interrater ICC(2,1) and ICC(2,3) were lower for the relative thickness change (0.61-0.96). Intrarater ICC(2,1) values across 3 consecutive days were high for both raters across the 2 groups (LBP group, 0.95-1.00; healthy group, 0.93-1.00), albeit lower for the relative thickness change (0.79-0.99). The 95% minimal detectable changes were < 0.3 mm for the TrA and < 2 mm for the LM (but, in most cases, less than 10% of average thickness).

CONCLUSION

Both experienced and trained novice raters provided reliable measurements of TrA and LM thickness in participants with LBP and healthy participants, during rest and contraction. One-time measurements were similar to averaged measurements. Small absolute errors were observed. Public trial registry: Australian New Zealand Clinical Trials Registry ACTRN12613001077752.

Morphological and functional relationships with ultrasound measured muscle thickness of the upper extremity and trunk

Unless a subject's muscle is relatively small, a single image from a standard ultrasound can only measure muscle thickness (MT). Thus, it is important to know whether MT is related to morphological and functional characteristics of individual muscles of the extremity and trunk. In this review, we summarize previously published articles in the upper extremity and trunk demonstrating the relationships between ultrasound-measured MT and muscle morphology (cross-sectional area, CSA and muscle volume, MV) and muscular or respiratory function. The linear relationship between MT and muscle CSA or MV has been observed in biceps brachii, triceps brachii, pectoralis major, psoas major, and supraspinatus muscles. Previous studies suggest that MT in the upper arm and trunk may reflect muscle CSA and MV for the individual muscles. Unfortunately, few studies exist regarding the functional relationship with ultrasound MT in the upper extremity and trunk. Future research is needed to investigate these findings further.

Reversal time of postprandial changes of the thickness of abdominal muscles employing ultrasound measurements

OBJECTIVES

Low thickness of Transversus Abdominis, Internal Oblique and External Oblique muscles may play a role in development of low back pain. Ultrasonography is increasingly utilized to measure the thickness of these muscles. Prandial state has recently been proposed as a confounding factor in such measurements. We aimed to compare the reversal time of the postprandial thickness of these muscles with preprandial values. The measurement errors of ultrasonographic values were also assessed in both immediate preprandial and postprandial states.

DESIGN

Interventional cross-sectional study.

METHODS

The ultrasonographic thickness of lateral abdominal muscles was measured at rest and during abdominal drawing-in maneuver in 20 healthy participants before and after consumption of a specific meal. Postprandial ultrasound measurements continued every 15 min until their thickness reached 95% of their preprandial values.

RESULTS

There was a statistically significant reduction in postprandial thickness of these muscles (all p-values <0.001 on both sides). The reversal times were 1.5, 1.3 and 1.2 h for Transversus Abdominis, Internal Oblique, and External Oblique muscles, respectively. Standard Error of Measurement and Smallest Detectable Change were in the range of 0.007-0.013 mm and 0.020-0.035 mm, respectively.

CONCLUSIONS

To limit the effects of prandial state on the sonographic thickness of lateral abdominal muscles, we recommend measuring these values at least 1.5-2 h after food consumption. For the future studies, controlling the participants according to their prandial state is recommended.

Lateral abdominal muscle size at rest and during abdominal drawing-in manoeuvre in healthy adolescents

Lateral abdominal wall muscles in children and adolescents have not been characterised to date. In the present report, we examined the reliability of the ultrasound measurement and thickness of the oblique external muscle (OE), oblique internal muscle (OI) and transverse abdominal muscle (TrA) at rest and during abdominal drawing-in manoeuvre (ADIM) on both sides of the body in healthy adolescents. We also determined possible differences between boys and girls and defined any factors-such as body mass, height and BMI-that may affect the thickness of the abdominal muscles. B-mode ultrasound was used to assess OE, OI and TrA on both sides of the body in the supine position. Ultrasound measurements at rest and during ADIM were reliable in this age group (ICC3,3 > 0.92). OI was always the thickest and TrA the thinnest muscle on both sides of the body. In this group, an identical pattern of the contribution of the individual muscles to the structure of the lateral abdominal wall (OI > OE > TrA) was observed. At rest and during ADIM, no statistically significant side-to-side differences were demonstrated in either gender. The body mass constitutes between 30% and <50% of the thickness differences in all muscles under examination at rest and during ADIM. The structure of lateral abdominal wall in adolescents is similar to that of adults. During ADIM, the abdominal muscles in adolescents react similarly to those in adults. This study provided extensive information regarding the structure of the lateral abdominal wall in healthy adolescents.

The Effect of the Abdominal Drawing-in Manoeuvre during Forward Steps

[Purpose] A decrease in hip extension has been reported to be a factor in short step width and slow walking speed. Hip motion is related to pelvic and spinal motion, and transversus abdominis (TrA) activation is important for stabilising the pelvis and spine. The abdominal drawing-in manoeuvre (ADIM) can be performed to activate the TrA. The purpose of this study was to examine the influence of the ADIM on forward steps as a gait exercise. [Subjects] The subjects were 20 healthy men (mean age, 20.8 ± 2.4 years). [Methods] Thicknesses of the lateral abdominal muscles during forward step posture with and without ADIM were measured using ultrasound, and kinematics of the hip and pelvis were examined using a three-dimensional motion capture system. [Results] Thicknesses of the TrA and internal oblique increased during forward steps with ADIM. In addition, hip extension increased and pelvic rotation and oblique angles decreased during forward step with ADIM. [Conclusion] We believe that ADIM activates the so-called corset muscles, which consequently stabilise the pelvis and spine and increase hip extension. Our results suggest that an ADIM could increase hip extension during gait exercise.

Ultrasonographic measurement of transverse abdominis in stroke patients

Objective

To compare transverse abdominis (TrA) contractility in stroke patients with hemiparesis and healthy adults using musculoskeletal ultrasonography.

Methods

Forty-seven stroke patients with hemiparesis and 25 age-matched healthy control subjects participated in this study. Stroke patients were divided into three groups on the basis of their degree of ambulation. Group A consisted of 9 patients with wheelchair ambulation, group B of 23 patients with assisted ambulation, and group C of 15 patients with independent ambulation. Inter-rater reliability regarding ultrasonographic measurement of abdominal muscle thickness in the control group was assessed by two examiners. The TrA contraction ratio (TrA contracted thickness/TrA resting thickness) was measured during abdominal drawing-in maneuver and was compared between the patients and the control group and between the ambulation groups.

Results

The inter-rater reliability ranged from 0.900 to 0.947. The TrA contraction ratio was higher in the non-paretic side than in the paretic side (1.40±0.62 vs. 1.14±0.35, p<0.01). The TrA contraction ratio of the patient group was lower in the non-paretic side as well as in the paretic side than that of the control group (right 1.85±0.29, left 1.92±0.42; p<0.001). No difference was found between the ambulation regarding the TrA contraction ratio.

Conclusion

The TrA contractility in hemiparetic stroke patients is significantly decreased in the non-paretic side as well as in the paretic side compared with that of healthy adults. Ultrasonographic measurement can be clinically used in the evaluation of deep abdominal muscles in stroke patients.

Individuals with chronic low back pain do not modulate the level of transversus abdominis muscle contraction across different postures

The aim of this study was to evaluate the thickness of the transversus abdominis (TrA) muscle in three basic postures in subjects with and without chronic low back pain. Subjects were classified into a chronic low back pain group (n = 27) and a healthy control group (n = 23). The thickness of the TrA muscle was measured at rest and during the abdominal drawing-in manoeuvre (ADIM) in supine, sitting and standing postures using B-mode ultrasound imaging. Contraction ratio (TrA thickness during the ADIM/TrA thickness at rest) was calculated for each posture. At rest, the TrA thickness in the sitting and standing postures was significantly greater than in the supine posture (p < 0.017) in the control group, but similar in all three postures in the low back pain group. TrA thickness was similar in the low back pain and control group in all three postures. During the ADIM, TrA thickness was significantly greater in the control group than in the chronic low back pain group in all three postures. The contraction ratio was also significantly higher in the control group than in the chronic low back pain group in all three postures. These results indicate that the automatic postural contraction of the TrA observed in the control subjects in the sitting and standing postures was not demonstrated in subjects with chronic low back pain. The present study revealed the one aspect of different response of the TrA muscle to changing posture between two groups.

Reliability of B-mode sonography of the abdominal muscles in healthy adolescents in different body positions

OBJECTIVES

The primary aim of this study was to determine the reliability of abdominal sonographic measurements in adolescents. The secondary aim was to determine whether age, sex, or body position had an impact on the reliability of abdominal muscle sonographic measurements in adolescents.

METHODS

Sixty-nine asymptomatic participants aged 10 to 15 years without any postural faults participated in the study. The participants were divided into 3 age groups: 10 to 11, 12 to 13, and 14 to 15 years, according to their sex. All participants underwent 3 measurements of the thickness of the transversus abdominis, internal oblique, and external oblique muscles on both sides of the body in the supine, sitting, and standing positions. The participants' measurements were taken at the end of normal exhalation, and the values were recorded in millimeters.

RESULTS

Regardless of the participant's age, sex, and body position, the results for the 3 measurements (intraclass correlation coefficient [ICC(3,3)]) for the transversus abdominis and internal oblique ranged from 0.81 to 0.99. With reference to the external oblique, intraexaminer reliability (ICC(3,3)) in the supine position ranged from 0.81 to 0.98, whereas in the sitting and standing positions, it fluctuated from 0.63 to 0.96.

CONCLUSIONS

Sonography for assessment of the internal oblique and transversus abdominis muscles in different body positions in healthy adolescents aged 10 to 15 years was found to have reliability. To obtain high measurement reliability for the transversus abdominis and internal oblique at rest, at least 2 measurements should be performed, regardless of age, sex, or resting body position. Performing 3 measurements of the external oblique guarantees satisfactory reliability only in the supine position.

The preferential contraction ratios of transversus abdominis on the variations of knee angles during abdominal drawing-in maneuver in wall support standing

The objective of this study was to determine appropriate knee angles for the abdominal drawing-in maneuver (ADIM) through evaluation of changes in contraction ratios of the abdominal muscles and activity of quadriceps muscle in relation to changes in knee angles occurring while the ADIM is performed in the wall support standing (WSS). 20 subjects performed the ADIM at different knee angles (0°, 20°, 40°, 60°) in random order, standing at a point 6 inches away from the wall with the spine maintained in the neutral position. The WSS with knee flexion at 20° showed significantly higher preferential contraction ratio (PCR) of transversus abdominis (TrA) compared to other positions (0°, 40°, 60°). Therefore, performing the ADIM in the WSS with knee flexion at 20° appears to be the most appropriate position for TrA PCR.

Separate assessment of gluteus medius and minimus: B-mode or M-mode ultrasound?

The hip abductors gluteus medius (Gmed) and minimus (Gmin) differ slightly in function and how they are affected by hip joint pathology. A separate assessment of Gmed and Gmin is feasible by ultrasound (US) imaging. B-mode and M-mode US can be used to measure muscle thickness. Two B- and two M-mode scans of Gmed and Gmin thickness were taken in relaxation on 16 asymptomatic volunteers, repeated within 4 days on 11 subjects. Three types of intra-rater reliability of muscle thickness measurements were examined: (1) within-session reliability comparing two scans from the same session, (2) between-days reliability comparing thickness from two scanning occasion within 4 days and (3) reliability of taking thickness measurements by re-measuring the same US scans after 1 week. Thickness measurements on B- and M-mode images provided ICC3,1 >0.96 for within-session reliability. ICC3,k >0.89 for between-days reliability and ICC3,1 >0.85 for re-reading the same scans were estimated. Minimal detectable changes >1.0 mm within-session, >2.4 mm between-days and >1.7 mm for re-reading scans indicated that small thickness changes are not detectable. The investigation suggests a slight advantage for fascia recognition in B-mode and the advantage of visual control of muscle relaxation in M-mode.

Effect of recurrent low back pain history on volitional pre-emptive abdominal activation during a loaded functional reach activity

STUDY DESIGN

A 2 (group) × 2 (abdominal contraction) × 2 (reach activity) crossover mixed design with repeated measures for contraction and activity examined the effects of a loaded (4.6 kg) forward-reach activity and abdominal drawing-in maneuver (ADIM) on transversus abdominis (TrA) contraction in subjects with nonspecific low back pain (NSLBP) history versus controls.

OBJECTIVE

We measured TrA contraction during a loaded forward-reach activity while using the ADIM and examined if a NSLBP history affects TrA activity.

SUMMARY OF BACKGROUND DATA

The ADIM supports trunk stability during function. Clinicians incorporate ADIM during patients' functional tasks. Pain-free individuals can sustain ADIM during function, such as forward-reach. However, this has not been tested in those with a NSLBP history.

METHODS

Eighteen normal subjects and 18 subjects with a history of NSLBP participated. A blinded investigator recorded M-mode ultrasound imaging measurements of TrA thickness (mm) during 4 conditions as follows: (1) quiet standing without ADIM; (2) quiet standing with ADIM; (3) loaded forward-reach without ADIM; and (4) loaded forward-reach with ADIM.

RESULTS

A mixed analysis of variance demonstrated a significant main effect for group (F [1, 34] = 5.404, P = 0.026; ), where TrA thickness was greater for NSLBP history (7.41 + 2.34 mm) versus controls (5.9 + 2.46 mm). A significant main effect was observed for abdominal contraction (F [1, 34] = 49.57, P < 0.0001; ), where TrA thickness was greater during ADIM (7.47 + 2.7 mm) versus without ADIM (5.84, 1.92 m). A significant main effect was observed for forward-reach activity (F [1, 34] = 12.79, P = 0.001; ), where TrA thickness was greater during a loaded forward-reach (7.04 + 2.6 mm) versus quiet standing (6.2 + 2.4 mm). There were no significant interactions.

CONCLUSION

Individuals can use a volitional pre-emptive ADIM for trunk protection during loaded forward-reach, potentially reducing injury risk. A NSLBP history increases TrA activation during ADIM, suggesting an enhanced protective role.

LEVEL OF EVIDENCE

2.

The Effects of Stabilization and Mckenzie Exercises on Transverse Abdominis and Multifidus Muscle Thickness, Pain, and Disability: A Randomized Controlled Trial in NonSpecific Chronic Low Back Pain

[Purpose] This study compared the effectiveness of stabilization and McKenzie exercises on pain, disability, and thickness of the transverse abdominis and multifidus muscles in patients with nonspecific chronic low back pain. [Subjects] Thirty patients were randomly assigned into two groups: the McKenzie and stabilization exercise groups. [Methods] Before and after intervention, pain, disability, and thickness of the transverse abdominis and multifidus muscles were evaluated by visual analogue scale, functional rating index, and sonography, respectively. The training program was 18 scheduled sessions of individual training for both groups. [Results] After interventions, the pain score decreased in both groups. The disability score decreased only in the stabilization group. The thickness of the left multifidus was significantly increased during resting and contracting states in the stabilization group. The thickness of the right transverse abdominis during the abdominal draw-in maneuver, and thickness of the left transverse abdominis during the active straight leg raising maneuver were significantly increased in the stabilization group. The intensity of pain, disability score, thickness of the right transverse abdominis during the abdominal draw-in manouver, and thickness of the left transverse abdominis during active straight leg raising in the stabilization group were greater than those on the Mackenzie. [Conclusion] Stabilization exercises are more effective than McKenzie exercises in improving the intensity of pain and function score and in increasing the thickness of the transverse abdominis muscle.

A clinical prediction rule to identify patients with low back pain who are likely to experience short-term success following lumbar stabilization exercises: a randomized controlled validation study

STUDY DESIGN

Randomized controlled trial.

OBJECTIVE

To determine the validity of a previously suggested clinical prediction rule (CPR) for identifying patients most likely to experience short-term success following lumbar stabilization exercise (LSE). Background Although LSE is commonly used by physical therapists in the management of low back pain, it does not seem to be more effective than other interventions. A 4-item CPR for identifying patients most likely to benefit from LSE has been previously suggested but has yet to be validated.

METHODS

One hundred five patients with low back pain underwent a baseline examination to determine their status on the CPR (positive or negative). Patients were stratified by CPR status and then randomized to receive an LSE program or an intervention consisting of manual therapy (MT) and range-of-motion/flexibility exercises. Both interventions included 11 treatment sessions delivered over 8 weeks. Low back pain-related disability was measured by the modified version of the Oswestry Disability Index at baseline and upon completion of treatment.

RESULTS

The statistical significance for the 2-way interaction between treatment group and CPR status for the level of disability at the end of the intervention was P = .17. However, among patients receiving LSE, those with a positive CPR status experienced less disability by the end of treatment compared with those with a negative CPR status (P = .02). Also, among patients with a positive CPR status, those receiving LSE experienced less disability by the end of treatment compared with those receiving MT (P = .03). In addition, there were main effects for treatment and CPR status. Patients receiving LSE experienced less disability by the end of treatment compared to patients receiving MT (P = .05), and patients with a positive CPR status experienced less disability by the end of treatment compared to patients with a negative CPR status, regardless of the treatment received (P = .04). When a modified version of the CPR (mCPR) containing only the presence of aberrant movement and a positive prone instability test was used, a significant interaction with treatment was found for final disability (P = .02). Of the patients who received LSE, those with a positive mCPR status experienced less disability by the end of treatment compared to those with a negative mCPR status (P = .02), and among patients with a positive mCPR status, those who received LSE experienced less disability by the end of treatment compared to those who received MT (P = .005).

CONCLUSION

The previously suggested CPR for identifying patients likely to benefit from LSE could not be validated in this study. However, due to its relatively low level of power, this study could not invalidate the CPR, either. A modified version of the CPR that contains only 2 items may possess a better predictive validity to identify those most likely to succeed with an LSE program. Because this modified version was established through post hoc testing, an additional study is recommended to prospectively test its predictive validity.

LEVEL OF EVIDENCE

Prognosis, level 1b-.

Variability in diaphragm motion during normal breathing, assessed with B-mode ultrasound

STUDY DESIGN

Clinical measurement, cross-sectional.

OBJECTIVES

To establish a set of normal values for diaphragm thickening with tidal breathing in healthy subjects.

BACKGROUND

Normal values for diaphragm contractility, as imaged sonographically, have not been described, despite the known role of the diaphragm in contributing to spinal stability. If the normal range of diaphragm contractility can be defined in a reliable manner, ultrasound has the potential to be used clinically and in research as a biofeedback tool to enhance diaphragm activation/contractility.

METHODS

B-mode ultrasound was performed on 150 healthy subjects to visualize and measure hemi-diaphragm thickness on each side at resting inspiration and expiration. Primary outcome measures were hemi-diaphragm thickness and thickening ratio, stratified for age, gender, and body mass index. Interrater and intrarater reliability were also measured.

RESULTS

Normal thickness of the diaphragm at rest ranged from 0.12 to 1.18 cm, with slightly greater thickness in men but no effect of age. Average ± SD change in thickness from resting expiration to resting inspiration was 20.0% ± 15.5% on the right and 23.5% ± 24.4% on the left; however, almost one third of healthy subjects had no to minimal diaphragm thickening with tidal breathing.

CONCLUSION

There is wide variability in the degree of diaphragm contractility during quiet breathing. B-mode ultrasound appears to be a reliable means of determining the contractility of the diaphragm, an important muscle in spinal stability. Further studies are needed to validate this imaging modality as a clinical tool in the neuromuscular re-education of the diaphragm to improve spinal stability in both healthy subjects and in patients with low back pain.

Transversus abdominis activation during a side-bridge exercise progression is similar in people with recurrent low back pain and healthy controls

Low back pain (LBP) affects 70-80% of the population. The transversus abdominis (TrA) has been implicated as part of the cause of LBP. Prevention and rehabilitation of LBP often target the TrA using exercises such as the side bridge accompanied with the abdominal drawing-in maneuver (ADIM). However, it is unknown whether individuals with recurrent LBP, when they are in a period of no pain, are able to activate the TrA and healthy individuals during this exercise. The purpose of our study was to compare the activation ratio of the TrA during a 5-level side-bridge exercise progression. Twenty-three subjects with a history of recurrent, nonspecific LBP, but not experiencing an exacerbation of symptoms and 24 healthy controls volunteered. All the subjects performed the ADIM and side-bridge exercises with clinician feedback (verbal cueing). Each participant performed the side-bridge exercise progression while ultrasound images were taken. The subjects were only progressed if they successfully completed the previous level. The thickness of the TrA was measured in rested and contracted states at each exercise level to find the activation ratio (TrA contracted/TrA rest). Separate analyses of covariance did not reveal a difference in activation ratios between groups (p > 0.40) when the ratio at the lowest level was used as the covariate. The results from this study indicate that both groups were able to contract the TrA with verbal cueing during a side-bridge exercise progression. Because the TrA contracted similarly during exercise in both groups, the association of LBP with the TrA may be because of another mechanism, such as delayed activation in the feed-forward mechanism during activity or a lack of endurance of the TrA.

Reliability of ultrasound measurement of automatic activity of the abdominal muscle in participants with and without chronic low back pain

Background

Ultrasound (US) imaging has been considered as a non-invasive technique to measure thickness and estimate relative abdominal muscle activity. Although some studies have assessed the reliability of US imaging, no study has assessed the reliability of US measurement of automatic activity of abdominal muscles in positions with different levels of stability in participants with chronic low back pain (cLBP). The purpose of this study was to investigate within-day and between-days reliability of US thickness measurements of automatic activity of the abdominal muscles in asymptomatic participants and within-day reliability in those with cLBP.

Methods

A total of 20 participants (10 with cLBP, 10 healthy) participated in the study. The reliability of US thickness measurements at supine lying and sitting positions (sitting on a chair, sitting on a gym ball with both feet on the ground or lifting one foot off the floor) were assessed. We evaluated within-day reliability in all participants and between-days reliability in asymptomatic participants.

Results

We found high ICC scores (0.85-0.95) and also small SEM and MDC scores in both groups. The reliability of the measurements was comparable between participants with and without LBP in each position but the SEMs and MDCs was slightly higher in patient group compared with healthy group. It indicates high intra-tester reliability for the US measurement of the thickness of abdominal muscles in all positions.

Conclusion

US imaging can be used as a reliable method for assessment of automatic activity of abdominal muscles in positions with low levels of stability in participants with and without LBP.

Comparison of contraction rates of abdominal muscles of chronic low back pain patients in different postures

[Purpose] This study examined the contraction rates of abdominal muscles in relation to the posture of chronic lumbar pain patients and normal subjects. [Subjects] The subjects were 17 chronic low back pain (CLBP) patients and 17 normal people between the ages of 20 and 59. [Methods] Experimental postures included a supine position, a sitting position, and a standing position. Measurements were taken at rest and during abdominal contraction. The measurement at rest was taken during expiration with comfortable breathing, and the measurement during contraction was taken at maximum expiration of forced expiration. Muscle contraction rates (on contraction and at relaxation) were calculated. [Results] There were significant differences between CLBP patients and normal subjects in the transversus abdominis (TrA) in the standing position. [Conclusion] Changes in contraction rates of the abdominal muscles of normal subjects and CLBP patients were examined in different postures at maximum expiration. It was found that the contraction rate of TrA in CLBP patients in a standing position, is significantly lower than that of normal subjects.