Injured workers benefit from chiropractic adjustments

J Manipulative Physiol Ther. 2009 (Nov); 32 (9): 765–771

Donald Aspegren, DC, MS, Brian A. Enebo, DC, PhD, Matt Miller, MD, Linda White, MD, Venu Akuthota, MD, Thomas E. Hyde, DC, James M. Cox, DC

Department of Rehabilitation, University of Colorado School of Medicine, Lakewood, CO 80215, USA. dr.dda@comcast.net

OBJECTIVE: The purpose of this study is to report on integrative care for the treatment of injured workers with neck or back pain referred to a doctor of chiropractic from a medical or osteopathic provider.

METHODS: This retrospective case series study evaluated data on 100 patients referred for chiropractic care of work-related spinal injuries involving workers’ compensation claims. Deidentified data included age, sex, visual analog scale scores for pain, pre- and posttreatment Functional Rating Index (FRI) scores, and subjective response to chiropractic care. Based on date of injury to first chiropractic treatment, patients were subdivided as acute, subacute, or chronic injured workers. Cases were analyzed for differences in pretreatment FRI scores, posttreatment FRI scores, FRI change scores (posttreatment FRI minus pretreatment FRI score), and subjective percentage improvement using a 1-way analysis of variance. Treatment included manual therapy techniques and exercise.

RESULTS: Injured workers with either an acute or subacute injury had significantly lower posttreatment FRI scores compared with individuals with a chronic injury. The FRI change scores were significantly greater in the acute group compared with either the subacute or chronic injured workers. Workers in all categories showed improved posttreatment tolerance for work-related activities and significantly lower posttreatment subjective pain scores.

CONCLUSIONS: The study identified positive effects of chiropractic management included in integrative care when treating work-related neck or back pain. Improvement in both functional scores and subjective response was noted in all 3 time-based phases of patient status (acute, subacute, and chronic).

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Discussion

The time lapse between injury onset and date of first chiropractic treatment may influence functional treatment outcomes. More specifically, workers with acute and subacute injuries had greater improvements in posttreatment FRI scores than did injured workers with a chronic injury. In addition, when the change in FRI was considered, acutely injured workers had a larger relative difference between pre- and posttreatment FRI scores. Consistent with functional improvements, there appeared to be greater posttreatment tolerance for work activity in the acutely injured workers.

Return to Work

There is an inverse relation between absenteeism after an injury and the likelihood of return to the workplace. [5, 15] Pransky et al [16] describe the importance of regaining work status, noting that prolonged disability may result in workers losing confidence in their ability to perform work-related duties with consequential compromise in their return to work. In our study, improvement in work status was noted in acute, subacute, and chronic groups (Figs 2-4).

Natural History

It may be suggested that our results represent natural history findings. Early natural history reports of acute low back pain suggested spontaneous resolution within 4 to 6 weeks in 80% to 90% of cases. [17-19] However, this has been recently challenged by several reports. Hestbaek et al, [20, 21] Carey et al, [22] and later Nachemson and Jonsson [19] describe how acute low back pain becomes chronic or recurrent more frequently than previously suspected. Jayson [23] expanded on these concerns, noting at 3 months that the natural history prognosis for patients having experienced an acute episode of low back pain was as follows: 27% were completely better, 28% improved, 30% had no change, and 14% were actually worse. Theories of why patients may continue with pain beyond the 6-week period or experience a relapse are plentiful. Hides et al [24] describe observations of stabilizing muscles, such as the lumbar multifidus, not demonstrating spontaneous recovery of function after the remission of acute low back pain symptoms. Basic science studies by Hodges et al [25] recently observed enlargement of adipocytes and clustering of myofibers at multiple spinal levels 3 to 6 days after disk and nerve lesions. Their study suggested that these changes may be due to rapid disuse associated with reflex inhibitory mechanisms. [25] Studies such as these raise a clinical concern of an extended delay period before initiating care because these observed changes may manifest in patients with spinal injures, resulting in higher relapse rates and the potential development of chronic status. Our results demonstrated improved response in functional activity gains, subjective improvement reports, and self-perceived work status in all 3 time frame groups of patients; but these results were heightened if chiropractic care was initiated closer to the time of injury.

In our study, disability and actual work status were controlled by the referring physician. Several reports [26-29] in the literature describe how the frequency of disability application may be reduced by improving injured worker satisfaction scores. Workers having negative postinjury experiences with employers, health care providers, and case managers are more likely to apply for disability as a result of their injury. [28, 29] Because of escalating disability rates in the United States, several authors suggest improving postinjury worker satisfaction to decrease the incidence of the injured worker eventually applying for disability. [28, 29] This dissatisfaction is believed to be one reason why injured workers seek attorney involvement, thus delaying case closure and increasing disability. [30, 31] We did not evaluate satisfaction levels in our patients; however, it is noted that chiropractic providers have historically scored high in patient satisfaction assessment [6, 9, 32, 33] and, as a result, may prove useful to decrease the number of eventual disability applicants.

Our patients received a pathology-based diagnosis. We attempted to stay consistent with much of health care that is departing from the pathoanatomical model of treatment and embrace a more progressive biopsychosocial model with appreciation of cognitive factors. [19,34-36] Emphasis was placed on return to work with consequential reduction of stress and anxiety; and as Anderson et al [37] documented, this may improve treatment outcomes. Recovery was further promoted by instructing the injured worker to focus on increasing exercise or physical activity outside of work, while decreasing deconditioning-type activity such as excessive bed rest.

Manipulation in Treatment

Regarding the use of manual techniques, 2 types of SMT were commonly performed on the injured workers in our study. The first was HVLA manipulation, the most commonly referenced form of manipulation in the literature. [38] The second was FD, a form of manipulation that is commonly known within the chiropractic profession for its positive effects on disk pathologies [11,39-41] but also has been shown to have positive clinical results on articular structures of the spine and surrounding pain-generating paraspinal tissues. [12, 41, 42] These are the 2 most commonly used forms of manipulation used by the chiropractic community. [43] The goal of using HVLA and/or FD manipulation was to reestablish normal preinjury distribution of mechanical loads through the targeted spinal articular structures identified in each case and ameliorate irritation to associated involved joints. By attempting to reestablish normal motion, healing is promoted in nociceptive pain generators through a dissipation of pathologic stress and a return to normal activity. Gudavalli describes in Cox’s text [41] how FD manipulation has been shown in cadaveric study to decrease intradiskal pressures, increase intervertebral disk space height, increase foraminal area, and help restore facet joint physiologic ranges of motion. Additional positive effects of manipulation were recently described by Bolton and Budgell, [44] finding that these effects may go beyond the effects of disrupting intraarticular adhesions or releasing entrapped synovial folds. In their report, it is theorized that manipulation may have a particular effect on stimulating mechanoreceptors within deep intervertebral muscles, whereas mobilization techniques were more likely to affect superficial axial muscles.

Adverse Response

Spinal manipulative treatment will cause posttherapeutic soreness in some cases. [45-49] In our study, 10.2% of 68 cases that did not finish care was believed to be due to soreness possibly experienced from treatment. Senstad et al [47] reported that 90% of all reactions were graded by patients as moderate or slight and commenced on the day of therapy in 87% of cases, and disappeared within 24 hours in 83% of cases. No reactions were classified as severe or serious. [47] Most common reactions included local discomfort (55%), headache (12%), tiredness (11%), and radiating discomfort (10%). There were no reports of serious complications in this study. [46] Hurwitz et al [48, 49] evaluated the adverse effects of post-SMT on patient satisfaction scores and perception of improvement. Twenty-five percent [49] to 30% [48] of respondents reported at least 1 adverse reaction. In our study, the benefits of SMT and concerns of post-SMT reactions were discussed with patients before treatment. Other than soreness, no serious complications were reported in our study.

Physical Modalities

In addition to manipulation and exercises, all of our patients received one or several physical modalities including instrument-assistive soft-tissue technique (ie, Graston technique), electrotherapy, or hot packs. Haas et a [l7] describe their clinical study finding dose-dependent linear positive clinical effect for patients receiving physical modalities and manipulation. Patients receiving manipulation alone did show signs of improvement, but not at the same rate.

Work Restrictions

Work restrictions and limitations as well as days of disability were controlled by the medical or osteopathic provider. Questions regarding this area were deflected back to the referring provider. The benefit of this integrative care was that the treatment team was more consistent when one voice communicated to the patient, rather than allowing confusion to occur. Timing for return to work and/or limitations of work are an important area of care and must be handled properly by returning the worker to employment as soon as safely possible. All parties involved benefit by the workers’ rapid safe return to work.

Functional Status and Pain Scores

We used an FRI50 to evaluate status of the injured worker before chiropractic treatment began and at the end of chiropractic care. The FRI is a self-reporting instrument consisting of 10 items, each with 5 possible responses that express graduating levels of disability. Items evaluated included pain intensity, sleeping, personal care, travel, work, recreation, frequency of pain, lifting, walking, and standing. Regarding clinical utility of the FRI, the average time required to complete was 78 seconds. The tool was easy to understand and self-administered. Stewart et al [51] recently identified the FRI as a common disability index used today. Tests for reliability and validity were performed and supported in the original Feise and Menke [50] article.

Pain scores were recorded on all patients upon entry into chiropractic care. McGeary et al [1] report that findings from their multidisciplinary occupational rehabilitation program that elevated pain ratings before rehabilitation were associated with increased dropout rates, higher self-reported depression, and disability after rehabilitation. In our study, patients absent of Waddell et al [52] nonorganic signs for their back injury and absent of Sobel et al [53] cervical nonorganic signs would be classified into one of several phases of rehabilitation, as described by Triano et al. [54] Patients with elevated pain levels were commonly placed in entry-level rehabilitation resulting in more of a basic exercise approach and more basic manipulative procedures with greater emphasis on passive modalities.

Limitations

A limitation of our study was the lack of a separate control group. Hunter et al [55] describe similar limitations in their worker’s compensation study incorporating functional restoration procedures where concerns are raised on limiting care by creating a control group. Further limitations are noted with study weakness involving a retrospective case series. Findings in this study may not necessarily be applicable to other patient populations and locations. The study set the foundation of a future prospective study.

Conclusion

The study demonstrated positive effects of including chiropractic services in integrative care when treating compensable neck and/or back pain. Patients recorded improvement in functional scores and subjective response involving work-related spinal injuries. Improvement was noted in all 3 time-based phases of patient status (acute, subacute, and chronic).