Participants
This double-blinded study will be fulfilled using a statistical population of men, aged 40-60, suffering from CNSLBP. Upon referring to Omid Specialized Clinic, Hamedan, Iran, the patients with CNSLBP will be invited to participate in the study if they receive the approval of a neurosurgeon, Dr. Mahdi Arjipour, and meet the inclusion criteria. For the patients included, comprehensive explanations will be then given about the research methods and objectives This trial was approved by the ethics committee for human research of BuAliSina University (reference number: IR.BASU.REC.1402.011) and IRCT CODE (20190129042534N1) with the Helsinki Declaration. Written and informed consent will be obtained from all participants before the evaluation and intervention] 31[.
Inclusion and Exclusion Criteria
The inclusion criteria are male patients suffering from CNSLBP with at least three months of pain, the age range of 40-60, and the normal BMI ]32[. The patients are also randomized based on the Random Number Generator, and then placed into one of the following three groups with reference to the sequentially numbered, opaque, sealed envelope (SNOSE) technique and the block randomization method, viz., open kinetic chain (OKC) exercises (n=20), closed kinetic chain (CKC) exercises (n=20), and controls (n=20). Absence from two consecutive or three non-consecutive exercise sessions and unwillingness to participate in further sessions, the history of injury in the past year in the trunk and the lower limbs, surgery on the back and the lower limbs, inflammation in the spine, spinal fracture, tumors in the back, LBP of non-mechanical origin, or a neurological, cardiovascular, or psychiatric disease (e.g., major psychotic disorder and depression) are also considered as the exclusion criteria ]33[.This trial was approved by the ethics committee for human research of BuAliSina University (reference number: IR.BASU.REC.1402.011) and IRCT CODE (20190129042534N1).
Sample Size
In the present study, the G*Power software, the test power of 0.80, the effect size of 0.35, and the significance level of 0.05 will be used to estimate the sample size based on the repeated measures analysis of variance (ANOVA), so the output of 52 patients will be the sample size. In addition, eight more people will be added for the same purpose, considering sample attrition, and the final sample size will be 60 patients]33[.
Trial Setting and Intervention
The laboratory-based procedures will be performed at three steps. At the first step, the demographic characteristics of the patients, including height, weight, and BMI, will be evaluated with an electronic scale (Sahand BS100, Iran). As the second step, the psychological factors, such as perceived pain intensity and Kinsophobia will be evaluated. At the third step, the electrical activity of selected lumbar muscles, LPC, and GRF for balance analysis will be assessed at two stages, namely, before the exercises and within an eight-week interval.
Outcomes and Assessment
Primary Outcomes
The electrical activity of the selected lumbar muscles will be measured using an eight-channel electromyography (EMG) device (ME6000 Model, Mega-Vin, Finland) with a sampling rate of 1000 Hz. According to the SENIAM project (viz., the surface EMG for the non-invasive assessment of muscles), the passive silver-silver chloride electrodes are placed on the lumbar multifidus (MF) muscle after modification and cleaning with rubbing alcohol at the level of the L5 spinous process (that is, about 2-3 cm from the midline), the transversus abdominis (TrA) muscle (2 cm lower and inside the anterior superior iliac spine [ASIS]), the quadratus lumborum (QL) muscle (four oblique angles in the middle of the distance between the 12th rib and the iliac crest), the gluteus medius (GM) muscle (in the middle of the distance between the greater trochanter of the thigh and the outermost face of the iliac crest after removing excess hair and cleaning it by rubbing alcohol) ]34, 35[. To normalize the range of muscle work, the root-mean-square (RMS) of the muscle activity will be divided by the peak value of the submaximal voluntary isometric contraction of that muscle ]36[.
As the submaximal isometric contraction for the MF muscle is the Superman movement ]37[, the patient lies on the table in a palmar position after placing the electrodes on the given muscle, and performs the movements according to Figure 1. This test lasts 10 seconds, wherein three submaximal isometric contractions are repeated with 1-min rest intervals between each contraction.
Figure 1. submaximal isometric contraction for theMF muscle
Given that the submaximal isometric contraction for the QL muscle is a lateral bending movement along with the examiner’s resistance ]38[, the patient lies down on his side after installing the electrodes and the examiner performs the movement according to Figure 2 with the resistance of the steering wheel. The duration of this test is 10 seconds, in which three submaximal isometric contractions are repeated with 1-min rest intervals between each load contraction for the right and left sides.
Figure 2. submaximal isometric contraction for the QL muscle
Considering that the submaximal isometric contraction for the GM muscle is the thigh abduction movement along with the examiner’s resistance ]39[, the patient lies on the table in a palmar position upon placing the electrodes on the MF muscle, and moves one’s leg to the side without bending the knee (viz., abduction) with the examiner’s resistance, according to Figure 3. This test lasts 10 seconds, wherein three submaximal isometric contractions with 1-min rest intervals between each contraction are repeated for the right and left sides.
Figure 3. submaximal isometric contraction for the GM muscle
With regard to the submaximal isometric contraction for the TrA muscle, the patient is placed in a standing position after installing the electrodes, and moves the abdominal brace according to Figure 4 ]40[. The duration of this test is 10 seconds, in which three submaximal isometric contractions with 1-min rest intervals between each contraction are repeated for the right and left sides. Of note, sub-abdominal breathing will be done for the TrA muscle.
Figure 4. submaximal isometric contraction for the TrA muscle
After recording three electrical activities of the submaximal isometric muscle contractions and 5 min of rest, the activity of all mentioned muscles in the lateral plank movement with thigh abduction position on the left and right sides will be evaluated for 15 seconds (Figure 5) ]41[.
Figure 5. submaximal isometric contraction lateral plank
LPC
The pressure biofeedback (BFB) device is used to evaluate LPC. In this vein, there are four tests, whose reliability coefficient has been reported as 0.86-0.90 ]42[.
- Knee lift abdominal test (KLAT): The patient lies on his back, with the knees bent and the feet on the floor. The pressure BFB bag is then placed horizontally under the lumbar spine and the lower edge of the bag is positioned at the level of the posterior superior sacral spine. The base pressure is set to 40 mm Hg, then the patient is asked to lift one leg off the mat, so that the hip and knee joint reach 90o flexion, and keep it in this position for 4-6 seconds, as illustrated in Figure 6 ]43[.
figure 6. Knee lift abdominal( KLAT)Tes
- Bent knee fall-out (BKFO) test: The patient is lying on his back, the device bag is vertically under the lumbar spine, and the lower edge of the bag is 2 cm from the caudal part of the upper posterior cruciate ligament on the leg side wherein the test will be performed. The patient is asked to flex the knee on the side where the bag is located by 120o, slowly move the hip to approximately 45o abduction and lateral rotation, and return to the starting position. The other knee is also placed in a neutral position and the foot is put horizontally on the ground (Figure 7) ]44[.
figure 7. Bent kneefall-out(BKFO) Test
- Active straight leg raise (ASLR) test: The patient lies on his back and the pressure BFB device bag is placed horizontally under the lumbar spine and the lower edge of the device bag is at the level of the posterior superior iliac spine (PSIS). The base pressure is set to 40 mm Hg. Then, the patient is 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, as shown in Figure 8 ]45[
figure 8. Active Sraight Leg Raising(ASLR)
- Prone instability test (PIT): The patient is lying on his back and the high-pressure BFB bag is placed between the upper anterior sacral spine and the navel. Before the start of each contraction, the bag is adjusted to 70 mmHg, and then the patient is asked to breathe through his abdominal wall. After two normal breaths and adjusting the airbag again to 70 mm Hg, the patient is asked to perform three contractions with verbal feedback. This contraction is done in such a way that the stomach is pulled in, and the navel is close to the spine and maintained in the same position for 10 seconds without moving the back and the pelvis (Figure 9) [46[.
figure 9. Prone Test
Pain Intensity
The visual analogue scale (VAS) will be utilized to quantify pain intensity in the patients. It shows the sensation of pain, using two numbers, 0 and 10, at its two ends, wherein 0 means no pain and 10 represents the worst possible pain. The patients are thus asked to rate their pain by placing their hand on the numbers. The reliability of this test has been reported as 0.97 ]47[. In the present study, the patients with a pain score higher than 4 are included ]48[.
Secondary Outcomes
GRF:The vertical GRF is measured using a plantar pressure measurement device (FDM-S Model, Zebris, Germany), while walking. To evaluate the variables, the patients will walk a 10-m path, and there is a foot pressure plate with the dimensions of 54×34 cm as well as 2560 sensors with high sensitivity (one sensor per cm2) in the middle of the way to record the pressure in the range of 1-120 N/cm2. It will be embedded in the track floor, and the patients will be blinded to it. In general, the signals will be recorded when the foot completely touches the middle part of the device. For this purpose, the foot pressure variables will be analyzed using the Win FDM-S software (ver. 01-02-09) ]49[.
Fear of Movement or Re-Injury (or Kinesiophobia)
Kinesiophobia has been proposed as a characteristic factor in patients with musculoskeletal pain. The Tampa Scale of Kinesiophobia (TSK) was thus created by Corey et al. (1991) to measure the fear of pain/re-injury in patients with chronic pain ]50[. To assess the degree of disability caused by CNSLBP, the TSK can be thus administered. To eliminate bias, the researcher will repeat the questionnaire items in simple language to the patients, and they will be asked to show their level of agreement with each one (n=11) on a scale of (1) completely disagree, (2) somewhat disagree, (3) somewhat agree, and (4) completely agree. As a result, higher scores indicate an increase in the fear of re-injury due to movements. The psychometric properties of this scale had been already investigated in an Iranian sample suffering from LBP, with the Cronbach’s alpha coefficient equal to 0.79 and the test-retest reliability coefficient of 0.86 ]51[.
Intervention Program
O/CKC Exercises in Water
Once the mentioned variables are evaluated, the O/CKC exercises in water are practiced during eight weeks, three sessions a week, and each session will be about 60 min, with the supervision of the researcher for all exercise groups in the same way. This will include about 5 min of general warm-up, 50 min of O/CKC exercises, and 5 min of cooling exercises in the form of stretching movements. The primary objective of these exercises is to enable the patients to achieve the control and coordination of the spine and the pelvis based on the motor learning principles. The group with OKC exercises (in the deep part using noodles and under the care of four lifeguards) practices the movements in water for eight weeks, three sessions per week, for 60 min, in the swimming pool of Bu-Ali Sina University, Hamedan, Iran, under the supervision of a hydrotherapist ]52[. The exercise program will be augmented in volume, intensity, duration, and repetition in accordance with previous studies in the form of the increased phasing of weeks(Table 1) ]51[.
Table 1. O/CKC Exercises in Water
Time
|
Closed Chain Exercise group
|
Open Chain Exercise group
|
Warm up
Minutes(5)
|
- Walking back and forth with increasing speed in the shallow part of the pool
- Stretching exercises for the large muscles of the body (especially the hamstrings, periformis, and quadratus lumborum).
|
- Walking back and forth with increasing speed in the shallow part of the pool
- Stretching exercises for the large muscles of the body (especially the hamstrings, periformis, and quadratus lumborum).
|
The main exercise
(40) minutes
Every exercise
Minutes (4)
|
- Breathing exercises
- Exercises to activate transverse abdominal muscles and multifidus
- Walking forward with straight knees (parade walk)
- Walking backwards with long steps
- Lateral walking with long steps
- Walking with trunk rotation
- Walking with consecutive stops on one leg
- Flexion and extension of thigh in single leg position with straight knee
- Shoulder flexion and extension in half squat position (12 x 3 repetitions)
- Shoulder abduction and horizontal adduction in the half squat position (12 x 3 repetitions)
- Performing thigh and knee extension simultaneously with ankle plantar flexion and then thigh and knee flexion simultaneously with dorsiflexion (12 x 3 repetitions)
|
- Breathing exercises using noodles in the deep part
- Exercises to activate transverse abdominal muscles and multifidus using noodles in the deep part
- Bending and opening the thighs with straight knees (parade walking) using noodles in the deep part
- Pedaling (similar to riding a bicycle) backwards using noodles in the deep part
- Bringing the legs closer and closer with a straight knee using noodles in the deep part
- Bringing the elbows to the knee of the opposite leg while rotating the trunk using noodles in the deep part
- One leg bicycle leg using noodles in the deep part
- Thigh flexion and extension in the floating position using noodles in the deep part
- Flexion and extension of the shoulders in half squat position (12 x 3 repetitions) using noodles in the deep part.
- Shoulder abduction and horizontal adduction in half squat position (12 x 3 repetitions) using two noodles in the deep part
- Performing thigh and knee extension simultaneously with ankle plantar flexion and then thigh and knee flexion simultaneously with dorsiflexion (12 x 3 repetitions) using noodles in the deep part
|
Cool down
Minutes(5)
|
- Walking at a reduced speed in the shallow part of the pool
- Stretching exercises for upper and lower body muscles
|
- Walking at a reduced speed in the shallow part of the pool
- Stretching exercises for upper and lower body muscles
|
Statistical Methods
After the completion of the intervention program, the post-test stage will be conducted similar to the pre-test one, and the raw data will be analyzed using the IBM SPSS Statistics software package (ver. 26). To confirm the normality of data distribution, homogeneity of variance, linearity, and homogeneity of regression slope, Shapiro-Wilk test, Levene’s test, scatterplots, and interactions between independent variables will be used, respectively. Repeated measures analysis of variance (ANOVA) will be further utilized for statistical analysis and Bonferroni’s post hoc test will be operated for pairwise comparisons between the study groups. The type I error of 0.05 will also be taken into account.