Background: Chronic low back pain (CLBP) causes morphological changes in muscles, reduces muscle strength, endurance and flexibility, negatively affects lumbar stability, and limits functional activity. Plank exercise strengthens core muscles, activates abdominal muscles, and improves intra-abdominal pressure to stabilize the trunk in patients with CLBP. Objects: We investigated the effect of plank exercise on abdominal muscle thickness and disability in patients with CLBP. Methods: We classified 33 subjects into 2 groups: An experimental (n1=17) and a control group (n2=16). Patients in the experimental group participated in plank exercise and those in the control group participated in stretching exercise. Patients in both groups attended 20-minute exercise sessions thrice a week for 4 weeks. Abdominal muscle thickness in each subject was evaluated ultrasonographically, and disabilities were assessed using the Oswestry disability index (ODI). Results: Four weeks later, abdominal muscle thickness showed a significant increase over baseline values in both groups (p<.05). Patients in the experimental group reported a more significant increase in the thickness of the external oblique muscle than that in the control group (p<.05). ODI scores in the experimental group were significantly lower after intervention than before intervention (p<.05). Conclusion: Plank exercise increases the thickness of the external oblique muscle and reduces disability secondary to mild CLBP. Therefore, plank exercise is needed to improve lumbar stability and functional activity in patients with mild CLBP.

Background: The continuous co-contraction of the trunk muscles through trunk stabilization exercises is important to patients with lumbar spinal stenosis (LSS). However, intentional abdominal muscle contraction (IAMC) for trunk stabilization has been used only for specific training in the treatment room. Objects: The purpose of this study was to provide feedback to adults with LSS to enable IAMC during activities of daily living (ADLs). Methods: The participants with spinal stenosis were divided into an experimental group of 15 adults and a control group of 16 adults. Electromyographic signals were measured while the subjects kept their both hands held up at 90°. The measured muscles were the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and erector spinae (ES). Pelvic tilt was measured using a digital pelvic inclinometer. The degree of pain was measured using the visual analogue scale (VAS) and functional capacity was measured using the Korean version of the Oswestry disability index (KODI). Results: While the experimental group showed statistically significantly higher activities in the RA, EO, and IO after the intervention compared with the control group. Pelvic tilt was significantly decreased only in the experimental group. Both the experimental and control groups exhibited statistically significant declines in the VAS and KODI (p<.01). In terms of the levels of changes, the experimental group exhibited a statistically significant larger decline only in the VAS and the pelvic tilt when compared with the control group (p<.05). Conclusions: The subjects could stabilize their trunks, and relieve their pain and dysfunctions and reduce pelvic tilt by learning abdominal muscle contraction during ADLs.

This study aimed to investigate the effect of the abdominal drawing-in maneuver (ADIM) and abdominal expansion maneuver (AEM) on trunk stabilization, as well as trunk muscle activities and differences in quadruple visual analogue scale, Korean Oswestry Disability Index, and Fear Avoidance Beliefs Questionnaire scores, in patients with chronic low back pain and lumbar spine instability. To increase intra-abdominal pressure during the trunk stabilization exercise, the technique of pushing the abdomen out using diaphragmatic abdominal breathing suggested by Pavel Koral was used, which we termed the AEM. Fifty patients who tested positive on more than three of the five lumbar spine instability tests were separated from 138 patients with chronic low back pain of these patients, 16 were placed in the control group (trunk stabilization exercise), 17 were placed in the ADIM group (trunk stabilization exercise with ADIM), and 17 were placed in the AEM group (trunk stabilization exercise with AEM). Each group participated in the study for 30 minutes three times weekly for 4 weeks. Surface electromyography was used to measure the trunk muscle activities during the kneeling forward and supine bridging positions, and one-way repeated analysis of variance was used to determine the statistical significance of the trunk muscle activities in the rectus abdominis, internal oblique (IO), erector spinae, and multifidus (MF) muscles. The ADIM and AEM groups showed relatively larger improvements in psychosocial and functional disability level than control group. There were significant changes among the three groups, those from the measured values of the AEM group was significantly higher than the other two groups in changes in IO and MF trunk muscle activities (p＜05). This finding demonstrates that trunk stabilization exercises with AEM is more effective than ADIM for increasing trunk deep muscle activity of chronic low back pain patients with lumbar spine instability.

The aim of this study was to investigate the effect of abdominal drawing-in maneuver (ADIM) on peak exploratory flow (PEF), forced exploratory volume in 1 second (FEV1), and low back pain during forced expiration. Twenty-two subjects (14 subjects in experimental group, 8 subjects in control group) participated in this study. The stabilizer was used for ADIM training for five consecutive days. Vitalograph PEF/FEV1 DIARY and visual analogue scale (VAS) were used to determine forced expiratory pulmonary function and low back pain, respectively. Independent t-test and analysis of covariance were used for statistical analysis with a significance level of .05. The findings of this study were as follows: 1) There were no significant differences of ADIM effect on PEF and FEV1 between experimental group and control group. 2) There was a significant pain reduction in experimental group with ADIM. 3) PEF and FEV1 increased significantly in the fifth day compared with the first day pre-exercise baseline. Therefore, it is concluded that ADIM was effective in improving PEF and FEV1, and reducing VAS during forced expiration in patients with chronic low back pain.

The purpose of this study was to assess the fatigue in lumbar and abdominal muscles in patients with chronic low back pain compared with normal subjects using spectral analysis with mean power frequency and median power frequency. The experimental group consisted of twenty subjects who had experienced chronic low back pain for over one year after the onset day. A control group consisted of twenty normal subjects with no history of low back pain. All subjects stood in an apparatus to perform sustained contraction in the lumbar and abdominal muscles for 30 seconds with 60% maximal voluntary isometric contraction (MVIC). The resulting electromyographic (EMG) recorded time serial data were transformed into frequency serial data by Fast Fourier Transformation (FFT). The results were as follows: 1) lumbar muscles measured, the frequency change ratio of both median power frequency and mean power frequency was significantly greater for experimental group compared with control group group (p<0.05). In measured two abdominal muscles (inferior rectus abdominis, obliquus externus abdominis) except superior rectus abdominis, the frequency change ratio of both median power frequency and mean power frequency was significantly greater for experimental group compared with control group (p<0.05). 2) In all three (longissimus thoracis, iliocostalis lumborum, multifidus) lumbar muscles measured, the initial frequency value of both median power frequency and mean power frequency was significantly lower for the experimental group compared with the control group (p<0.05). In the two (inferior rectus abdominis, obliquus externus abdominis) abdominal muscles measured (superior rectus abdominis not included), the initial frequency value of both median power frequency and mean power frequency was significantly lower for the experimental group compared with the control group (p<0.05). These results suggest that in patients with chronic low back pain there is a trend for more fatigue to occur in both lumbar and abdominal muscles than in the normal control group. This would seem to suggest that in treatment programs for patients with chronic low back pain, improvement of endurance in all trunk muscles should be considered.