What is a Suitable Pressure for the Abdominal Drawing-in Maneuver in the Supine Position Using a Pressure Biofeedback Unit?

The effect of treadmill walk with abdominal bracing versus usual care on functional limitation and fear-avoidance behaviours in the management of non-specific low back pain—a randomized control study

Background

The use of a combined abdominal bracing technique concurrently with treadmill walking exercise seems not to have been widely investigated, The use of either abdominal bracing and treadmill walk as a single individual method of treatment has proven to be of immense benefit in athletic training and amelioration of pain and functional limitation among different age groups suffering from chronic low back pain. Thus, the need to investigate whether the combination of abdominal bracing and treadmill walking would produce greater benefits than when the exercises are carried out in isolation in the management of chronic low back pain patients.

Study design

The study was a randomized control.

Participants

Thirty-three participants who met the inclusion criteria with age from 18 to 65 participated in the study.

Aim

This study aimed to compare the effects of treadmill walk with and without abdominal bracing versus usual care on pain, functional limitation and fear-avoidance behaviours among patients with non-specific chronic low back pain.

Methods

Thirty-three non-specific chronic low back pain (NSCLBP) patients were randomized into three groups treadmill walk without abdominal bracing (TWW), treadmill walk with abdominal bracing (TWAB) and usual care (UC). Interventions were carried out for 6 weeks.

Outcome measure

Pre and post-intervention scores of pain intensity, functional limitation, and fear-avoidance belief were assessed with box numerical pain rating scales, Oswestry disability index and Fear-Avoidance Belief Questionnaire, respectively.

Results

Pre-intervention scores of pain intensity functional disability and fear-avoidance belief did not show significant differences among the groups (P >0.05). Within-group analysis with paired t-test showed that pain intensity and functional limitation were significantly reduced after 6 weeks of intervention among the 3 groups. Fear-avoidance belief recorded statistical reduction among the 2 treadmill procedures (TWAB and TWW) groups (P<0.05) but not in the usual care groups (P>0.05). Participants in the TWW group showed greater improvement than those in TWAB in terms of reduction in pain intensity (24.17±16.49), functional limitation (7.00±5.97, P = 0.001) and fear- avoidance (30.83±17.90, P = 0.003)

Conclusion

Treadmill walk with and without abdominal bracing as well as usual care could be effective in reducing pain. However, treadmill walk without abdominal bracing was more effective in improving back function in terms of reduction in pain intensity, functional limitation (as reported by the Oswestry scale) and reducing fear-avoidance behaviour (as reported by fear-avoidance belief scores).

Trial registration

PACTR, PACTR201910691645076. Registered on 22 October 2019.

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

OBJECTIVE

The aim of this study was to compare the effects of verbal, tactile-verbal, and visual feedback on muscle activation of the lumbar stabilizers relative to extremity movers during an abdominal drawing-in maneuver when feedback is withheld.

METHODS

This quasi-experimental study equally divided 54 healthy adults into 3 feedback groups (verbal, tactile-verbal, and visual) who trained twice per week over a 4-week period to perform supine abdominal drawing-in maneuvers. The percentage of maximum voluntary isometric contraction of rectus abdominis, multifidus (MF), erector spinae, and hamstrings (HS) as an outcome measure was acquired using surface electromyography. A 2-way factorial analysis of variance with bootstrapping allowed for comparison of post-pre difference scores across the interaction of feedback and muscle groups.

RESULTS

Hamstring activation decreased in those receiving tactile-verbal feedback relative to an increase in participants given visual feedback. Furthermore, when using verbal feedback, HS activity increased relative to a decline in rectus abdominis, and when presenting visual feedback, HS activity increased relative to a decrease in MF. However, no post-pre changes were seen across muscles with tactile-verbal feedback.

CONCLUSION

Although tactile-verbal feedback did not increase MF recruitment, it produced less HS activity than visual feedback. Undesirable HS recruitment may reflect boredom or feedback dependency.

An Evaluation of an Innovative Exercise to Relieve Chronic Low Back Pain in Sedentary Workers

OBJECTIVE

The purpose of the study was to examine the effectiveness of a novel supported dynamic lumbar extension with the abdominal drawing-in maneuver (ADIM) technique on stature change, deep abdominal muscle activity, trunk muscle fatigue, and pain intensity during prolonged sitting in chronic low back pain (CLBP) participants.

BACKGROUND

Prolonged sitting can cause trunk muscle fatigue from continuous contraction of deep trunk muscles in seated postures. Deficiency of activity of deep muscles can reduce muscular support of the spine, causing stress on spinal structures, which could result in pain.

METHOD

Thirty participants with CLBP were randomly allocated: (a) control-sitting without exercise, and (b) intervention-supported dynamic lumbar extension with the ADIM technique.

RESULTS

Compared to the intervention condition, the control condition demonstrated significantly greater deterioration in stature change, increased levels of deep trunk muscle fatigue, and an increase in pain during prolonged sitting.

CONCLUSION

The supported dynamic lumbar extension with the ADIM technique appears to provide a protective effect on detrimental stature change and deep trunk muscle fatigue. In addition, it prevented an increase in pain intensity during prolonged sitting in people with CLBP.

APPLICATION

Sedentary behavior harms health, particularly affecting the lower back. Clinicians can use the intervention to induce dynamic lumbar movement, and this exercise can maintain deep trunk muscle activity during prolonged sitting, thereby helping to prevent low back pain (LBP) problems.

DIFFERENTIAL EFFECTS OF THE ABDOMINAL DRAW-IN MANEUVER IN DIFFERENT POSITIONS ON MUSCLE THICKNESS AND BALANCE RATIO IN NONSYMPTOMATIC ADULTS

Core stability mediated by the abdominal draw-in maneuver (ADIM) has been proven to be an important component of neuromuscular motor control before movement. However, no previous research has investigated which position is best for performing ADIM to achieve optimal core stability. This study aimed to define the effectiveness of performing ADIM in three different positions (prone, supine, and hook lying) on abdominal muscle thickness in nonsymptomatic participants. In total, 30 nonsymptomatic participants (mean age: [Formula: see text] years) were randomly assigned to a trial sequence using the random sequence method. The clinical outcomes were transverse abdominis (TrA), external oblique (EO), and internal oblique (IO) muscle thicknesses, which were evaluated using ultrasonography (US) and muscle thickness balance ratio. One-way repeated-measures analysis of variance (ANOVA) was used to evaluate the US data to determine if the resulting TrA, IO, and EO muscle thicknesses from the three different positions were statistically significant. Bonferroni correction was used as a post hoc test if statistical significance was found. The [Formula: see text] value was set to 0.013. One-way ANOVA showed a significant difference in the thickness of the TrA, IO, and EO muscles resulting from the different positions ([Formula: see text]). Post hoc analysis using Bonferroni correction revealed that the prone position resulted in greater changes than the supine and hook-lying positions ([Formula: see text], respectively). ANOVA did not show a significant change in the TrA, IO, and EO muscle thickness balance ratios ([Formula: see text], 0.44, and 0.59, respectively). The results provide innovative clinical evidence that performing ADIM in different positions (prone, supine, and hook lying) has different effects on abdominal muscle thickness in nonsymptomatic participants.

Effects of the abdominal drawing-in maneuver on hamstring rotational activity and pelvic stability in females

BACKGROUND

The medial hamstring (MH) and lateral hamstring (LH) can be selectively trained through tibial internal and external rotation during prone knee flexion. However, no study has identified how a combined tibial rotation and lumbo-pelvic stability strategy influences MH and LH muscle activities.

OBJECTIVE

To investigate the combined effects of tibial rotation and the abdominal drawing-in maneuver (ADIM) on MH and LH muscle activities as well as pelvic rotation during prone knee flexion.

METHODS

Fifteen female volunteers performed prone knee flexion with tibial internal and external rotation, with and without the ADIM. Under each condition, MH and LH muscle activities were measured by surface electromyography (EMG), and the pelvic rotation angle by a smartphone inclinometer application.

RESULTS

The results showed increased MH (without the ADIM: p< 0.001, effect size (d) = 2.05; with the ADIM: p< 0.001, d= 1.71) and LH (without the ADIM: p< 0.001, d= 1.64; with the ADIM: p= 0.001, d= 1.58) muscle activities under internal and external tibial rotation, respectively. However, addition of the ADIM led to increased MH (internal tibial rotation: p= 0.001, d= 0.67; external tibial rotation: p= 0.019, d= 0.45) and LH (internal tibial rotation: p= 0.003, d= 0.79; external tibial rotation: p< 0.001, d= 1.05) muscle activities combined with reduced pelvic rotation (internal tibial rotation: p< 0.001, d= 3.45; external tibial rotation: p< 0.001, d= 3.01) during prone knee flexion.

CONCLUSIONS

These findings suggest that the ADIM could be useful for reducing compensatory pelvic rotation and enhancing selective muscle activation in the MH and LH, according to the direction of tibial rotation, during prone knee flexion.

Clinical utility of ultrasonography imaging in musculoskeletal conditions: A Systematic review and Meta-analysis

Optimising ultrasonography imaging (UI) applications for clients is a highly specific and sensitive add-on method. The aim of this meta-analysis was to systematically evaluate the clinical utilisation of UI in musculoskeletal conditions by rehabilitation providers in the past decade. Two reviewers independently assessed relevant research articles from five databases electronically (Medline, Cochrane Library, EMBASE, ProQuest, EBSCO) and screened titles and abstracts based on predefined eligibility criteria (2010- 2020). A total of 147 articles were screened for eligibility by two reviewers independently, and any disagreements were resolved by another reviewer using Rayyan QCRI software. Ninety-seven duplicates were removed, and after excluding 21 studies, 16 randomized controlled trials were included and full texts retrieved. Data were synthesised using Revman 5.4 software for qualitative analysis and risk-of-bias assessment. Four similar studies were statistically analysed for heterogeneity of abdominal muscle contraction ratios. Two interventional studies were also analysed to assess the effect of feedback. The diagnostic application of UI was investigated using a consistent amount of literature, though from a rehabilitation perspective the literature is inconclusive. The clinical utility of UI in rehabilitation by physical therapists is conclusive and has potential to advance clinical practice. Further well-designed randomized controlled trials minimising selection biases will help improve the quality in this domain. Critical reflection, clinical reasoning, and mutual goal setting will help practising physical therapists to scrutinize the clinical practice more objectively.

The immediate effect of the abdominal drawing-in maneuver technique on stature change in seated sedentary workers with chronic low back pain

Many studies have measured stature change arising from loads imposed on the spine during sitting. To improve stature recovery, it is important to stabilise the lumbar spine and compensate forces from the upper body. The abdominal drawing-in maneuver (ADIM) technique has been found to mainly activate deep trunk muscles. The purpose of this study was to determine whether activation of deep trunk muscles by the ADIM technique could immediately improve stature recovery during prolonged sitting. Twenty-four patients with chronic low back pain (CLBP) were randomly allocated into different orders of experimental conditions: control (sitting without ADIM technique) and intervention conditions (sitting with ADIM technique). The latter condition required participants to complete ADIM technique for 1 min and repeat it three times throughout 41 min prolonged sitting time. Stature recovery was improved by 3.292 mm in the intervention condition compared with control condition (p-value = 0.001). Our finding demonstrated that ADIM technique improved stature recovery. Practitioner Summary: Prolonged sitting seemingly harms sedentary workers' health, particularly affecting the lower back. Activation of deep trunk muscles using abdominal drawing-in maneuver technique can promote spinal recovery. Clinicians can teach abdominal drawing-in maneuver technique to activate deep trunk muscles in chronic low back pain, thereby promoting self-management of seated stature recovery. Abbrevations: ADIM: abdominal drawing-in maneuver; RA: rectus abdominis; ICLT: iliocostalis lumborum pars thoracis; LM: lumbar multifidus; TrA: transversus abdominis; IO: internal oblique; CLBP: chronic low back pain; LBP: low back pain; RMDQ: Roland Morris disability questionnaire; NRS: numerical rating scale.

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

BACKGROUND AND PURPOSE

The transversus abdominis (TrA) is a key muscle for lumbar stabilization and is often retrained in physical therapy. Feedback tools, such as the pressure biofeedback unit (PBU) and rehabilitative ultrasound imaging (RUSI), are frequently used by physical therapists to train their patients and improve their patients' ability to contract this muscle. However, the effect of these tools in rehabilitating the TrA in older adults remains to be demonstrated, as is their efficiency in transferring the skill of recruiting the TrA from a supine position to a standing position.The objective of the study was to compare the immediate effectiveness of the PBU and RUSI to reeducate the TrA muscle in a population of asymptomatic older adults (without pain).

METHODS

Forty participants were randomized into 2 groups (RUSI or PBU). The intervention included a training session involving 15 TrA contractions held for 10 seconds with the corresponding feedback device. The dependent variable, TrA thickness (a muscle activation indicator), was measured using ultrasound images before and after the intervention in a supine and standing position. Nonparametric analyses were used for inter- and intragroup comparisons.

RESULTS AND DISCUSSION

The results showed no between-group differences in TrA activation ratio (AR) in the supine or standing position (supine AR: TrA RUSI thickness change P = .53 vs PBU thickness change P = .73, comparison between groups P = .51; standing AR: TrA RUSI thickness change P = .003 vs PBU thickness change P = .10; comparison between groups P = .61). However, the change in TrA thickness compared to the other abdominal wall muscles in a standing position was significantly less post-intervention for the RUSI group only (RUSI P = .006 vs PBU P = .72). Both groups remained similar post-intervention for this outcome (P = .20).

CONCLUSIONS

Neither the RUSI nor the PBU seems to have the desired effect on the activation of TrA in asymptomatic older adults.

The immediate effect of the abdominal drawing-in maneuver technique on stature change in seated sedentary workers with chronic low back pain

Many studies have measured stature change arising from loads imposed on the spine during sitting. To improve stature recovery, it is important to stabilise the lumbar spine and compensate forces from the upper body. The abdominal drawing-in maneuver (ADIM) technique has been found to mainly activate deep trunk muscles. The purpose of this study was to determine whether activation of deep trunk muscles by the ADIM technique could immediately improve stature recovery during prolonged sitting. Twenty-four patients with chronic low back pain (CLBP) were randomly allocated into different orders of experimental conditions: control (sitting without ADIM technique) and intervention conditions (sitting with ADIM technique). The latter condition required participants to complete ADIM technique for 1 min and repeat it three times throughout 41 min prolonged sitting time. Stature recovery was improved by 3.292 mm in the intervention condition compared with control condition (p-value = 0.001). Our finding demonstrated that ADIM technique improved stature recovery. Practitioner Summary: Prolonged sitting seemingly harms sedentary workers' health, particularly affecting the lower back. Activation of deep trunk muscles using abdominal drawing-in maneuver technique can promote spinal recovery. Clinicians can teach abdominal drawing-in maneuver technique to activate deep trunk muscles in chronic low back pain, thereby promoting self-management of seated stature recovery. Abbrevations: ADIM: abdominal drawing-in maneuver; RA: rectus abdominis; ICLT: iliocostalis lumborum pars thoracis; LM: lumbar multifidus; TrA: transversus abdominis; IO: internal oblique; CLBP: chronic low back pain; LBP: low back pain; RMDQ: Roland Morris disability questionnaire; NRS: numerical rating scale.

An International Classification of Function, Disability and Health (ICF)-based investigation of movement impairment in women with pelvic organ prolapse

Background

There is little evidence on movement impairment of the abdominal and pelvic floor muscles (PFM) in women with pelvic organ prolapse (POP).

Objectives

The aim of this study was to determine the movement impairments and interactions between the PFM and abdominal muscles in POP.

Method

The PFM and abdominal muscles of 100 conveniently sampled South African women with POP were assessed by ultrasonography, electromyography (EMG), the PERFECT scale, Sahrmann scale and a Pressure Biofeedback Unit (PBU). A demographic questionnaire determined contextual factors (exercise and medical history) and Visual Faces Scale pain intensities. Data were analysed descriptively and with Spearman and Pearson correlation coefficients.

Results

Participants (59 ± 9.31 years) were mostly unemployed (80%), physically inactive (85%), with comorbidities, heart or vascular disease, hypothyroidism and depression. The mean levator hiatus at rest (56.38 mm, standard deviation [SD] 9.95), thickness (5.1 mm, SD 1.41), amount of movement (4.28 mm, SD 6.84), strength (level 1.89, SD 1.13) and endurance (4.04 s, SD 3.32) of the PFM indicated dysfunction. Median values of zero were found for the Sahrmann scale (interquartile [IQ] range [0–1]) and PBU (IQ range [0–2]) and 10.95 µV for abdominal EMG (IQ range [7.9–17.8]). Pelvic floor muscle strength, endurance, movement and EMG activity correlation was fair (r > 0.4, p < 0.001), as was PFM strength, endurance and abdominal muscle function (r > 0.4, p < 0.05).

Conclusion

Movement impairment of local and global stability and mobility functions of PFM and abdominal muscles was present, as well as correlations between these functions. Addressing these impairments may affect the identified contextual factors (socio-economic, psychological and lifestyle factors) and the possible activity limitations and participation restrictions in patients with POP. Further research is needed to investigate these interactions.

Clinical implications

The findings suggest that assessment and management of patients with POP might need to be based on a comprehensive neuro-musculoskeletal assessment and a holistic approach. Standardised protocols for patients with pelvic floor dysfunction (PFD) should therefore be used with caution. Randomised controlled trials should investigate patient-specific and holistic intervention approaches.

Correlations between core muscle geometry, pain intensity, functional disability and postural balance in patients with nonspecific mechanical low back pain

Patients with low back pain (LBP) have reduced core muscle geometry and impaired postural balance. Impaired trunk control was shown to be associated with poor balance and limited functional mobility in these patients. However, the relationship between muscle geometry and postural balance is unclear. This study aimed to determine the correlation of core muscle geometry with pain intensity, functional disability and postural balance in patients with chronic nonspecific mechanical LBP. Thirty patients aged 20-50 years were enrolled. Ultrasound imaging was used to assess their muscle geometry. The participants completed a numerical rating scale (NRS) for pain severity, and the Persian version of the Roland-Morris Disability Questionnaire (PRMDQ). To estimate static balance, they were asked to perform the single leg stance test. Dynamic balance was assessed with the Y-balance test. Significant correlations were found between NRS scores and bilateral multifidus cross-sectional area during rest (r ≥ - 0.31, P ≤ 0.04) and contraction (r ≥ - 0.37, P ≤ 0.02). NRS scores correlated significantly with bilateral multifidus thickness during rest (r ≥ - 0.31, P ≤ 0.04) and contraction (r ≥ - 0.28, P ≤ 0.04). Significant correlations were also observed for PRMDQ scores with thickness (r ≥ - 0.35, P = 0.04) and cross-sectional area of the multifidus muscles (r ≥ - 0.33, P = 0.04) bilaterally during contraction. A significant correlation was found between Y-balance scores and right abdominal muscle thickness during rest and contraction (r ≥ 0.34, P ≤ 0.04). Core muscle geometry correlated with pain, functional disability indices and dynamic balance in these patients.

Effects of Qigong practice in office workers with chronic non-specific low back pain: A randomized control trial

OBJECTIVE

To investigate the effects of Qigong practice, Guan Yin Zi Zai Gong level 1, compared with a waiting list control group among office workers with chronic nonspecific low back pain (CNLBP).

METHODS

A randomized controlled trial was conducted at offices in the Bangkok Metropolitan Region. Seventy-two office workers with CNLBP were screened for inclusion/exclusion criteria (age 20-40 years; sitting period more than 4 h per day) and were allocated randomly into two groups: the Qigong and waiting list groups (n = 36 each). The participants in the Qigong group took a Qigong practice class (Guan Yin Zi Zai Gong level 1) for one hour per week for six weeks at their workstation. The participants were encouraged to conduct the Qigong exercise at home every day. The waiting list group received general advice regarding low back pain management. The primary outcomes were pain intensity, measured by the visual analog scale, and back functional disability, measured by the Roland and Morris Disability Questionnaire. The secondary outcomes were back range of motion, core stability performance index, heart rate, respiratory rate, the Srithanya Stress Scale (ST-5), and the global perceived effect (GPE) questionnaire.

RESULTS

Compared to the baseline, participants in the Qigong group experienced significantly decreased pain intensity and back functional disability. No statistically significant difference in these parameters was found in the waiting list group. Comparing the two groups, Qigong exercise significantly improved pain intensity, back functional impairment, range of motion, core muscle strength, heart rate, respiratory rate, and mental status. The Qigong group also had a significantly higher global outcome satisfaction than the waiting list group.

CONCLUSION

Qigong practice is an option for treatment of CNLBP in office workers.

Comparison of abdominal muscle activity during abdominal drawing-in maneuver combined with irradiation variations

Many experts have used an indirect method for enhancing strength and performance of muscles in clinical practice. The indirect method, which called an irradiation is a basic procedure of proprioceptive neuromuscular facilitation, there is little research related the effects of irradiation. This study investigated abdominal muscle activity during abdominal drawing-in maneuver (ADIM) combined with irradiation variations. The study recruited 42 healthy, young adults who were divided randomly into three groups according to which intervention they received. The first group performed the ADIM combined with coactivation of the pelvic floor muscle. The second group performed the ADIM combined with the irradiation resulting from dorsiflexion of the ankle. The third group performed the ADIM combined with the irradiation resulting from bilateral arm extension. Electromyography data were collected from the rectus abdominis, external oblique abdominis, and transversus abdominis/internal oblique abdominis (TrA/IO) muscles during ADIM combined with irradiation variations. There were significant differences in the abdominal muscle activity and the preferential contraction ratio of the TrA/IO among the three groups (P<0.05). ADIM combined with irradiation resulting from bilateral arm extension may be effective for enhancing the deep and superficial abdominal muscles of healthy people and athletes. The ADIM without the irradiation is advantageous for recovering motor control of the TrA/IO.

Comparison of abdominal muscle thickness according to feedback method used during abdominal hollowing exercise

[Purpose] This study was intended to examine the most effective feedback method for contracting the musculus transversus abdominis muscle by using basic training, a pressure biofeedback unit, and real-time ultrasonographic imaging during abdominal hollowing exercise training. [Subjects and Methods] The subjects in this study were 30 healthy young students in their twenties. Thirty subjects were divided randomly and equally into the basic training, the pressure biofeedback unit, and real-time ultrasonographic imaging groups. All of the subjects received abdominal hollowing exercise training for 15 minutes. The subjects in the pressure biofeedback unit group were trained by using a pressure biofeedback unit. Those in the real-time ultrasonographic imaging group received training with monitoring of possible contraction of their musculus transversus abdominis muscles on ultrasonography. [Results] In all the three groups, the musculus transversus abdominis became significantly thicker, but more significantly in the real-time ultrasonographic imaging group than in the basic training group. [Conclusion] The feedback method using real-time ultrasonographic imaging may be more effective in thickening the musculus transversus abdominis muscle during exercise than the traditional feedback method with manual contact only. However, it is insufficient in terms of overall qualitative improvement of exercise outcome.

Reliability of ultrasound in combination with surface electromyogram for evaluating the activity of abdominal muscles in individuals with and without low back pain

This study investigated the reliability of ultrasound in combination with surface electromyogram (EMG) for evaluating the activity of the abdominal muscles in individuals with and without low back pain during the abdominal drawing-in maneuver (ADIM). The study recruited ten individuals with or without low back pain, respectively. While the participants were performing the ADIM, the activities of the transversus abdominis (TrA) and the internal oblique (IO) were measured using ultra-sound, while the activities of the external oblique (EO) and the rectus abdominis (RA) were measured using surface EMG. Intra-class correlation coefficients (ICC) were used to verify the inter-rater reliability of ultrasound in combination with surface EMG at rest and during the ADIM, and Bland-Altman plots were used to verify intra-rater reliability. The inter-rater reliability for the two groups at rest and during the ADIM was excellent (ICC_2,1 = 0.77–0.95). In the Bland-Altman plots, the mean differences and 95% limits of agreement in the abdominal muscles of the two groups at rest were −0.03∼0.03 mm (−0.66 to 0.60 mm) and −0.12∼ −0.05 (−0.58 to 0.48% MVIC), respectively. The mean differences and 95% limits of agreement in the abdominal muscles of the two groups during the ADIM were −0.04∼0.02 mm (−0.73 to 0.65 mm) and −0.19∼0.05% MVIC (−1.24 to 1.34% MVIC), respectively. The ultrasound in combination with surface EMG showed excellent inter-rater and intra-rater reliability at rest and during the ADIM.

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.