Assessment of Long-term Effects of Adding Osteopathic Manipulative Treatment to Neck Exercises for Individuals With Non-specific Chronic Neck Pain: A Randomized Trial

Abstract

Objective

The purpose of this study was to evaluate the long-term effects of adding osteopathic manipulative treatment (OMT) to neck exercises compared to exercises alone for individuals with non-specific chronic neck pain (NCNP).

Methods

A randomized controlled trial was conducted by assigning 90 individuals with NCNP into the following 2 groups: (1) exercises group (EG, n = 45) or (2) OMT plus exercises group (OMT/EG, n = 45). All participants received 4 weeks of treatment. The clinical outcomes were recorded at baseline and at 3 and 6 months after the treatment. The primary outcomes were pain and function—Numerical Pain Rating Scale (NPRS), Pressure Pain Threshold, and the Neck Disability Index (NDI). The secondary outcomes included range of motion for cervical spine rotation, Fear-Avoidance Beliefs Questionnaire, and Pain Self-Efficacy Questionnaire.

Results

In comparison to baseline data, both groups had a reduction of NPRS (P < .05) and NDI (P < .05) after the treatment. However, no statistically significant differences in pain intensity or disability were found when OMT/EG was compared to EG alone at 3 months (P = 0.1 and P = 0.2, respectively) and at 6 months (P = 0.4 and P = 0.9, respectively for pain and disability) and no difference was found between OMT/EG and the EG in the secondary outcomes during the same follow-up period (P > .05).

Conclusion

Outcomes of pain and functionality for patients in both groups were improved at 6 months. Our findings show that the combination of OMT and neck exercises for 4 weeks did not improve functionality and reduction of pain in patients with NCNP.

Introduction

Neck pain is a serious health problem with economic and social impacts, affecting up to two-thirds of adults at some point in their lives.¹ It is estimated that 4.5% of the population may present a substantial limitation of activities due to chronic neck pain. Studies show that up to 50% of people will have an episode of cervical pain at some point in their lives and may still have symptoms for 5 years after the first episode of pain.^{2, 3, 4} As a result, cervical pain represents a great health cost, mainly due to work absenteeism.⁵

Most neck pain has no specific or identifiable cause and, therefore, is labeled as non-specific chronic neck pain (NCNP).⁶ However, several aspects may contribute to NCNP, such as mechanical and biological conditions (age, sex, history of trauma, musculoskeletal disorders, and physical activity), as well as other factors related to psychosocial characteristics such as beliefs, fears, expectations, job satisfaction, anxiety, and depression. These factors are thought to determine the transition from acute to chronic pain.^5,7

There are several options for management of NCNP, including manual therapy, conventional physical therapy, drug treatment, exercise, and pain education, among others.^{8, 9, 10, 11} In recent years, manual therapy has shown a substantial increase of clinical trials to investigate the effectiveness of this practice, becoming a widely used approach.^{12, 13, 14, 15, 16} However, there is only moderate quality evidence supporting the use of manipulative treatments for neck pain able to prove that it is more useful than having no intervention or placebo treatment.^{17, 18, 19} Manual therapy is a favorable treatment option for cervical pain compared to conventional physical therapy and drug treatment.²⁰

Another approach used in conservative treatment of NCNP is strengthening and stretching exercises. In a systematic review, Freitas et al²¹ described improvement in pain and functionality in the exercise group when compared to the placebo group. Another systematic review concluded with moderate evidence that exercise impacts the improvement of pain, functionality, and satisfaction of the patient with NCNP.¹⁵ Manual therapy combined with exercise also showed better results when compared to manual therapy or exercises applied separately.^22,23

Osteopathic manipulative treatment (OMT) has been an option to treat neck pain.⁶ OMT consists of manual diagnostic techniques and manual treatments, following pre-established principles such as the inter-relationship between structure and function, intrinsic capacity for self-regulation and homeostasis, and also the concept of body unity.²⁴ The rational use of OMT in patients with chronic pain should not have a singular focus. It must integrate the whole body, interrelating structure and function to guarantee the best approach for each individual according to the somatic dysfunctions found.¹⁴

Current evidence has reported that OMT is more effective than placebo treatment or no treatment for pain and functionality in patients with NCNP.^6,25,26 A recent systematic review⁶ examined the effectiveness of OMT in reducing pain and improving functionality in individuals with NCNP, concluding that OMT reduced pain when compared to other groups (physical therapy or placebo). In a previously published article, we concluded that a 4-week OMT plus an exercise program improves pain and functionality when evaluating short-term (30 days) outcomes,²⁷ although there is a need to investigate the long-term impact of exercise associated to OMT in patients with NCNP, as well as the ideal dosage of the treatment. Therefore, the aim of this study was to evaluate long-term (3 and 6 months) effects of adding OMT to exercise for patients with NCNP.

Methods

Study Design

This study was a randomized, controlled, dual-blind clinical trial conducted between June 2017 and December 2018. After confirming eligibility criteria, participants were randomly assigned to an exercise group (EG) or an exercise in combination with an OMT group (OMT/EG).

Ethics

This study protocol was approved by the Ethics and Research Committee of the Federal University of Health Sciences of Porto Alegre under protocol number 1970517 and registered at Clinicaltrials.gov under registration NCT02956863. This study was reported in accordance with the guidelines from the Consolidated Standards of Reporting Trials on reporting randomized controlled clinical trials.²⁸ The methods utilized in the current study are similar to a previous publication.²⁷

Randomization

Prior to the study, a randomized list was generated, allocating the 90 participants to 1 of 2 treatment groups, EG or OMT/EG, using online software from RANDOM.ORG. Sequentially generated numbers, indicating which group each participant would belong to, were placed into 90 sealed envelopes. These envelopes were only opened after each participant had completed the full baseline assessment.²⁹ All participants were informed of the existence of the 2 groups, EG and OMT/EG. It was not possible for the therapists performing treatments to be blinded; however, the evaluators conducting assessments were blinded in terms of which group each participant was from.

Participants

Adults with NCNP were recruited through advertisements and social media throughout the period of the study. The baseline definition of NCNP is neck pain without any specific identifiable etiology (ie, infection, trauma, inflammatory disease, tumor, or radiculopathy).³⁰ Evaluators of eligibility criteria were blinded to the randomized list. Participant inclusion criteria were as follows: between the ages of 18 and 65; having persistent neck pain for at least 3 months; having a Numerical Pain Rating Score (NPRS) of 2 or more on a scale of 0 to 10; and having 10 or more out of a possible 50 points on the Neck Disability Index (NDI).³¹

Participants who had undertaken a neurological exam and presented at least 1 symptom, such as altered sensation in 1 or more dermatomes, decreased muscle strength, or reflex alteration, were excluded. Aside from these, individuals presenting 3 of the 4 following criteria from the clinical prediction rule for the diagnosis of cervical radiculopathy³² were also excluded: a positive Spurling test, a positive distraction test, a positive upper limb tension test A, and an ipsilateral cervical rotation of less than 60°. Participants who were pregnant, had reported a previous cervical surgery, or had a history and medical diagnosis for spondylolisthesis, spinal stenosis, cancer, or a degenerative osteo-myoarticular disease of the upper limbs were also excluded. And finally, participants who had received some form of manipulative therapy during the 3 months prior and/or who engaged in regular physical activity were also excluded.

Initial Evaluation

Data regarding eligibility criteria were collected during the initial assessment after each participant had read and signed the informed consent form approved by the Research Ethics Committee of the Federal University of Health Sciences of Porto Alegre. Psychological factors are known to be highly related to neck pain.³³ Depression and anxiety were assessed according to the Hospital Anxiety and Depression Scale.^34,35 This scale is comprised of 2 subscales of 7 items. Potential sub-scale scores range from 0 to 21; patients scoring greater than 8 on the depression scale were considered depressive, while patients scoring greater than 10 on the anxiety scale were considered anxious.

Interventions

EG

Participants undertook a supervised exercise program under guidance of an experienced physical therapist. This program comprised 1 session per week, in addition to home exercise over the course of 4 weeks. Exercise sessions were approximately 40 to 45 minutes, comprised of a 10-minute warm-up followed by 30 minutes of exercise, with a focus on stretching and strengthening the cervical muscles. The program included stabilization, flexion, extension, and rotation exercises for the cervical region, and self-mobilization targeting the deep neck muscles. The exercises had low isometric resistance and consisted of 3 sets of 10 repetitions in supine and seated positions. Participants were instructed to perform these exercises 3 times per week at home during the treatment period and during the 6-month follow-up, while ensuring that the exercises did not cause pain.

OMT/EG

The same exercise protocol and instructions were used for both groups during the treatment period and 6-month follow-up. In addition to the exercise program, participants in the OMT/EG group also received full osteopathic treatment once per week over the 4 week course, with each session lasting between 50 and 60 minutes. Ten registered osteopaths performed all treatments. At each appointment, participants received a full-body osteopathic examination in accordance with osteopathic principles, including clinical exams, observation, screening, palpation, and motion tests. The OMT sessions consisted of interviews focusing on pain location and osteopathic examination, and likewise, the intervention consisted of standard OMT. The osteopaths assessed regions and applied OMT to those that were considered dysfunctional. OMTs included direct (high-velocity, low-amplitude manipulation; muscle energy; and myofascial release), indirect (functional techniques and balanced ligamentous tension), visceral, and cranial techniques.²⁷ Osteopaths were free to assess the participant and choose which techniques to apply based on their own expertise, as well as treatments or advice, for example on diet, lifestyle, physical activity, counseling, coping strategies, and stress management.

Primary Outcomes

The NPRS and NDI were used to assess the primary outcomes, pain and disability. Range of motion (ROM) for cervical spine rotation, Pressure Pain Threshold (PPT), Pain Self-Efficacy, and Fear-Avoidance Beliefs Questionnaire (FABQ) were evaluated as secondary outcomes.

According to Young et al,³⁶ NPRS has an 11-point numeric pain intensity and it ranges from 0 (“no pain”) to 10 (“as much pain as possible”). The minimal clinically important difference in patients with chronic neck pain was identified as a change of 2 points or more on the scale.^12,37 “What was the worst pain you felt within the last week?” was the question asked to assess the patients’ pain.

To measure the patients’ limitations to manage activities of daily living related to neck pain, the NDI self-administered questionnaire was applied. According to Vernon and Mior,³⁸ higher scores show worse levels of disability, with the total score ranging from 0 to 50 points. In this validated questionnaire, each of the 10 items is rated on a 0- to 5-point scale.^38,39 The minimal clinically important change was reported from 3.5 to 9.5 points.^{40, 41, 42}

A handheld electronic pressure algometer (model DD-2000, Instrutherm) was used for PPT measurements. The device was calibrated before the tests, and it has a 1.0 cm² (base tip) probe. According to the trigger point map,⁴³ the assessment was taken in the suboccipital region in the midpoint between the occipital bone and the region corresponding to the C2 vertebra. For the PPT assessment, the participants remained laying prone on a table, and a perpendicular pressure was applied with the algometer. Participants were informed that when they sensed pain, the maximal pressure point was recorded, and no more force was applied. The mean of 3 measurements was used as the PPT score for each participant, with an interval of at least 30 seconds between each test.²⁵

The cervical mobility was measured with the participants in the sitting position. A cervical ROM device (CROM) was placed on the patient's head, and they performed cervical movements from left to right. Three measurements were taken, and the mean of the values represented the CROM score for each participant. The CROM device has good intratester and intertester reliability and validity.⁴⁴

A 16-item self-reporting questionnaire (FABQ) was used to evaluate the patients’ beliefs regarding the effect of physical activity and work on their pain. Two scales compose the questionnaire: “FABQ work scale” to assess fear-avoidance beliefs about work (7-item scale; score range 0-42) and “FABQ physical activity scale” to assess fear-avoidance beliefs about physical activity (4-item scale; score range, 0-24). Increased fear-avoidance beliefs are indicated by higher scores on both scales. The FABQ has good test-retest reliability.^{45, 46, 47, 48}

The patients’ confidence in carrying out normal activities despite the pain was assessed using the Pain Self-Efficacy questionnaire. It consists of 5 questions about how the patient manages the pain, and the answers range from 10% sure to 100% sure.⁴⁹

A blinded evaluator who did not know the participant test group did the assessments. The primary and secondary outcomes were collected at the following 3 moments: at 1 month (M1; baseline), 3 months (M2; 12 weeks after initiation of treatment), and 6 months (M3; 24 weeks after initiation of treatment) post-randomization.

Data Analysis

The expected 2-point difference for the main NPRS outcome was used to calculate the sample size of 70 participants, considering an SD of the NPRS of ± 1.6. The level of significance of 0.05 (0.5%) and statistical power of 80% were chosen, while a loss of 20% was acceptable.⁴⁰ Statistical analysis was performed in the SPSS version 20.0 (IBM Corp, Armonk, New York) by a blinded researcher. The independent t test was used to compare demographic data and initial assessment results. The data were checked for normality using 3 main factors; primarily visual inspection, followed by the SD size compared to the mean, as well as the values of the pre- and post-treatment variables using skewness and kurtosis analysis. Next, mean values and SD for each variable in the study was calculated. The effectiveness of the treatment was tested through generalized estimating equations. Data from all participants were assessed with intention-to-treat analysis considering time, group, and interaction between time-by-group effects. A 95% CI and α value of 5% (P ≤ .05.) were used in the analysis.

Results

Recruitment was carried out from June 2017 to December 2018, and the final 6-month follow-ups were completed in June 2019. Figure 1 shows the Consolidated Standards of Reporting Trials flow diagram of participants through the trial. Out of the 90 participants who were randomly assigned, 65 participants (72%) were followed up for 3 months, and 55 participants (61%) were followed up for 6 months. No adverse events were reported during the follow-up period. Thirteen participants from the OMT/EG were lost from follow-up (1 moved to other city; 12 gave up;), and 22 participants from the EG group (all gave up). Thus 55 participants (OMT/EG, n = 32; EG, n = 23) completed the study.

Fig 1.

Design and flow of participants through the trial.

Participants were mainly women (88.7%). Both groups were homogeneous in terms of demographic variables at baseline, each group had a mean age of 41.5 years (SD 11.5), and the baseline anthropometric variables were similar between the groups. Weight and height difference between the groups were 3.4 kg (P > .05) and 0.02 m (P > .05), respectively.

There was no significant difference in patient baseline characteristics between the groups in terms of clinical variables. NPRS, NDI, FABQ details are presented in Table 1.

Table 1.

Comparison Between Baseline Characteristics From Patients With Non-specific Chronic Neck Pain in the Exercise Group and in the Osteopathic Manipulative Treatment Group

	EG (n = 38)	OMT/EG (n = 45)	Difference Between Groups	P
Women, %	84.2 (n = 32)	93.3 (n = 42)	9.10	.18
Age, y	42.8 ± 9.8	40.2 ± 12.3	2.50	.3
Weight, kg	70.4 ± 10.60	67.0 ± 11.4	3.40	.1
Height, m	1.65 ± 0.07	1.63 ± 0.07	0.02	.5
NPRS	5.5 ± 1.6	5.7 ± 1.7	0.17	.6
NDI	18.87 ± 6	18.87 ± 5.1	0.00	.9
FABQ-W	20.5 ± 11	20.0 ± 10	0.40	.8
FABQ-PA	9.8 ± 7.5	11.1 ± 7	1.20	.4
HADS-A >10, %	65.8 ± 4	66.7 ± 4	0.90	.9
HADS-D >8, %	28.9 ± 4	24.4 ± 4	4.50	.8

Data expressed in percentage (%) and mean ± SD.

EG, exercise group; FABQ-FA, Fear-Avoidance Beliefs Questionnaire – Physical Active; FABQ-W, Fear-Avoidance Beliefs Questionnaire – Work; HADS-A, Hospital Anxiety and Depression Scale – Anxiety; HADS-D, Hospital Anxiety and Depression Scale – Depression; NDI, Neck Disability Index; NPRS, Numerical Pain Rating Scale; OMT, Osteopathic Manipulative Treatment.

There was a significant difference within groups in the reduction of the values obtained in NPRS (P < .05) and NDI (P < .05; Table 2).

Table 2.

Summary of Primary Outcomes Results: Numerical Pain Rating Scale, Pressure Pain Threshold and Neck Disability Index

Primary Outcome Measures	OMT/EG Mean ± SE	EG Mean ± SE	Between-Group Difference Mean ± SE CI (95%)	Between-Group P Value
NPRS
Baseline	5.7 ± 0.2	5.5 ± 0.2	0.2 ± 0.3 (−0.5 to 0.9)	.6
3 mo	2.7 ± 0.3	3.6 ± 0.4	−0.9 ± 0.5 (−2.0 to 0.1)	.1
6 mo	3.6 ± 0.4	3.0 ± 0.5	0.6 ± 0.7 (−0.8 to 1.9)	.4
Baseline/24 wk within-group difference, mean ± SE CI (95%)	2.1 ± 0.5 (1.1-3.1) P < .001a	2.5 ± 0.4 (1.5-3.4) P < .001a
PPT
Baseline	3.3 ± 0.4	2.7 ± 0.3	0.4 ± 0.5 (0.6-1.5)	.4
3 mo	3.1 ± 0.4	3.2 ± 0.5	−0.1 ± 0.6 (−1.4 to 1.2)	.8
6 mo	3.9 ± 0.5	3.5 ± 0.6	0.4 ± 0.8 (−1.2 to 2.1)	.6
Baseline/24 wk within-group difference, mean ± SE CI (95%)	0.6 ± 0.4 (−1.6 to 0.05) P = .06	−0.8 ± 0.7 (−2.2 to 0.6) P = .2
NDI
Baseline	18.9 ± 7	18.9 ± 9	0.0 ± 1.2 (−2.4 to 2.4)	.9
3 mo	10.7 ± 1.1	12.9 ± 1.5	−2.2 ± 1.9 (−6.2 to 1.5)	.2
6 mo	10.9 ± 1.4	10.8 ± 1.5	0.1 ± 2.1 (−4.0 to 2.2)	.9
Baseline/24 wk within-group difference, mean ± SE CI (95%)	7.9 ± 1.3 (5.3-10.5) P < .001a	8.0 ± 1.7 (4.5-11.5) P < .001a

Data expressed as mean ± SE.

3 mo, values after 12 weeks of treatment protocol; 6 mo, values after 24 weeks of treatment protocol; Baseline, baseline values; EG, exercise group; NDI, Neck Disability Index; NPRS, Numerical Pain Rating Scale; OMT/EG, osteopathic manipulative treatment group; PPT, Pressure Pain Threshold; SE, standard error.

^aP < .05 vs pre-values.

Primary Outcomes

The mean values at baseline, 3, and 6 months post-randomization, are shown in Tables 1 and 2, presenting the results from the intention-to-treat analyses of treatment effects for disability and pain intensity at 3 and 6 months.

Pain

There was no significant between-group difference in pain intensity at either 3 months (mean difference, −0.9; 95% CI, −2.0 to 0.1; P = .1) or 6 months (mean difference, 0.6; 95% CI, −0.8 to 1.9; P = .4) (Table 2).

Disability

There was no significant difference in disability between-group at either 3 months (mean difference, −2.2; 95% CI, −6.2 to 1.5; P = .2) or 6 months (mean difference, 0.1; 95% CI, −4.0 to 2.2; P = .9) (Table 2).

Secondary Outcomes

No significant difference was found for fear of physical activity or work and pain self-efficacy at 3 months or 6 months (Table 3).

Table 3.

Fear-Avoidance Beliefs Questionnaire and Pain Self-Efficacy Results

Primary Outcome Measures	OMT/EG Mean ± SE	EG Mean ± SE	Between-Group Difference Mean ± SE CI (95%)	Between-Group P Value
FABQ-W
Baseline	20.0 ± 1.5	20.5 ±1.82	−0.5 ± 2.4 (−5.2 to 4.3)	.8
3 mo	16.1 ± 2.1	19.7 ± 2.3	−3.5 ± 3.1 (−9.8 to 2.7)	.2
6 mo	16.4 ± 2.4	18.0 ± 2.4	−1.6 ± 3.4 (−8.3 to 5.1)	.6
Baseline/24 wk within-group difference, mean ± SE CI (95%)	3.6 ± 1.8 (−.11 to 7.3) P = .9	2.4 ± 2.1 (−1.6 to 6.6) P = .2
FABQ-FA
Baseline	11.1 ± 1.0	9.9 ± 1.2	1.2 ± 1.5 (−1.8 to 4.3)	.4
3 mo	9.6 ± 1.24	8.5 ± 1.4	1.1 ± 1.8 (−2.5 to 4.7)	.5
6 mo	10.7 ± 1.3	7.0 ± 1.3	3.7 ± 1.9 (−.12 to 7.2)	.6
Baseline/24 wk within-group difference, mean ± SE CI (95%)	0.4 ± 1.3 (−2.2 to 3.1) P = .7	2.8 ± 1.5 (−.08 to 5.8) P = .5
Pain self-efficacy
Baseline	352.6 ± 14.1	319.7 ± 16	32.9 ± 2.1 (−9.0 to 74.8)	.1
3 mo	405.7 ± 18.7	351.9 ± 35.8	54.7 ± 40.4 (−24.5 to 134.05)	.1
6 mo	415.0 ± 19.3	440.0 ± 16.1	−25.0 ± 25.2 (−74.4 to 24.4)	.3
Baseline/24 wk within-group difference, mean ± SE CI (95%)	−62.3 ± 2.1 (−104.2 to −20.4) P = .004a	−120.2 ± 21.0 (−161.5 to −79.0) P < .001a

Data expressed as mean ± SE.

3 mo, values after 12 weeks of treatment protocol; 6 mo, values after 24 weeks of treatment protocol; Baseline, baseline values; EG, exercise group; FABQ-FA, Fear-Avoidance Beliefs Questionnaire – Physical Active; FABQ-W, Fear-Avoidance Beliefs Questionnaire – Work; OMT/EG, osteopathic manipulative treatment group; SE, standard error.

^aP < .05 vs pre-values.

Discussion

This study, as far as we know, is the first randomized controlled trial to use OMT plus exercises with the aim of evaluating the 6-month long-term effectiveness of associating OMT and neck strengthening and stretching exercises in pain and functionality in participants with non-specific neck pain. We found no statistically significant differences in the primary and secondary outcomes between groups at 12 weeks and 24 weeks after the treatment. However, our data analysis suggests a significant reduction in pain intensity and improvement in functionality in both groups, comparing baseline to 12 weeks and 24 weeks.

In a previous paper by our research group, we investigated the immediate effect of the association of a 4-week OMT plus neck exercises.²⁷ We found a significant reduction in pain intensity and disability in both groups compared to baseline, which corroborates with the present study results. We also have demonstrated that OMT combined with exercise led to immediate reductions in pain and improvement in functionality when compared to the exercise group. However, these differences did not persist on a 6-month long-term basis.

Both OMT/EG and EG groups presented significant improvements in pain and functionality outcomes. These results corroborate the findings of several recent studies, which demonstrate that there is no difference between groups in long-term improvement of pain and functionality with the use of manual therapy plus exercises.^7,17,50 However, our results demonstrate that there is a benefit for patients with chronic neck pain in reducing pain and improving function when using neck stretching and strengthening. Furthermore, manual therapy combined with exercises proved to be effective for medium and long-term improvements in pain, function/disability, and global perceived effect compared to no treatment in patients with chronic neck pain.^17,51

The treatment adherence was 71% in OMT/EG and 51% in EG. Adherence was higher in the OMT/EG group, which may have been motivated by the contact with the osteopath. Many studies indicate that patient-provider interaction is a positive factor in outcomes and treatment adherence.⁵⁰ These results are compatible with other outcomes found in different articles, in which the adherence in treatment programs for neck and low back pain converge around 50%.^50,52

We must consider 2 important aspects that may have influenced the results. First, the lower adherence in the EG group may have impacted the results because it is known that groups with the greatest loss of follow-up tend to be groups with lower morbidity. Another aspect to consider regards the OMT dose; future studies should consider a higher dose and frequency of treatment so that we can observe the medium-term and long-term effects of OMT.

Our results corroborate the findings of several recent studies that found that chronic neck pain, like other musculoskeletal chronic disorders, could not benefit from manual therapy over a long period, only in a short period.⁵³

Strengths and Limitations

The strengths of this study were that it was prospectively registered and incorporated design features known to minimize bias, such as concealed allocation and intention-to-treat analysis. This trial represented clinical practice as we allowed the osteopaths in the individualized intervention the freedom to deliver the treatment in line with their clinical assessment and available resources.

Considering the total number of participants, 38% did not complete the treatment, only 72% completed the 3-month follow-up, and only 61% of them completed the 6-month follow-up. Although this loss of follow-up was not significantly different between groups, we acknowledge that non-adherence can lead to unmeasured bias in intention-to-treat results. Information about general exercise practice was not controlled within the 2 groups during the 6-month follow-up. This RCT observes the same intervention, but the absence of sham treatment in the control group could misinterpret the results.

Future research needs to explore an analysis of the influence of a higher frequency of treatment and include a subgroup analysis to determine the individuals that are most likely to benefit from the osteopathic treatment.

Conclusion

In conclusion, after 6 months, both treatment groups reported improvement in pain and functionality. Our results do not support the hypothesis that the combination of 4-week OMT plus neck strengthening and stretching exercises would result in long-term improvement of functionality and reduction of pain in patients with non-specific chronic neck pain rather than patients who had only exercise.

Funding Sources and Conflicts of Interest

No funding sources or conflicts of interest were reported for this study.

Contributorship Information

Concept development (provided idea for the research): S.G., L.S.S.

Design (planned the methods to generate the results): S.G., L.S.S., T.M., G.P.J.

Supervision (oversight, organization and implementation): T.M., G.P.J.

Data collection/processing (experiments, organization, or reporting data): S.G., L.S.S., T.R.R.S., C.S.S.R.

Analysis/interpretation (analysis, evaluation, presentation of results): S.G., L.S.S., T.R.R.S., C.S.S.R.

Literature search (performed the literature search): S.G., L.S.S.

Writing (responsible for writing a substantive part of the manuscript): S.G., L.S.S.

Critical review (revised manuscript for intellectual content): T.M., G.P.J.

Practical Applications.

• •This study evaluated the long-term effects of adding osteopathic manipulative treatment (OMT) to neck exercises compared to exercises alone for individuals with non-specific chronic neck pain.
• •No statistically significant differences in pain intensity or disability were found when OMT/EG was compared to EG alone at 3 months and at 6 months for pain and disability.
• •No difference was found between OMT/EG and the EG in the secondary outcomes during the same follow-up period (P > .05).

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