In our highly industrialized world, low back pain (LBP) has become a major health issue because of its high prevalence in the general population and adverse effects on health. Low back pain is a general term characterized by acute ( < 6 weeks), subacute (6-12 weeks), or chronic (>12 weeks) pain, all of which are duration dependent and location specific. In the health care profession, LBP is known by various names and treatment differs accordingly. General practitioners may use lumbago; physiotherapists may call it hyperextension, a manual therapist may call it facet joint disorder, and orthopedic surgeons may call it a degenerative disc problem. However, at present no reliable and valid classification system exists for diagnosis and prognosis of LBP (15). Several researchers suggested different predictors (walking distance, disability, physical functions, quality of life, stress, stand ups, stair climbing, depression, work losses, cognitive factors, sitting, pain, etc.) for LBP; among these, pain was considered to be the most indicative variable (15).
Low back pain is not necessarily a consequence of degenerative processes; many patients with recurring LBP have no evidence of degenerative changes, and many people who do have degenerative radiological changes have no back pain. Numerous hypotheses concern the cause of nonspecific LBP, including reduced trunk extensor endurance (18), psychological distress (5), hamstring flexibility (12), poor muscle control of the trunk (11), poor posture (23), and low body mass (23).
LBP is a multifactorial disorder with many possible causes. Treatment for LBP varies considerably. It includes medication, physical therapy modalities, and exercise therapy (31), and each have several interventions. Practice guidelines recommend various types of exercises and manipulative therapy for chronic LBP, but there have been few head-to-head comparisons of these interventions (20). In recent years, multidisciplinary pain programs were seen to successfully treat patients by basing treatment on a combination of physical exercise and psychological interventions (28). However, despite their effectiveness, it still remains to be clarified exactly which features of these programs were responsible for patient improvement (28). Interventions such as the application of heat, short-wave diathermy (SWD), and massage alone have insufficient evidence to support their effectiveness at present, but they were found to be effective and more cost effective than no intervention.
Athletes, especially hockey players, are more prone to LBP as a result of their regular forward bending play, which leads to derangement syndromes. This derangement not only destructs their skills and ability to play, but also produces stress and, in the long run, disability. Therapeutic exercise, as part of rehabilitation for patients with LBP, is one of the treatment modalities most commonly used by physiotherapists (21). In the management of such cases, the dynamic muscular stabilization techniques (DMST) were found to be effective (17). Through DMST adequate dynamic control of lumbar spine forces is achieved, thus reducing the repetitive injury to the structures of the spinal segments and related structures. Specific stabilizing exercises with co-contraction of deep abdominal (transversus abdominis) and lumbar multifidus muscles enhance the spinal segmental support and control (30). In recent clinical trials, these exercises have proved effective in the management of LBP both in the short and long term (10).
No randomized comparisons have been done of the effects of general exercises and spinal manipulative therapy specifically for the management of chronic LBP, so it was not clear which of the treatments is most effective (20). There is still no evidence as to which exercises or which training is best for different subgroups (19,27). In clinical reality, modalities and training are often used in combination to relieve pain and improve function. Patients often get better, but the pain recurs frequently and many patients undergo treatment again and again.
Keeping these facts in mind and to the best of our knowledge, for the first time the combination of 2 electrotherapy (ultrasound and SWD) and 1 exercise therapy (lumbar strengthening exercises [LSE]) was named “conventional” and compared with “DMST,” an active approach of stabilizing training. We hypothesized that DMST may be more effective than conventional in the management of subacute or chronic low back pain. To test this hypothesis, this study was designed and the effects of 2 independent variables (days and treatments) were assessed on 4 dependent variables: walking, stand ups, climbing, and pain.
Experimental Approach to the Problem
The subjects were randomly assigned equally into 2 groups by a lottery method. For this, 30 folded papers of the same shape and size were marked either “Conventional” or “DMST”; kept in a box; and mixed thoroughly before and after withdrawing a paper from the box by the player on a first-come, first-serve basis. The marking on the paper drawn by the player allocates his mode of treatment.
All tests were performed for dependent variables (walking, stand ups, climbing, and pain) by the same tester and same physiotherapist supervising the test procedure at baseline and on days 21 and 35. Test and retest were conducted in the same place at the same environment and at the same time of the day. The interval between tests and retest was 21 and 35 days from baseline. Subjects were told not to eat for 2 hours before each test. Before experimentation, all subjects were taught about the measurement variables and their outcomes. The players were also informed about the experimental risks, if any.
A total of 30 male hockey players from Sports Authority of India (SAI), Lucknow, aged 18 to 28 years who were diagnosed clinically by a physician with no neurological involvement but having symptomatic (overuse, overload, or overstretching) nonspecific subacute or chronic low back pain (CLBP), were included for this study. After randomization, players' physical and other characteristics were taken (Table 1). The baseline mean age, weight, height, and BMI (body mass index) of the 2 groups and other characteristics such as gender, type of pain, duration of sports training, and nutrition intake were found to be the same. The present study has the approval of the Institutional Review Board, and informed consent was obtained from the hockey coach, SAI, Lucknow, and from all the participants.
After group allocations, respective subjects were treated either with conventional or DMST. Both the treatments were given as individual treatment by the same physiotherapist with the same intensity and capacity on alternate day for 35 days. The duration of each individual treatment session was about 40 minutes per day. The subjects were not allowed to receive any other treatment, including pain killers. A brief description of both the treatments used follows:
Ultrasound, SWD, and lumber strengthening exercises.
For the purpose of this study as a treatment for a chronic condition, a frequency of 1 MHz was used rather than 3 MHz, which penetrates least and is absorbed superficially (7). Continuous pattern ultrasound is recommended for use in chronic conditions at intensity 1.2 W/cm2 for a period of 8 minutes for 18 sittings in 18 alternate days. Ultrasound equipment was used from Medichem Electronics, which has international standard certification.
SWD is a deep heating modality used in relieving pain. It is also used to enhance flexibility and blood flow and reduce inflammation. Short-wave forms are used for selected patients without neurological lesion (2). Continuous mode of SWD is used for 15 minutes with 18 sittings in 18 alternate days. The SWD was used from Medichem Electronics, which has international standard certification.
Lumbar Strengthening Exercises
The uses of LSE are well documented (16), including spinal extension exercises and trunk extensor muscles exercises. LSEs were done for 10 repetitions each exercise per sitting on alternate days.
Dynamic Muscular Stabilization Treatment
In DMST, muscles with direct attachment to the lumbar spinal segment stabilize the joints “neutral zone” and prevent excessive deflection (4). Exercise is given in 4 stages (Figure 1) in the following order:
(i) First week: Isolation and facilitation of target muscles. Verbal instruction such as drawing in and hollowing the lower abdomen, drawing the naval up and in toward the spine, or feeling the muscle tighten at the waist. From the beginning the patient learns to breathe normally while activating or holding the muscular contraction (24). The patient is in supine hook lying position and instructed to perform abdominal hollowing (in which the patient is instructed to make the lower abdomen cave in) or abdominal bracing (in which the patient is instructed to contract the abdominals by actively flaring out laterally in the region of the waist just above the iliac crest) (Figures 1A and 1B).
(ii) Second week: Training of trunk stabilization under static conditions of increased load. The patient's position and concentration pattern are the same as the first week; the individual is then asked to hold the position while load is added via the weight of the lower limbs being moved passively into a loaded position (Figures 1C and 1D).
(iii) Third week: Development of trunk stabilization during slow controlled movement of the lumbar spine. Once stability is trained through static procedure, the movement of the trunk will optimize the activation of the supporting muscle. The first step is to produce and explore lumbopelvic movement and learn abdominal hollowing or bracing in a variety of positions: sitting, quadruped, standing, supine, kneeling, and inclination by degree to control loading (Figures 1E and 1F).
(iv) Fourth and fifth weeks: Lumbar stabilization during high-speed and skilled movement. High-speed phasic exercises are recommended to the patient along with abdominal hollowing or bracing in a variety of positions.
Response (Dependent) Variables
The effects of treatments were assessed on 5 minutes of walking distance (m/5 minute), per-minute number of stand ups (number/min) and stair climbing (number/min), and level of pain (cm) on day 0 (before the treatment), day 21 (during the treatment), and day 35 (end of the treatment). The functional ability (walking, stand ups, and climbing) were measured according to the Waddle functional evaluation test (33), whereas level of pain was measured by the Visual Analogue Scale (VAS: 0-10 cm) (13). The measuring details of variables in brief are summarized as follows:
5 Minutes of Walking
The distance of a walk up and down between marks 10 m apart in 5 minutes. The corridor was quiet and empty with a nonslip surface or hard carpet. The patient could not use any walking aid but could use the walls for support or sit down for a rest. Regular information about the time was given to the patient between walking.
One-Minute Stand Ups
The number of times the patient can stand up from a chair in 1 minute is his score. The chair was firm and upright with a back rest but no arm rest. The seat height of the chair was 45 cm. During stand ups, there was no support within reach so the patient could not use any support.
Climbing up and down standard stairs with 1 handrail and an opposite wall within easy reach were used. Stair climbing counts of a patient were taken as total steps ups and downs completed in 1 minute (e.g., a patient can go up 10 steps and down 18 steps, so the total counts are 28).
Visual Analogue Scale
The VAS is a 10-cm calibrated line with 0 representing no pain and 10 representing the worst pain. The subjects were asked to make a mark or point on the scale that best represents his intensity of pain experienced. The distance between 0 and the mark or point was then recorded.
The effect of 2 independent factors (days and treatments) on each of 4 dependent variables (walking, stand ups, climbing, and pain) was assessed by 2-way analysis of variance (ANOVA) with repeated measures (within treatments) followed by Newman Keuls post hoc test. Before performing the ANOVA, the homogeneity of variance testing for each interaction (days × treatments) was done by Hartley, Cochran C, and Bartlett Chi-square methods. The relative association of each variable with time (days) and among variables for both the treatments was assessed separately by Pearson correlation coefficient (r), whereas functional dependence by regression analysis, considering time as independent variable and outcome of the variable over the period as dependent variable and their coefficients (α and β) were compared by t-test. The test-retest reliability of both the independent factors of each dependent variable was assessed by intraclass correlation coefficient (rI). A 2-tailed probability value less than 0.05 (p ≤ 0.05) was considered to be statistically significant. Microsoft Excel (MS Office 97-2003), GraphPad Prism (version 5), and STATISTICA (version 7) were used for the analysis.
For easy interpretation of the data, a percent change (from baseline to end of treatment) was calculated as follows:
The functional ability (walking, stand ups, and climbing) and level of pain of 2 treatment groups were summarized in Table 2, and responses of each individual over treatments were shown graphically in Figure 2. Table 1 shows that the average functional ability in both the treatments increases with time, whereas level of pain decreases. The increase in functional ability and decrease in pain seems to be higher in DMST than in the conventional treatment.
Table 3 showed that the variance of interaction (days × treatments) was homogeneous (p > 0.05). The analysis of variance revealed that both days and treatments have significant (p < 0.01) effects on walking, stand ups, climbing, and pain (Table 3). Their interactions (days × treatments) were also significant (p < 0.01), except climbing. The subjects' matching was effective (p < 0.01). In both the treatments, the mean levels of all variables between days (within subjects) differed significantly either at p < 0.05 or p < 0.01, except walking in conventional (day 0 and day 21) (Table 2). Similarly, the mean levels of all variables differed significantly (p < 0.01) between treatments (between subjects) except on day 0. The levels of all variables on both day 21 and day 35 were significantly high (p < 0.01) in DMST than in conventional, except pain, which was similar (p > 0.05) at day 21.
Table 4 shows that all functional ability of both the treatments has significant (p < 0.01) and positive correlation with the time (days), whereas pain has significant (p < 0.01) and negative correlation. The correlations of variables with time and among variables were comparatively higher in DMST than in conventional.
Comparing regression (Table 5) coefficients (α and β), the intercept (α) of all variables in 2 groups did not differ significantly (p > 0.05), whereas slopes (β) differed significantly (p < 0.01). The slopes of all variables were significantly (p < 0.01) higher in DMST than in the conventional.
The test-retest reliability of both the independent factors (days and treatments) for each dependent variable was assessed separately by intraclass correlation coefficient reliabilities (ICCRs). The dependent variable-walking, stand up, climbing, and pain-shows high reliability of 0.997, 0.995, 0.977, and 0.995, respectively, for days and 0.998, 0.995, 0.915, and 0.981, respectively, for treatments.
The response of the treatments on subject's functional ability (walking, stand ups, and climbing) and pain was assessed separately by subtracting successive-day response from previous-day response. The 0 or negative score was considered as nonresponse and positive score was considered as a favorable response. Table 6 showed that in both the treatments the proportions of responders are higher than the nonresponders and higher in DMST (99.2%) than in conventional (95.0%), and the responders were higher at day 21 than at day 35. In both the treatments, subjects' response over pain was the most (100.0%) and their response of climbing was the least (96.7%). No major adverse effects were recorded in any of the patients in either group.
In the present study both therapies (conventional and DMST) are found to be effective in the early recovery of patients with subacute or chronic low back pain, especially in pain control. The hypothesis that the treatment DMST is more effective than the conventional was found to be true. The DMST showed net improvement (% mean change from baseline to end of the treatment) of 7.0, 34.8, 34.6, and 79.2%, respectively, in walking, stand ups, climbing, and pain, whereas improvement in the conventional treatment group was 1.5, 17.7, 24.5, and 38.1%, respectively, which was 4.7, 2.0, 1.4, and 2.1 times higher, respectively, in DMST than the conventional. The correlation of walking, stand ups, climbing, and pain with time (days) suggests that all variables in DMST improved with time more significantly than the conventional; regression analysis (ratio of β coefficients) showed that it was 4.9, 2.5, 1.6, and 2.3 times higher, respectively, in DMST than the conventional. In both the treatments, the proportions of responders are higher than the nonresponders and higher in DMST (99.2%) than the conventional (95.0%). In the present study, variance of interactions (days × treatments) are homogeneous, subject matching was perfect, and test-retest reliability of both independent factors (days and treatments) of all dependent variables are significant. The mechanism by which these treatments improved LBP is not clear. We think that in conventional treatment, limited muscle groups were involved and not aimed at improving strength. In DMST the more improvement may be a result of restored muscle strength in combination with balance, posture, position, and coordination in the presence of pain and functional disability.
Previous comparative study among stabilizing training with manual treatment shows that the individual of stabilizing group more improved than the manual treatment group (6). A systematic review of the efficacy of McKenzie therapy also results in a greater decrease in pain and disability in the short term than other standard therapies (3). In a comparative study, the manipulative treatment with stabilizing exercises was found more effective in reducing pain intensity and disability than the physician consultation alone (26). In another study, pulsed SWD was compared with continuous SWD in LBP and pulse SWD was found to be more effective than continuous SWD (25). A study was done to compare cognitive intervention and exercise in patients with chronic LBP, and the effects of both the treatments were found to be similar (1). In a study that compares manipulative therapy with massage and SWD, the effect of manipulative therapy was slightly better than placebo therapy, no treatment, massage, and SWD (20). A comparative study on manipulation and stabilization exercises in patients with LBP suggests that patients with lumbar hypomobility experienced greater benefit from manipulation and those having hypermobility were more benefited by stabilization exercises (8). One study showed that patients with chronic low back pain demonstrated a reduction in performance of trunk extensor and flexor muscles when compared with a control group while using conventional trunk strengthening exercises. This study also suggests back extensor muscles deficiency should be considered in planning rehabilitation programs for patients with chronic low back pain and recommends that if passive modalities fail to restore function in 1 month, then active care or stabilizer muscle activation through stabilization exercises is needed (22).
All guidelines consistently report that acute LBP typically has an excellent prognosis because most cases (up to 90%) recover within 6 weeks (29,32). Musculoskeletal physiotherapy has seen an increase in the prescription of exercise to rehabilitate spinal stability in patients with chronic low back disorder (30). However, the prognosis for acute low back pain during play activity has been investigated and has been confidently reported as excellent in all current clinical practice guidelines for the management of acute low back pain (14).
Physiotherapy programs have shown efficacy in patients with chronic low back disorder (9). The spinal physiotherapy program was concerned with the physiotherapy of muscles and the progression of implementation contraction of these muscles into everyday postures and positions, especially those associated with pain or functional disability. As a component of musculoskeletal physiotherapy, the spinal stabilization program is more effective than manually applied therapy or an education booklet in treating low back disorder over time (17).
Correct and timely rehabilitation is a vital component of the treatment of sports injuries. The goals of rehabilitation include restoring function, restoring pain-free full range of motion, and achieving full muscle strength and sports endurance. Generally, sports rehabilitation entails a phased approach including progressive exercises and therapeutic modalities to achieve full recovery. This paper discusses the rehabilitation of LBP with the application of DMST and a special focus on the transverses abdominus and multifidi muscles, which is a necessary part of physical therapy for LBT. Literature review suggests that there is a need for this type of comparative study in cases of sports injury rehabilitation. Exercise programs may play an important part in muscle strengthening and prevention of future or recurrent injuries; there also may be important psychologic benefits. Lumbar stabilization exercises are aimed at sensorimotor reprogramming of spine stabilizer muscles intended to improve their motor control skill and delay of response and consequently to compensate for weakness of the passive stabilization system. Our results cannot be generalized to other populations because all subjects participating in this study were players. Therefore, the benefits of lumbar stabilization used in this study should be confirmed in other populations, which is our next aim.
Overuse injuries are common in sports, especially hockey, affecting predominantly the ankles and lower back. Physiotherapists, especially sports physiotherapists, were less concerned with a systematic approach (prospective) and the majority were taken from cases in which the rehabilitation intervention had been completed (retrospective) or used their experiences. This study concludes that for the management of low back pain, DMST is more suitable than conventional treatment. DMST not only enhanced the average capacity of walking, number of stand ups, and climbing, but also reduced pain more significantly. The rate of recovery was also found significantly higher in DMST than in conventional treatment. The findings can be helpful to care providers, therapists, and people with chronic back pain.
One of the senior authors is a PhD scholar and was a physiotherapist attached with SAI, Lucknow. The authors want to acknowledge all the participants in the trial. We also would like to acknowledge the director, SAI, Lucknow, and coaches, especially hockey coach Mr. Raja, for their necessary help and Mr. Madhusudan Tiwari, assistant physiotherapist, for helping in taking the measurements. In addition, we acknowledge ICMR New Delhi for providing a Senior Research fellowship (letter no. 3/1/2/1/ADR/2007-NCD-I). This study has no conflict of interests to report.
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Keywords:© 2009 National Strength and Conditioning Association
back pain; hockey; physiotherapy; stabilization; strengthening exercises