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

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

OBJECTIVE

To investigate the immediate changes in resting and contracted thickness of the transversus abdominis (TrA) muscle after application of thrust joint manipulation (TJM) vs sham manipulation in participants with low back pain.

METHODS

A pretest-posttest randomized controlled trial design was performed. Consecutive subjects satisfying eligibility criteria completed patient-report outcome baseline measures, pretreatment rehabilitative ultrasound imaging (RUSI) measurements, followed by the randomly assigned intervention then, post-treatment RUSI measurements, and post-treatment & final patient-reported outcome measures. To compare the outcomes of TJM and sham manipulation on the TrA muscle thickness, a 2-by-2 analysis of variance (treatment [TJM and sham manipulation]) by time (pretreatment and post-treatment) was completed for both the TrA muscle thickness at rest and muscle thickness during contraction. Descriptive statistics including independent-sample t tests for continuous variables and χ² tests for categorical variables were used to analyze differences in patient-reported outcome measures between groups.

RESULTS

Sixty-seven eligible participants agreed to participate. No significant interactions were identified for either muscle thickness at rest or contraction.

CONCLUSION

This study did not support the hypothesis that manipulation would result in greater changes in TrA thickness at rest or during contraction in participants with low back pain. Based on prior research that identified subgroups of participants likely to respond to manipulation, future research should include participants more likely to respond favorably to TJM. This study was a priori registered with clinicaltrails.gov (NCT02558855).

Role of Ultrasound in Low Back Pain: A Review

Low back pain is one of most common musculoskeletal disorders around the world. One major problem clinicians face is the lack of objective assessment modalities. Computed tomography and magnetic resonance imaging are commonly utilized but are unable to clearly distinguish patients with low back pain from healthy patients with respect to abnormalities. The reason may be the anisotropic nature of muscles, which is altered in function, and the scans provide only structural assessment. In view of this, ultrasound may be helpful in understanding the disease as it is performed in real-time and comprises different modes that measure thickness, blood flow and stiffness. By the use of ultrasound, patients with low back pain have been found to differ from healthy patients with respect to the thickness and stiffness of the transversus abdominis, thoracolumbar fascia and multifidus. The study results are currently still not conclusive, and further study is necessary to validate. Future work should focus on quantitative assessment of these tissues to provide textural, structural, hemodynamic and mechanical studies of low back pain. This review highlights the current understanding of how medical ultrasound has been used for diagnosis and study of low back pain and discusses potential new applications.

Application of Ultrasonography in the Assessment of Abdominal and Lumbar Trunk Muscle Activity in Participants With and Without Low Back Pain: A Systematic Review

OBJECTIVE

The purpose of this study was to systematically review the literature regarding which condition (task, position, or contraction type), changes in muscle thickness could be interpreted as muscle activity of trunk muscles.

METHODS

Studies that assessed the correlation between changes in muscle thickness measured with ultrasonography (US) and electromyography (EMG) activity were included. Only the data related to abdominal and lumbar trunk muscles in participants with or without low back pain were extracted. The PubMed, ScienceDirect, Ovid MEDLINE, Scopus, Springer, and Cumulative Index to Nursing and Allied Health Literature databases were searched from inception to August 2018. Two independent raters appraised the quality of the included studies using the Critical Appraisal Skills Program checklist.

RESULTS

Fourteen studies were included. The results revealed significant correlations between US and EMG measures for the lumbar multifidus and erector spinae muscle during most contraction levels and postures. For transverse abdominis and internal oblique, US and EMG measures were correlated during low load abdominal drawing or bracing. The correlations were influenced by trunk position for higher intensities of contraction. For the external oblique muscle, correlation was observed only during trunk rotation.

CONCLUSION

Changes in muscle thickness should not be interpreted as muscle activity for all tasks, positions, and contraction types. Only during prime movement tasks performed with isometric contraction could muscle thickness change be considered as muscle activity. Also, upright postures influenced the relationship between changes in muscle thickness and muscle activity for abdominal muscles.

Comparison of Lateral Abdominal Musculature Activation during Expiration with an Expiratory Flow Control Device Versus the Abdominal Drawing-in Maneuver in Healthy Women: A Cross-Sectional Observational Pilot Study

Background and Objectives: The purpose of the present study was to quantify and compare lateral abdominal musculature thickness, including the transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) muscles, via rehabilitative ultrasound imaging (RUSI) during the use of the expiratory flow control device (EFCD) versus the classic abdominal drawing-in maneuver (ADIM). Materials and Methods: A cross-sectional observational pilot study. Twenty-one women were recruited and assessed the thickness of each muscle (TrA, IO, and EO) by ultrasound imaging at rest, during the ADIM, and during expiration with the EFCD. Waist circumference was also measured under the same circumstances. Results: Statistically significant differences were observed between ADIM, EFCD, and at rest condition for the thickness of the TrA (p = 0.001) and IO (p = 0.039). Moreover, statistically significant differences for TrAb at rest compared with the ADIM (p = 0.001, Cohen’s d = 2.183) and at rest and with the EFCD (p = 0.001, Cohen’s d = 2.843). In addition, between ADIM and EFCD were not statistically significant, although a moderate effect size was found (p = 0.055, Cohen’s d = 0.694). For the IO muscle thickness, significant differences were reported between the EFCD and at rest (p = 0.038), Cohen’s d = 0.081). Conclusions: Significant differences in the increase of the thickness of the TrA and IO muscles during the use of the EFCD and the ADIM with respect to rest. In addition, for the TrA, statistically significant differences were found during expiration with the EFCD with respect to the ADIM. Expiration with EFCD can be a useful method for the activation of the TrA.

Comparison of the recruitment of transverse abdominis through drawing-in and bracing in different core stability training positions

There are many proposed core stability exercises in a variety of positions; however, it is not clear that in which position, activation of transverse abdominis muscle is utmost. We aimed to compare the activation of transverse abdominis muscle in different core stability exercise positions through ultrasound imaging. in a 20 subjects' study we compared the effectiveness of drawing-in and bracing maneuvers on transverse abdominis in different core stability exercise positions (supine, hook lying, supine with 90° flexed knee and hip, supine with stretched knees and 90° flexed hips, bridge, bridge with one stretched knee and Bird dog). We used activation ratio and preferential activation ratio as measurements of transverse abdominis activation. Abdominal Bracing in the bridge position showed the highest activation of transverse abdominis (P<0.05). The results showed significantly higher activation of transverse abdominis, measured by preferential activation ratio, in bridge position during abdominal bracing.

Ultrasound Imaging of the Gluteal Muscles During the Y-Balance Test in Individuals With or Without Chronic Ankle Instability

CONTEXT

Impairments in dynamic postural control and gluteal muscle activation have been associated with the development of symptoms related to long-term injury, which are characteristic of chronic ankle instability (CAI). Ultrasound imaging (USI) provides a visual means to explore muscle thickness throughout movement; however, USI functional-activation ratios (FARs) of the gluteal muscles during dynamic balance exercises have not been investigated.

OBJECTIVE

To determine differences in gluteus maximus and gluteus medius FARs using USI, Y-Balance Test (YBT) performance, and lower extremity kinematics in individuals with or without CAI.

DESIGN

Cross-sectional study.

SETTING

University laboratory.

PATIENTS OR OTHER PARTICIPANTS

Twenty adults with CAI (10 men, 10 women; age = 21.70 ± 2.32 years, height = 172.74 ± 11.28 cm, mass = 74.26 ± 15.24 kg) and 20 adults without CAI (10 men, 10 women; age = 21.20 ± 2.79 years, height = 173.18 ± 15.16 cm, mass = 70.89 ± 12.18 kg).

INTERVENTION(S)

Unilateral static ultrasound images of the gluteal muscles during quiet stance and to the point of maximum YBT reach directions were obtained over 3 trials. Hip, knee, and ankle sagittal-plane kinematics were collected with motion-capture software.

MAIN OUTCOME MEASURE(S)

Gluteal thickness was normalized to quiet stance to yield FARs for each muscle in each YBT direction. We averaged normalized reach distances and obtained average peak kinematics. Independent t tests, mean differences, and Cohen d effect sizes were calculated to determine group differences for all outcome measures.

RESULTS

The CAI group had anterior-reach deficits compared with the control group (mean difference = 4.37%, Cohen d = 0.77, P = .02). The CAI group demonstrated greater anterior gluteus maximus FARs than the control group (mean difference = 0.08, Cohen d = 0.57, P = .05).

CONCLUSIONS

The CAI group demonstrated YBT reach deficits and alterations in proximal muscle activation. Increased reliance on the gluteus maximus during dynamic conditions may contribute to distal joint dysfunction in this population.

Effects of a 6-week intrinsic foot muscle exercise program on the functions of intrinsic foot muscle and dynamic balance in patients with chronic ankle instability

We aimed to evaluate the effects of a 6-week intrinsic foot muscle exercise program on the activation of intrinsic foot muscle movement and dynamic balance in adults with chronic ankle stability. A total of 30 adults with chronic ankle instability were recruited. The participants were randomly assigned to a group performing intrinsic foot muscle exercises and a control group doing no exercises. We measured the activation rate and dynamic balance of the abductor hallucis, flexor digitorum brevis, flexor hallucis brevis, and quadratus plantae before and after the intervention. We found that the activation rate and dynamic balance significantly increased in all intrinsic foot muscles in the experimental group. These results suggest that intrinsic foot muscle exercise for patients with chronic ankle stability is an effective treatment for improving the functions and balance ability of the intrinsic foot muscles.

Ultrasonography of Gluteal and Fibularis Muscles During Exercises in Individuals With a History of Lateral Ankle Sprain

CONTEXT

Individuals with a history of lateral ankle sprains (LASs) have ankle and hip neuromuscular changes compared with those who do not have a history of LAS.

OBJECTIVE

To compare gluteus maximus (GMax), gluteus medius (GMed), and fibularis longus and brevis muscle activation using ultrasound imaging during tabletop exercises and lateral resistance-band walking in individuals with or without a history of LAS or chronic ankle instability (CAI).

DESIGN

Cross-sectional study.

PATIENTS OR OTHER PARTICIPANTS

Sixty-seven young adults (27 males, 40 females). Groups were healthy = 16, coper = 17, LAS = 15, CAI = 19. The number of previous sprains was 0 ± 0 in the healthy group, 1.1 ± 0.3 in the coper group, 2.9 ± 2.4 in the LAS group, and 5.3 ± 5.9 in the CAI group.

MAIN OUTCOME MEASURE(S)

Ultrasound imaging measures of fibularis cross-sectional area (CSA) were collected during nonresisted and resisted ankle eversion. Gluteal muscle thicknesses were imaged during nonresisted and resisted side-lying abduction and during lateral resistance-band walking exercises (lower leg and forefoot band placement). Separate 4 × 2 repeated-measures analyses of variance and post hoc Fisher least significant difference tests were used to assess activation across groups and resistance conditions.

RESULTS

All groups demonstrated 3.2% to 4.1% increased fibularis CSA during resisted eversion compared with nonresisted. During side-lying abduction, the LAS and CAI groups displayed increased GMax thickness (6.4% and 7.2%, respectively), and all but the CAI group (-0.4%) increased GMed thickness (5.3%-11.8%) with added resistance in hip abduction. During band walking, the healthy and LAS groups showed increased GMax thickness (4.8% and 8.1%, respectively), and all groups had increased GMed thickness (3.0%-5.8%) in forefoot position compared with the lower leg position. Although the values were not different, copers exhibited the greatest amount of GMed thickness during band-walking activities (copers = 23%-26%, healthy = 17%-23%, LAS = 11%-15%, CAI = 15%-19%).

CONCLUSIONS

All groups had increased fibularis CSA with resisted eversion. In side-lying hip abduction, individuals with CAI had greater GMax thickness than GMed thickness. Ultrasound imaging of fibularis CSA and gluteal muscle thickness may be clinically useful in assessing and treating patients with LAS or CAI.

The effectiveness of transverse abdominis training on balance, postural sway and core muscle recruitment patterns: a pilot study comparison across age groups

[Purpose] This pilot study aims to determine whether improvements in postural sway, particularly among older adults, can be augmented immediately after training participants to activate and isolate the transverse abdominis (TrA) muscle. [Participants and Methods] Fifty six participants (in three age groups) took part in a single session TrA training intervention. Aspects of postural sway, balance and muscle activation patterns were measured before and after training and compared. [Results] There was significant improvement across four of six postural sway variables for the combined sample of all age groups. Older adults improved more than younger and middle-age participants in two important postural sway variables. No marked differences were evident in static reach distance across all age groups. There were no differences between groups with regard to surface electromyography (sEMG) amplitudes despite the emergence of different activation patterns among age groups. [Conclusion] Immediate effects were induced in postural sway measures after the single session training intervention. By improving neuromuscular control of the TrA and maximizing the efficiency of related proximal core muscles center of pressure (COP) sway velocities decreased during single limb standing (SLS).

Examination of the intrarater reliability of ultrasound measurements of the thickness of the lumbar and lateral abdominal muscles in the prone position

[Purpose] This study aimed to examine the intrarater reliability when measuring the thickness of the lumbar and lateral abdominal muscles using ultrasound with the participants in the prone position. [Participants and Methods] The participants were 10 healthy adult males without chronic low back pain. The muscle thicknesses of the lumbar multifidus, erector spinae, obliquus externus abdominis, obliquus internus abdominis, and transversus abdominal muscles were measured using ultrasound with the participants in the prone position. [Results] The intraclass correlation coefficients of the within-day and between-day intrarater reliability measurements were 31.1–34.1 mm (lumbar multifidus), 32.0–33.5 mm (erector spinae), 7.4–8.0 mm (obliquus externus abdominis), 9.4–10.4 mm (obliquus internus abdominis), and 2.9–3.4 mm (transversus abdominal). The standard error of measurement and 95% confidence interval of minimal detectable change of the within- and between-day measurements were 0.1–1.2 mm and 0.3–3.4 mm, respectively, for each muscle. [Conclusion] The reliability of measuring the lumbar and lateral abdominal muscles in the prone position using ultrasound was confirmed. It was suggested that measurements during muscle activity and extremity movement are possible when participants are in the prone position.

Analysis of Motor Control in Patients With Low Back Pain: A Key to Personalized Care?

SYNOPSIS

Motor control exercise has been shown to be effective in the management of low back pain (LBP). However, the effect sizes for motor control exercise are modest, possibly because studies have used a one-size-fits-all approach, while the literature suggests that patients may differ in presence or type of motor control issues. In this commentary, we address the question of whether consideration of such variation in motor control issues might contribute to more personalized motor control exercise for patients with LBP. Such an approach is plausible, because motor control changes may play a role in persistence of pain through effects on tissue loading that may cause nociceptive afference, particularly in the case of peripheral sensitization. Subgrouping systems used in clinical practice, which comprise motor control aspects, allow reliable classification that is, in part, aligned with findings in studies on motor control in patients with LBP. Motor control issues may have heuristic value for treatment allocation, as the different presentations observed suggest different targets for motor control exercise, but this remains to be proven. Finally, clinical assessment of patients with LBP should take into account more aspects than motor control alone, including pain mechanisms, musculoskeletal health, and psychosocial factors, and may need to be embedded in a stratification approach based on prognosis to avoid undue diagnostic procedures. J Orthop Sports Phys Ther 2019;49(6):380-388. Epub 12 Jun 2018. doi:10.2519/jospt.2019.7916.

Deformations of abdominal muscles under experimentally induced low back pain

PURPOSE

Low back pain (LBP) is associated with altered motor control and muscle activity; however, it remains unknown whether these changes predispose humans to injury and pain or are the consequence of ongoing nociceptive processes. In this experimental study, we aimed to use a novel ultrasound imaging technique for the measurement of lateral abdominal wall muscle activity: the tissue deformation index (TDI).

METHODS

Forty-two healthy subjects (22.30 ± 1.49 years of age) were exposed to postural perturbation induced by rapid arm movement. Activity of three muscles, the transversus abdominis (TrA) and the internal and external oblique (EO), was recorded by ultrasound imaging (M-mode) with and without induction of LBP. Pain was induced by electrical stimulation applied bilaterally to the lumbar spine.

RESULTS

No significant differences in the TDI between right and left sides of the body (p > 0.05) were found. Generally, muscles deformed slower with pain compared to non-painful conditions; however, only EO muscle displayed a statistically significant reduction in deformation velocity (p ≤ 0.00001). TDI for EO decreased from 0.065% per ms ( ± 0.038, 95% CI 0.057-0.074) to 0.053% per ms ( ± 0.035, 95% CI 0.046-0.061). Furthermore, characteristic inter-muscular TDI gradients were observed, directed from inner towards outer muscular layers, with TrA showing the lowest TDI and EO the highest.

CONCLUSION

Experimentally induced LBP suppresses deformation of the superficial abdominal muscles and increases the variability of local/deep muscles. Further research is required to confirm these observations. These slides can be retrieved under Electronic Supplementary Material.

Effects of a 4-Week Intrinsic Foot Muscle Exercise Program on Motor Function: A Preliminary Randomized Control Trial

Context: Intrinsic foot muscle (IFM) exercises are utilized clinically in the treatment of foot and ankle conditions. However, the effectiveness of training on IFM motor function is unknown. Objective: To study the effects of a 4-week IFM exercise program on motor function, perceived difficulty, and IFM motor activation measured using ultrasound imaging (USI) during 3 IFM exercises. Design: Single-blinded randomized control trial. Setting: Laboratory. Participants: A total of 24 healthy, recreationally active young adults without history of ankle-foot injury who have never performed IFM exercises participated (12 males and 12 females; mean age = 21.5 [4.8] y; body mass index = 23.5 [2.9] kg/m²) Intervention: Following randomization, participants allocated to the intervention group received a 4-week progressive home IFM exercise program performed daily. Participants in the control group did not receive any intervention. Main Outcome Measures: Clinician-assessed motor performance (4-point scale: 0 = does not initiate movement and 3 = performs exercise in standard pattern), participant-perceived difficulty (5-point Likert scale: 1 = very easy and 5 = very difficult), and USI motor activation measures (contracted measurementresting measurement) of the abductor hallucis, flexor digitorum brevis, quadratus plantae, and flexor hallucis brevis were assessed during toe-spread-out, hallux-extension, and lesser-toe-extension exercises. Results: The intervention group demonstrated significant improvement in motor performance in the toe-spread-out exercise (pre = 1.9 [0.5], post = 2.6 [0.5], P = .008) and less perceived difficulty in the toe-spread-out (pre = 3.1 [1.3], post = 2.3 [1.2], P = .01), hallux-extension (pre = 3.2 [1.5], post = 2.0 [1.2], P = .005), and lesser-toe-extension (pre = 1.9 [0.7], post = 1.2 [0.4], P = .03) exercises. Both groups demonstrated increased USI motor activation in the abductor hallucis during the toe-spread-out exercise (intervention: pre = 1.07 [0.06], post = 1.11 [0.08] and control: pre = 1.08 [0.06], post = 1.11 [0.06]; P = .05). No other significant main effects or group by time interactions were observed. Conclusion: A 4-week IFM exercise intervention resulted in improved motor performance and decreased perceived difficulty when performing the exercises, but not changes in USI measures of IFM activation compared with a control group.

Reliability and Validity of the Feedback Sensor for Activating the Transversus Abdominis Muscle

Background:

Core muscle activation is an effective intervention for the management of Low Back Pain (LBP). This study developed new feedback for detecting activation of the transversus abdominis muscle in the lumbar spine. The purpose of this study was to examine the validity and reliability of the feedback device for transversus abdominis muscle contraction.

Methods:

The participants in this study were 20 healthy males and females (aged 24.1 ± 6.8 years). The feedback sensor was attached to the lumbar support at the front of the trunk. The participants performed an abdominal drawing-in maneuver in order to activate the transversus abdominis muscle, and values from the feedback sensor were collected at the same time. Ultrasound imaging of the transversus abdominis muscle was also collected simultaneously. The feedback sensor collected values at different clinical levels of the pressure biofeedback unit at 64, 66, 68, and 70 mmHg. The protocol was repeated with a 24-hr interval. Intra-class correlation coefficient, coefficient of variation and standard error of measurements were used to examine reliability. The validity of the values obtained from the relationship between the feedback sensor and transversus abdominis muscle thickness was analyzed using Pearson’s correlation coefficients.

Results:

Test–retest reliability of the feedback sensor was excellent (ICC = 0.946, CV = 2.6%, SEMs = 0.54%). Values of the feedback sensor reported a significantly moderate correlation with the gold standard ultrasound measurement (r = - 0.514, p < 0.001).

Conclusion:

The feedback device demonstrated potential reliability and validity for clinical use by indicating activation of the transversus abdominis muscle.

Evaluation of transverse abdominal muscle thickness and the quality of life in patients undergoing rehabilitation due to disc-root conflict in the lumbo-sacral spine treated surgically using the spinal disc resection method

Purpose: The aim of the study was to determine the relationship between the changes in abdominal transverse muscle thickness (TrA) after therapy that included elements of reeducation of central stabilisation, and pain reduction as well as quality of patients’ life after intervertebral disc resection of lumbar spine. Material and methods: The study group consisted of 30 patients (17 women and 13 men) aged 28-87 (58 ± 15) participating in a rehabilitation stay. All subjects underwent intervertebral disc resection (LS level) within the years 2012-2016. All subjects included in the study underwent ultrasound evaluation of the thickness of the TrA muscle, evaluation of activation ratio, percentage change in muscle thickness, evaluation of the quality of life with SF-36, assessment of pain components on the VAS scale and level of disability using the Barthel index. All the subjects were referred to a 3-week therapy programme combined with motor control re-education including deep muscle training. The tests were performed before and after the physiotherapy on the basis of the original exercise programme. Results and conclusions: The percentage of TrA muscle thickness change in the first exam was 15.84 ±0.1%, and 16.09 ±0.13% after treatment. There were no statistically significant differences between the measurements. In the assessment of quality of life, patients in the first exam reached the score of 113.23 ±28.07 points, whereas in the second one - 85.1 ±27.05 points. The difference between the results was statistically significant (p<0.001). Pain components on the VAS scale were assessed at 4.3 ±0.83 points on average in the former exam, and 2.83 ±1.04 points in the latter one. The difference in measurements was statistically significant (p<0.001). The assessment of the level of disability using the Barthel scale with an average score of 93.66 ±8.4 points, conducted in the first exam, indicated that the studied persons were characterised by full efficiency. The original therapy, carried out among subjects operated on due to disc-root conflict of the LS spine, has a positive effect on the thickness of the TrA muscle both in contraction and at rest, and also reduces the level of pain while improving quality of life.

The effect of therapeutic abdominal drawing-in maneuver using ultrasonography on lateral abdominal muscle thickness and balance

BACKGROUND

Lateral abdominal muscles control the lumbar region and this manages the stability of the trunk through co-contraction. Abdominal drawing-in maneuver (ADIM) is the basis method for spine stabilization to restore proper neuromuscular control.

OBJECTIVE

To investigate the effect of therapeutic abdominal drawing-in maneuver on abdominal muscle thickness and balance.

METHODS

Twenty healthy adults were divided into 2 groups. The experimental group performed a bridging exercise with ADIM whereas the control group performed a bridging exercise without ADIM. The exercise was conducted 3 times a week for 4 weeks. Ultrasonography was used to measure the thickness of abdominal muscles. Balance ability was evaluated using Tetrax device. The Wilcoxon signed ranks test for comparison of pre and post values and Mann Whitney U test for comparison between groups were used.

RESULTS

After 4 weeks, there was a significant difference in the thickness of TrA between groups (p< 0.05) whereas no significant difference in IO and EO (p> 0.05). In stability values, the experimental group showed significant changes in stability indexes of standing with eyes open (NO) and standing on the pillow with eyes closed (PC) after the exercise period and there was a significant difference in NO between two groups.

CONCLUSIONS

Performing the bridging exercise with abdominal drawing-in maneuver is a more effective way to strengthen the abdominal muscles and stabilize the body than bridging exercise only.

Relationship between transversus abdominis muscle thickness and urinary incontinence in females at 2 months postpartum

[Purpose] Urinary incontinence is a frequent postpartum complication. Thus, this study aimed to examine the associations of transversus abdominis muscle thicknesses at rest and during an abdominal drawing-in maneuver with urinary incontinence in females at 2 months postpartum. [Participants and Methods] The participants included 18 females at 2 months postpartum with or without urinary incontinence, and 10 nulliparous females as controls. Transversus abdominis thickness was measured at rest and during the abdominal drawing-in maneuver using diagnostic ultrasonography. The Japanese version of the International Consultation on Incontinence Questionnaire-Short Form was used to evaluate urinary incontinence. [Results] Females at 2 months postpartum were divided into groups with and without urinary incontinence according to questionnaire scores. The muscle thickness during the abdominal drawing-in maneuver contraction was significantly lower in those with urinary incontinence than in those without urinary incontinence and controls. [Conclusion] The results showed significantly reduced transversus abdominis thickness during contraction, which suggested reduced transversus abdominis strength in females with postpartum urinary incontinence. Thus, promoting synergistic contraction of the inner unit, including the transversus abdominis, in exercise therapy may be more effective for postpartum urinary incontinence.

Difference of the thickness and activation of trunk muscles during static stoop lift at different loads between subjects with and without low back pain

BACKGROUND

Patients suffering from low back pain (LBP) have been reported to alter muscle contraction strategies.

OBJECTIVE

To compare activity and thickness of the trunk muscles (external oblique (EO), internal oblique (IO), transversus abdominis (TrA), and lumbar multifidus (LM)) during static stoop lift at different lifting loads between the subjects with and without LBP.

METHODS

Twenty eight subjects with LBP and twenty eight healthy subjects were recruited. The stoop lifting was performed in three conditions in 0%, 10%, and 20% of body weight.

RESULTS

The activity of EO (F= 9.513) and IO (F= 7.781) was significantly increased with increasing lifting loads in subjects with LBP (p< 0.05) but not significantly in subjects without LBP. The activity of the LM (F= 124.980) was significantly increased in response to lifting loads in both groups (p< 0.05). The percent change of TrA (F= 8.797) and LM (F= 48.170) muscles thickness was significantly increased with increasing lifting loads in both groups (p< 0.05). The percent change of TrA (F= 3.780) and LM (F= 16.314) muscles thickness in subjects without LBP was greater than those in subjects with LBP at all three lifting loads (p< 0.05).

CONCLUSIONS

The results of this study suggest that more activation of EO in subjects with LBP may contribute to increase the compressive force on the lumbar spine during stoop lift. Also, less activation of TrA and LM in subjects with LBP may contribute to decrease the lumbar stabilization during stoop lift.

Changes in the contraction ratio of transversus abdominis and quality of life in patients after total hip replacement and three-compartment knee arthroplasty with implant posterior stabilization

Core stability is a reference term for the performance of the deep trunk muscles, which provide functional stability of the lumbopelvic area and control the human body in static and dynamic positions. The study group consisted of 30 patients between the age of 42 and 76 years (mean=61.4) after total hip arthroplasty (total hip replacement, Group I) and total knee arthroplasty (three-compartment arthroplasty with posterior stabilization of the implant - Group II). In 18 (60%) patients, hip endoprosthesis was performed, whereas in 12 (40%), three-compartment knee endoprosthesis with posterior stabilization has been implanted. In the study group, Rehabilitative Ultrasound Imaging (RUSI) of the transversus abdominis muscle thickness was conducted at rest and in contraction, the transversus abdominis activation ratio was specified, the SF-36 Life Quality Questionnaire was applied and a three-week treatment cycle was performed. The tests were carried out twice, i.e. before and after treatment. In the group of patients after total hip replacement, the transversus abdominis (TrA) contraction ratio before the beginning of the exercise programme was 0.79±0.06, and after its completion 0.9 ±0.02. The observed difference was statistically significant at p<0.001. In the group of patients after three-compartment knee arthroplasty, the TrA contraction ratio before the beginning of the exercise programme was 0.78±0.09, and after its completion0 0.91±0.02. The difference of these values was statistically significant at the level of p<0.05. The results of the SF-36 questionnaire in both groups indicate improvement in physical functioning. The observed difference was statistically significant at p<0.001. The performed three-week physiotherapy treatment in conjunction with deep muscle training increases the thickness of the TrA muscle during rest and contraction testing, and increases the transversus abdominis contraction ratio in Rehabilitative Ultrasound Imaging in the study groups. Furthermore, improvement in the level of physical functioning was observed within the studied groups.

Is abdominal hollowing exercise using real-time ultrasound imaging feedback helpful for selective strengthening of the transversus abdominis muscle?: A prospective, randomized, parallel-group, comparative study

Despite the importance of strengthening of the transversus abdominis (TrA) muscle in individuals with low back pain, the effect of real-time ultrasound imaging on maintenance in selective strengthening of abdominal hallowing exercise (AHE) performance has not been investigated. So, the aim of this study was to investigate the effects of AHE with real-time ultrasound imaging feedback on selective reinforcing the TrA muscle.Twenty healthy subjects were enrolled prospectively and randomized to train AHE for 2 weeks either by conventional feedback (group A) or by visual feedback from real-time ultrasound imaging additional to conventional feedback (group B). The changes in thickness of TrA, internal oblique abdominal muscle (IO), and external oblique abdominal muscle (EO) were measured using the ultrasonography. The changes in muscle activities of TrA-IO and EO were measured using surface electromyography.The thickness of TrA, IO, and EO muscles in resting was not significantly changed in both groups A and B. However, the ratio of root mean square (RMS) values of TrA-IO/EO muscles, which mirrors selective contraction of TRA-IO muscles against EO muscle, was significantly higher in group B than in group A.In healthy subjects, training with AHE using real-time ultrasound imaging feedback may be a useful additional method to conventional feedback for strengthening the TrA muscles selectively.

Changes in Muscle Thickness Across Positions on Ultrasound Imaging in Participants With or Without a History of Low Back Pain

CONTEXT

  Injury-prediction models have identified trunk muscle function as an identifiable factor for future injury. A history of low back pain (HxLBP) may also place athletes at increased risk for future low back pain. Reduced muscle thickness of the lumbar multifidus (LM) and transversus abdominis (TrA) has been reported among populations with clinical low back pain via ultrasound imaging in multiple positions. However, the roles of the LM and TrA in a more functional cohort and for injury prediction are still unknown.

OBJECTIVES

  To (1) assess the reliability of LM and TrA ultrasound measures, (2) compare changes in muscle thickness across positions between persons reporting or not reporting HxLBP, and (3) determine the ability to distinguish between groups.

DESIGN

  Cross-sectional study.

SETTING

  Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

  Participants were 34 people who did not report HxLBP (age = 22 ± 7 years, body mass index = 23.7 ± 2.7) and 25 people who reported HxLBP (age = 25 ± 10 years, body mass index = 24.0 ± 3.2).

MAIN OUTCOME MEASURE(S)

  Muscle thickness and changes in muscle thickness of the LM and TrA as shown on ultrasound imaging.

RESULTS

  Intraclass correlation coefficients ranged from 0.641 to 0.943 for all thickness measures and from 0 to 0.693 for all averaged thickness modulations bilaterally. Participants who reported HxLBP had voluntarily reduced TrA thickness modulations compared with those not reporting HxLBP ( P = .03), and the testing position influenced TrA thickness modulations ( P < .01). No differences were observed for LM thickness modulations between groups or positions ( P > .05). A tabletop cutoff value of 1.32 had a sensitivity of 0.640 and a specificity of 0.706, whereas a seated cutoff value of 1.18 had a sensitivity of 0.600 and a specificity of 0.647.

CONCLUSIONS

  In participants reporting HxLBP, TrA thickness modulations were lower and both tabletop and seated thickness modulations were able to distinguish reported HxLBP status. These findings suggest that TrA muscle function may be altered by HxLBP.

Differential Diagnosis in a Patient Presenting With Both Systemic and Neuromusculoskeletal Pathology: Resident's Case Problem

Study Design Resident's case problem. Background Patients presenting with multiple symptomatic areas pose a diagnostic challenge for the physical therapist. Though musculoskeletal and nonmusculoskeletal symptoms typically present separately, they can occur simultaneously and mimic each other. Consequently, the ability to differentiate between musculoskeletal and nonmusculoskeletal symptoms is an important skill for physical therapists. The purpose of this resident's case problem was to describe the clinical-reasoning process leading to medical and physical therapy management of a patient presenting with upper and lower back pain, bilateral radiating arm and leg pain, and abdominal pain. Diagnosis The patient was a 30-year-old woman referred to physical therapy for upper and lower back pain. A detailed history and thorough examination revealed that the patient had signs and symptoms consistent with a possible abdominal aortic aneurysm. She was referred for medical management and was diagnosed with symptomatic cholelithiasis. She subsequently had a cholecystectomy, which ultimately resolved her abdominal pain and reduced her pain in other areas significantly. Although many of her symptoms resolved postoperatively, her pain in other areas remained and was potentially musculoskeletal in origin. Following re-evaluation and 3 physical therapy treatments over a 2-month period, she was relatively symptom free at discharge and had achieved all functional rehabilitation goals. Discussion This resident's case problem provides an opportunity to discuss the differential diagnosis, clinical reasoning, and outcome of a patient who presented with both systemic and neuromusculoskeletal pathology. Level of Evidence Differential diagnosis, level 5. J Orthop Sports Phys Ther 2018;48(6):496-503. Epub 6 Feb 2018. doi:10.2519/jospt.2018.7652.

Ultrasound Assessment of the Transverse Abdominis During Functional Movement

OBJECTIVES

The traditional activation ratio divides contracted muscle thickness by resting muscle thickness while an abdominal draw-in maneuver is performed during hook lying. Ultrasound imaging during function, such as standing or gait, or peak knee flexion in a single-leg squat allows for further visualization of muscle activity. The goal of this study was to examine activation ratio calculations for transverse abdominis function in supine versus loaded conditions to determine the most informative normalization strategy for muscle activity based on thickness values.

METHODS

Transverse abdominis thickness was measured via ultrasound in 35 healthy participants under 4 different conditions. Comparisons were made between the traditional activation ratio tabletop, standing activation ratio (standing abdominal draw-in maneuver thickness/quiet standing thickness), and functional activation ratio (single-leg squat thickness/quiet standing thickness). Additionally, a cued activation ratio (single-leg squat with cued abdominal draw-in maneuver thickness/single-leg squat thickness) during the single-leg squat was obtained. Activation ratios of greater than 1.0 indicated that participants could activate the muscle during activity, and values were compared by analysis of variance.

RESULTS

The participants included 23 women and 12 men with a mean age ± SD of 21.3 ± 2.7 years, mass of 66.1 ± 14.4 kg, and height of 168.5 ± 10.1 cm. Activation ratios exceeded 1.0 in 94.3% for the traditional activation ratio, 85.7% for the standing activation ratio, 82.9% for the cued activation ratio, and 82.9% for the functional activation ratio. With groups defined as tabletop activated or not, the standing, cued, and functional activation ratios were all significantly different (all P < .05).

CONCLUSIONS

Normalizing muscle thickness to the corresponding functional position quiet value provides a useful functional activation ratio and may help clinicians better understand the transverse abdominis role during complex functional tasks. Assessment techniques using various formulas for activation ratios reveal that the muscle functions differently during weight bearing compared to traditional measures.

Serious Gaming to Support Exercise Therapy for Patients with Chronic Nonspecific Low Back Pain: A Feasibility Study

OBJECTIVE

To investigate the feasibility of a functional exercise program supported by serious gaming for patients with chronic nonspecific low back pain (LBP).

METHODS

Ten patients with chronic nonspecific LBP and an underlying motor control impairment were recruited. Subjects performed a partially supervised exercise program (36 sessions, 18 weeks) that included 30 minutes of general conditioning and 90 minutes of individually tailored functional motor control exercises (MCEs). Serious games (SGs) were used to (1) improve thoracolumbar dissociation and (2) to provide postural feedback during functional MCEs. The SGs were also available at home.

RESULTS

Treatment satisfaction and the scores on the credibility/expectancy questionnaire were good and did not change throughout the intervention. Patients remained motivated throughout the rehabilitation program and no serious adverse events were reported. Overall, participants indicated that the SGs helped them to perform the home exercises more correctly, and as a consequence, they felt more confident doing them. However, the time needed to set up the games was a barrier for home use and participants would have found it useful to receive postural feedback during daily life activities.

CONCLUSIONS

It is feasible to support a functional exercise program with SGs for patients with chronic nonspecific LBP, both in a supervised and a home environment. Time-efficiency and the integration of SGs in daily life activities are challenges that need to be addressed in the future.

Comparative Study of Abdominal Muscle Thickness on Ultrasonography in Healthy Adolescents and Patients With Low Back Pain

OBJECTIVES

Low back pain (LBP) is a common musculoskeletal disorder among different age groups, including adolescents. The purpose of this study was to compare the abdominal muscle thickness between healthy adolescents and those with LBP.

METHODS

One hundred sixty healthy high school adolescents and 80 high school adolescents with LBP participated in the study. All participants were asked to complete a demographic questionnaire and also a visual analog scale and the Oswestry Disability Questionnaire to evaluate the pain intensity and functional disability. Then abdominal muscle thickness was examined with ultrasonography.

RESULTS

The healthy high adolescents included 80 boys and 80 girls, and the adolescents with LBP included 40 boys and 40 girls. The results showed a significant difference between healthy adolescents and those with LBP in terms of abdominal muscle thickness (P < .05). Patients with LBP had smaller abdominal muscles compared with healthy adolescents. No significant difference was found between the groups in terms of the subcutaneous fat dimension (P > .05).

CONCLUSIONS

The thickness of abdominal muscles was lower in adolescents with LBP. Future studies with a larger sample and a wider age range are recommended to support the results of this study.

Effects of stabilization exercise using flexi-bar on functional disability and transverse abdominis thickness in patients with chronic low back pain

[Purpose] The purpose of this study is to examine the effects of lumbar stabilization exercises using flexi-bar (FB) on pain, functional disability, transverse abdominis muscle (TrA) activation capacity and thickness in patients with chronic low back pain (CLBP). [Subjects and Methods] Twenty-seven patients were randomly assigned to an experimental (14 patients performing stabilization exercises with flexi-bar (FB)) or control (13 patients performing stabilization exercises) group. The patients in both groups then underwent stabilization exercises with or without FB 30 min/day, 3 times a week, for 6 weeks. The main outcome measures were perceived disability based on the pain, Oswestry disability index (ODI), TrA activation capacity and thickness. [Results] Both groups showed improved ODI, VAS, and TrA activation capacity performed for 6 weeks in patients with CLBP, but all outcomes, except for TrA thickness, showed greater improvements in patients following stabilization exercises with FB than following stabilization exercises. [Conclusion] Based on the above results, lumbar stabilization exercises with FB could restoring pain, functional disability and improving TrA activation capacity in CLBP patients.

A multimodal physical therapy approach utilizing the Maitland concept in the management of a patient with cervical and lumbar radiculitis and Ehlers-Danlos syndrome-hypermobility type: A case report

The purpose of this case report is to present a multimodal approach for patient management using the Maitland concept framework for cervical and lumbar radiculitis with an underlying diagnosis of Ehlers-Danlos Syndrome-Hypermobility Type (EDS-HT). This case presents care guided by evidence, patient values, and rationale for the selected course of physical therapy treatment provided by therapist experience. A 35-year-old female with a 2-year history of worsening lumbar and cervical pain was referred to physical therapy to address these musculoskeletal issues concurrent with diagnostic testing for EDS. A multimodal approach including manual therapy, therapeutic exercise, postural and body mechanics education, and a home exercise program was used. The patient specific functional scale (PSFS) was used to gauge patient's perceived improvements which were demonstrated by increased scores at reevaluation and at discharge. Following the Maitland concept framework, the physical therapist was able to make sound clinical decisions by tracking the logical flow of constant patient assessment. A 10-month course of treatment designed to maximize recovery of function was successful with a chronic history of pain and the EDS-HT diagnosis. The role of education and empowering the patient is shown to be of utmost importance. Optimizing therapeutic outcomes long-term for this patient population requires maintaining a home exercise program, adaptation and modifications of work and lifestyle activities.

TRANSVERSUS ABDOMINIS ACTIVATION AND TIMING IMPROVES FOLLOWING CORE STABILITY TRAINING: A RANDOMIZED TRIAL

Background

Patients with non-specific low back pain (LBP) often present with a decrease in transversus abdominis (TrA) muscle activation and delayed onset of contraction with extremity movements, potentially contributing to recurrent LBP. Core stability is required for extremity movement and if the timing of when the TrA contracts is not corrected patients may continue to experience LBP.

Hypothesis/Purpose

The purpose of this study was to assess the effects of a four-week core stability rehabilitation program on TrA activation ratio and when the TrA initiates contraction during upper extremity movements in subjects with and without LBP. It was hypothesized that those with LBP would experience greater changes in TrA activation and onset of contraction by the TrA compared to the healthy group.

Study Design

Randomized Clinical Trial.

Methods

Forty-two participants volunteered (21 healthy and 21 LBP). Ultrasound imaging measured the TrA activation ratio and time of initial contraction of the TrA during upper extremity movement into flexion. Half of the healthy and LBP participants were assigned to the exercise group. Participants reported twice a week to the athletic training facility to complete an exercise progression of three exercises. After four weeks, all participants returned to have TrA activation and timing measured again.

Results

Pertaining to demographics, there were no differences between the healthy and LBP participants. There was a group interaction for both TrA activation ratio (p=.049) and onset of initial contraction (p=.008). Those in the exercise group showed an increase in TrA activation ratio (1.85 ± 0.09) compared to the control group (1.79 ± 0.08), as well as an improvement in the onset of contraction (2.07 ± 0.08 seconds) compared to the control group (2.23 ± 0.09 seconds) after the four-week rehabilitation program. Strong effect sizes for TrA activation ratio (0.71 [0.06-1.35]) and initial onset of TrA contraction (-1.88 [-2.63 - -1.11]) were found indicating clinical differences related to the interventions.

Conclusion

TrA activation and timing were altered following a four-week core stability program in people with and without LBP. Clinicians should consider incorporating these exercises for improving the function of the TrA.

Level of Evidence

Therapy, level 2b.

Pain intensity and abdominal muscle activation during walking in patients with low back pain: The STROBE study

Nonspecific low back pain (LBP) is a common musculoskeletal problem that is intensified during physical activity. Patients with LBP have been reported to change their abdominal muscle activity during walking; however, the effects of pain intensity, disability level, and fear-avoidance belief on this relationship have not been evaluated. Thus, we compared abdominal muscle activity in patients with LBP and asymptomatic controls, and assessed the impact of pain intensity, disability level, and fear-avoidance belief.Thirty patients with LBP divided into groups reporting low (LLBP) and high-pain intensity low back pain (HLBP), and 15 participants without LBP were recruited. LBP patients' self-reported pain intensity, disability, and fear-avoidance belief were recorded. To examine abdominal muscle activity (rectus abdominis [RA], internal [IO], and external oblique [EO] muscles) during walking, all subjects walked at a self-selected speed. Abdominal muscle activity (RA, IO, and EO) was compared among groups (LLBP, HLBP, and controls) in different phases of walking (double support vs swing). Relationships between abdominal muscle activity and clinical measures (pain intensity, disability, fear-avoidance belief) were analyzed using partial correlation analysis.Right IO muscle activity during walking was significantly decreased in LLBP and HLBP compared with controls in certain walking phase. Partial correlation coefficients showed significant correlations between fear-avoidance belief and right EO activity (r = .377, P < .05) and between disability index and left IO activity (r = .377, P < .05) in patients with LBP. No significant difference was found in abdominal muscle activity in walking between patients with LLBP and HLBP (P > .05).This study demonstrated decreased IO muscle activity during certain walking phases in LLBP and HLBP compared with asymptomatic participants. Although altered IO muscle activity during walking was observed in patients with LBP, no changes were found with other abdominal muscles (EO, RA). Thus, these results provide useful information about abdominal muscle activity during walking in patients with LBP.

Integrating Musculoskeletal Sonography Into Rehabilitation: Therapists' Experiences With Training and Implementation

Musculoskeletal sonography is rapidly extending beyond radiology; however, best practices for successful integration into new practice contexts are unknown. This study explored non-physician experiences with the processes of training and integration of musculoskeletal sonography into rehabilitation. Qualitative data were captured through multiple sources, and iterative thematic analysis was used to describe two occupational therapists' experiences. The dominant emerging theme was competency, in three domains: technical, procedural, and analytical. In addition, three practice considerations were illuminated: (a) understanding imaging within the dynamics of rehabilitation, (b) navigating nuances of interprofessional care, and (c) implications for post-professional training. Findings indicate that sonography training for rehabilitation providers requires multi-level competency development and consideration of practice complexities. These data lay a foundation on which to explore and develop best practices for incorporating sonographic imaging into the clinic as a means for engaging clients as active participants in the rehabilitation process to improve health and rehabilitation outcomes.

Tissue Deformation Index as a Reliable Measure of Lateral Abdominal Muscle Activation on M-Mode Sonography

The aim of this article is to present a novel method of evaluating the activity of lateral abdominal muscles using M-mode sonography. The method leads to calculation of the tissue deformation index, representing the percent change in lateral abdominal muscle thickness over time. The objectives of this study were as follows: (1) to establish the mean tissue deformation index values for individual lateral abdominal muscles; and (2) to establish the reliability of the tissue deformation index. In a group of 34 healthy young volunteers (mean age, 24.03 years; body mass, 68.89 kg; body height, 174.25 cm), the reflex response of the lateral abdominal muscles to postural perturbation in the form of rapid arm abduction was recorded in 2 series, with 6 repetitions each, and the tissue deformation index was calculated. The mean tissue deformation index values formed a gradient, increasing from deep to superficial lateral abdominal muscles: 0.06%/ms for transversus abdominis, 0.11%/ms for oblique internal, and 0.16 for oblique external muscles. The tissue deformation index values differed significantly among individual lateral abdominal muscles (all paired comparisons, P < .001). Three repeated measurements are sufficient to achieve good intra-rater reliability of the tissue deformation index (intraclass correlation coefficient, > 0.8).

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.

Movement amplitude on the Functional Re-adaptive Exercise Device: deep spinal muscle activity and movement control

PURPOSE

Lumbar multifidus (LM) and transversus abdominis (TrA) show altered motor control, and LM is atrophied, in people with low-back pain (LBP). The Functional Re-adaptive Exercise Device (FRED) involves cyclical lower-limb movement against minimal resistance in an upright posture. It has been shown to recruit LM and TrA automatically, and may have potential as an intervention for non-specific LBP. However, no studies have yet investigated the effects of changes in FRED movement amplitude on the activity of these muscles. This study aimed to assess the effects of different FRED movement amplitudes on LM and TrA muscle thickness and movement variability, to inform an evidence-based exercise prescription.

METHODS

Lumbar multifidus and TrA thickness of eight healthy male volunteers were examined using ultrasound imaging during FRED exercise, normalised to rest at four different movement amplitudes. Movement variability was also measured. Magnitude-based inferences were used to compare each amplitude.

RESULTS

Exercise at all amplitudes recruited LM and TrA more than rest, with thickness increases of approximately 5 and 1 mm, respectively. Larger amplitudes also caused increased TrA thickness, LM and TrA muscle thickness variability and movement variability. The data suggests that all amplitudes are useful for recruiting LM and TrA.

CONCLUSIONS

A progressive training protocol should start in the smallest amplitude, increasing the setting once participants can maintain a consistent movement speed, to continue to challenge the motor control system.

Assessment of the abdominal muscles at rest and during abdominal drawing-in manoeuvre in adolescent physically active girls: A case-control study

BACKGROUND

An impact of regular physical activity (RPA) on the abdominal muscles may be significant when comparing various symptomatic groups. However, there is lack comprehensive information in this field. The objective of this study was to assess the lateral abdominal wall at rest and during abdominal drawing-in manoeuvre in adolescent physically active girls in different body positions.

METHODS

One hundred and forty-four female students, 13-17 years of age, participated in the study. Participants were divided into 2 groups based on a physical activity (PA) statement. Measurements of the thickness of the abdominal muscles at rest and during abdominal drawing-in manoeuvre were made in the supine and standing positions by ultrasound imaging.

RESULTS

Compared to the control group, activities of the obliquus internus and transversus abdominis muscles were higher in the regular PA group by 8.9% (95%CI: 3.1-14.7) and 36% (95%CI: 19.1-47.5), respectively. In the RPA group, the transversus abdominis preferential activation ratio was greater by 0.03 (95%CI: 0.01-0.04), and the contraction ratio was greater by a mean value of 0.35 (95%CI: 0.18-0.46).

CONCLUSION

RPA does not have any effect on the resting thickness of the abdominal muscles in the supine and standing positions. Girls performing RPA have a greater ability to perform an independent activation and greater contractions of the transversus abdominis.

Reliability and Precision of Sonography of the Lumbar Multifidus and Transversus Abdominis During Dynamic Activities

OBJECTIVES

To determine the intrarater reliability and precision of lumbar multifidus and transversus abdominis thickness measurements using freehand sonography in a range of static and dynamic conditions.

METHODS

Fifteen asymptomatic participants performed a range of exercises while sonography was used to measure absolute muscle thickness and changes in muscle thickness from rest. Exercise conditions included the abdominal drawing-in maneuver, active straight leg raise, contralateral arm lift, both unloaded and loaded, treadmill walking, and using the Functional Readaptive Exercise Device. Intraday and interday reliability was assessed by intraclass correlation coefficients, and the standard error of measurement was used to assess measurement precision.

RESULTS

Good to excellent reliability was achieved for absolute transversus abdominis and lumbar multifidus thickness in all conditions. Measurement precision for absolute lumbar multifidus thickness was ≤2.8 mm for the unloaded contralateral arm lift, ≤1.8 mm for the loaded contralateral arm lift, ≤3.1 mm for treadmill walking, and ≤3.8 mm for the Functional Readaptive Exercise Device; for absolute transversus abdominis thickness, precision was ≤0.6 mm for the abdominal drawing-in maneuver, ≤0.5 mm for the active straight leg raise, ≤0.7 mm for treadmill walking, and ≤0.5 mm for the Functional Readaptive Exercise Device. Good to excellent reliability was achieved for relative transversus abdominis and lumbar multifidus thickness in all conditions. Measurement precision for relative lumbar multifidus thickness was ≤3.7% for the unloaded contralateral arm lift, ≤3.8% for the loaded contralateral arm lift, ≤6.3% for treadmill walking, and ≤7.6% for the Functional Readaptive Exercise Device; for relative transversus abdominis thickness, precision was ≤13.6% for the abdominal drawing-in maneuver, ≤6.9% for the active straight leg raise, ≤11.1% for treadmill walking, and ≤7.2% for the Functional Readaptive Exercise Device.

CONCLUSIONS

Acceptable reliability and precision of measurement is achieved for absolute and relative measures of deep spinal muscle thickness using freehand sonography in relatively static and dynamic exercises.