Trial design. This double-blind randomized controlled trial (evaluators. patients) was planned with a pre-posttest aged 40-60, suffering from CNSLBP. Upon referring to the healthcare centers, the patients with CNSLBP are invited to participate in the study if they receive the approval of a neurosurgeon and meet the inclusion criteria. In this clinical trial, patients were randomly assigned to two experimental groups (CKCE N=20 and OKCEN=20) and control groups (n=20). The experimental groups followed CKCE and OKCE for 8 weeks and the control group did not receive any intervention. (13,14). The objectives and procedures were explained to the participants, and written informed consent was obtained by the Declaration of Helsinki. Ethical approval of the present study was obtained from the ethics committee for human research of BuAliSina University (reference number: IR.BASU.REC.1402.011, 22/04/2023) and IRCT CODE (20190129042534N1, 04/07/2023 ). Informed consent was obtained from all subjects and/or their legal guardian(s) - both for study participation and for publication of identifying information/images in an online open-access publication (when applicable).
Participants. The statistical population of this clinical trial was men with CNSLBP that suffering from CNSLBP. A total of 60 men were screened by nerve sub-specialists (With 20 years of experience) and voluntarily participated in this study (Figure 1). The inclusion criteria were as follows: history of pain for more than 12 weeks, age range between 40 to 60 years, no history of spine surgery, and hip joint replacement. The Exclusion criteria include pain in other segments, lower and upper limb deformity, consumption of painkillers in the past 6 months, physiotherapy in the past year, participation in sports, sciatica pain, spondylolysis, neuromuscular, neurological disorders, respiratory, muscle spasm, and fraction vertebrae. Patients signed an informed consent form before data collection(16).
Sample size and Randomization and blinding. We used G*Power software to determine the sample size. According to 5to the previous study, the power was 0.8, alpha 0.5, and the effect size was 0.8. The software output reported 60 subjects for this clinical trial (17). Random Allocation Software version 1.0 was used for randomization. Random codes were generated in blocks 4 and 6. We used sequentially numbered sealed envelopes to conceal allocation(18). A researcher who was not involved in data collection opened the sealed envelopes with consecutive numbers and delivered them to the patients(19). As a result, patients were randomly assigned to two experimental groups (CKCE N=20 and OKCEN=20) and control (n=20) groups. Of note, patients were not aware of group allocation. In addition, to maintain blinding, patients were instructed not to disclose information about the group allocation to the evaluators(20).
Intervention. After the evaluation of the mentioned variables, CKCE in water was performed in eight weeks, three sessions a week and each session was about 60 minutes under the supervision of the researcher for all three training groups in the same way. This part included about 5 minutes of general warm-up, about 50 minutes of motor chain exercises, and 5 minutes of cooling exercises in the form of stretching exercises. The primary goal of these exercises is to enable the patient to achieve control and coordination of the spine and pelvis using the principles of motor learning. The group of OKCE(in the deep part using noodles and under the care of four lifeguards) in the water for eight weeks, 3 sessions a week for 60 minutes in a group in the swimming pool of Buali Sina University, Hamedan, by a specialist in therapeutic exercises in water. became By previous studies(28,29,30,31,32), the training program for these groups increased in volume, intensity, duration, and repetition as an increase in the phasing of weeks (Table 1).
Table 1. Exercise program CKCE and OKCE
Outcome measures. Pain was assessed with a 10 cm visual analog scale. The VAS scale shows the pain sensation in people. The patient was asked to indicate the pain intensity during daily activities. Two numbers zero and ten are located at its two ends, the number zero means body pain and ten is considered the most severe possible pain. The samples are asked to place their pain level by placing their hand in the numbers between these ranges. The reliability of this test is reported as 0.97. In the present study, people with a pain score higher than 4 were included in the study(21,22).
LumboPelvic Stability. The Biofeedback Pressure device((Stabilizer®, Chattanooga Group, Inc., Hixson, TN, USA) was used to evaluate lumbar-pelvic control and was evaluated by four tests. The reliability coefficient of lumbar-pelvic control tests (0.86-0.90) has been reported (23). Moreover, a simple long-arm goniometer (Goniometer set, Gamatpoyan, Iran) with a 360 angle was used to control the starting positions of the hips and knees during KLAT and BKFO. To determine the LPC status of the participants in the groups with proper and poor LPC, the pressure changed from the baseline pressure (40 mmHg for supine tests or 70 mmHg for prone test), and the values of each test were recorded by the researcher. If the mean pressure change of all the tests was >|± 8| mmHg, the poor LPC group would be considered. If the mean pressure change of all the tests was ≤|± 8| mmHg, proper LPC would be considered (24).
1- Knee lift abdominal( KLAT) Test: The subject lies on his back, knees bent, and feet on the floor. The pressurized biofeedback bag was placed horizontally under the lumbar spine and the lower edge of the bag was placed at the level of the posterior superior sacral spine. The basic biofeedback pressure of this test was set to 40 mm Hg, then the subject was asked to lift one leg off the mat so that the hip and knee joint reach 90 degrees of flexion and keep it in this position for 4-6 seconds. (figure 1).
2- Bent kneefall-out(BKFO) Test: The subject was lying on his back, the bag of the device was vertically under the lumbar spine and the lower edge of the bag was 2 cm from the caudal part of the upper posterior cruciate ligament on the side of the leg where the test was performed. The subject is asked to flex the knee on the side where the bag was located by 120 degrees slowly move the hip to approximately 45 degrees of abduction and lateral rotation and return to the starting position. The other knee was in a neutral position and the foot was placed horizontally on the ground (Figure 2).
3- Active Straight Leg Raising(ASLR) Test: The subject was lying on his back and the pressurized biofeedback device bag was placed horizontally under the lumbar spine and the lower edge of the device bag was placed at the level of the posterior upper lumbar spine. The base pressure of biofeedback was set to 40 mm Hg. Then the subject was asked to raise one leg straight up to 20 cm and hold it for 20 seconds. The maximum pressure change read from the device needle is recorded as uncontrolled lumbopelvic movements(Figure 3).
4- Prone Test: The subject is lying on his back and the high-pressure biofeedback bag is placed between the upper anterior sacral spine and the navel. Before the start of each contraction, the bag was adjusted to 70 mmHg and then the subject was asked to breathe through his abdominal wall. After two normal breaths and adjusting the airbag again to 70 mm Hg, the subject was asked to perform three contractions with verbal feedback. This contraction was done in such a way that without moving the spine of the back and pelvis, the stomach was pulled in and the navel was close to the spine and maintained in the same position for 10 seconds(Figure 4)(25,26,27).
Statistical Analysis. Statistical analysis was performed using SPSS version 26 software. The Shapiro-Wilk test was used to ensure the data's normal distribution (P > 0.05). A covariance test was used to compare results between groups. The effect size was classified using Cohen's index (small: 0.01, medium: 0.06, large 0.14) (33).