An international consensus on gaps in mechanisms of forced-based manipulation research: findings from a nominal group technique

ABSTRACT

Force-Based Manipulation (FBM) including light touch, pressure, massage, mobilization, thrust manipulation, and needling techniques are utilized across several disciplines to provide clinical analgesia. These commonly used techniques demonstrate the ability to improve pain-related outcomes; however, mechanisms behind why analgesia occurs with these hands-on interventions has been understudied. Neurological, neuroimmune, biomechanical, neurovascular, neurotransmitter, and contextual factor interactions have been proposed to influence response; however, the specific relationships to clinical pain outcomes has not been well established. The purpose of this study was to identify gaps present within mechanism-based research as it relates to FBM. An international multidisciplinary nominal group technique (NGT) was performed and identified 37 proposed gaps across eight domains. Twenty-three of these gaps met consensus across domains supporting the complex multisystem mechanistic response to FBM. The strength of support for gaps within the biomechanical domain had less overall support than the others. Gaps assessing the influence of contextual factors had strong support as did those associating mechanisms with clinical outcomes (translational studies). The importance of literature investigating how FBM differs with individuals of different pain phenotypes (pain mechanism phenotypes and clinical phenotypes) was also presented aligning with other analgesic techniques trending toward patient-specific pain management (precision medicine) through the use of pain phenotyping.

Introduction

Force-Based Manipulation (FBM) is defined as passive application of mechanical force to the outside of the body with therapeutic intent, often as part of pain management care (e.g. low-back pain), rehabilitation care, or general wellness and disease prevention. [1] Examples of FBM include light touch, pressure, massage, mobilization, thrust manipulation, adjustment, and needling techniques. These techniques may be provided through direct contact, instrument assisted application of force, or mechanical/machine driven force application. These commonly used techniques have demonstrated the ability to improve outcomes in patients dealing with pain complaints [2–5]. Neurological, neuroimmune, biomechanical, neurovascular, neurotransmitter, and contextual factor interactions have been indicated as mechanisms of action occurring with FBM [6–8]; however, the extent which each of these mechanisms correlate with clinical outcomes has not been well established.

Recent literature has outlined that the specifics of hands-on interventions (location and direction of force) may be less important than previously understood which further warrants a better understanding of the mechanisms behind FBM [9–13]. A better understanding of the mechanistic effect of FBM along with the associated clinical responses would stimulate progress toward better identifying appropriate candidates for these techniques. The first step in this process is determining the status of the literature and developing a plan moving forward on what gaps are present that need to be further investigated. A literature review would summarize previous works; however, may fall short in identifying novel gaps which have not been established. A consensus-based technique utilizing current experts within the area of study addresses this concern. The purpose of this study was to identify gaps present within mechanism-based research as it relates to FBM.

Methods

Study Design: This study utilized a five-stage virtual nominal group technique (vNGT) [14]. The vNGT was performed in November 2022. Nominal group techniques are a form of consensus research ideal for obtaining consensus on controversies and gaps within a topic area, as well as developing potential solutions and priorities in addressing the identified problems. This format demonstrates advantages over other forms of consensus research including the Delphi technique and focus groups by encouraging both direct communication and equal representation between participants [15,16]. This study was exempt by the Institutional Review Board of Duke University prior to performing (Pro00111288).

Nominal Group Technique Participants: NGT encourages a small group (5 to 9 individuals) who have been identified as experts in the area of study to collaborate on a given topic [14]. The strength of any consensus-based research relies on the quality and representation of the experts chosen to participate. In this study, NGT participants were identified by their publication history and/or educational/leadership roles in national or international organizations promoting FBM. Force-Based Manipulation techniques are utilized across several disciplines including but not limited to massage therapists, physical therapists, chiropractors and osteopaths, therefore a multidisciplinary panel of experts was utilized.

Study Procedure: Participants were provided with pre-work prior to the vNGT including: 1) Outline of NGT format including information on each of the five stages [14]. 2) Four recent articles which have touched on gaps within FBM mechanisms research including the 2019 National Institute of Health (NIH) workshop summary [17–21]. 3) The definition of force-based manipulation (FBM) per NIH initiative [1]. 4) Proposed domains which have been recommended as mechanisms of FBM. The proposed mechanistic domains included: neurophysiological mechanisms, psychophysical mechanisms, neuroimmune mechanisms, biomechanical mechanisms, contextual factors influencing mechanisms and translation of mechanisms to clinical outcome. Each participant was asked to contemplate and prepare gaps within these and any other suggested areas prior to the meeting.

The study protocol followed the five-stage NGT process outlined by Potter et al. [14] The platform utilized was Zoom (Zoom Video Communications, San Jose, CA, US). The session was moderated by a researcher with a background in orthopedic manual therapy (OMT) mechanisms research and prior experience with vNGT research and moderation. The synchronous component of the vNGT lasted 2 h in duration. The five-stage NGT protocol is outlined in Table 1.

Table 1.

Stages of virtual Nominal group technique.

Stage one (Intro & Explanation)	Introduction of each individual including their area of study/background. Explanation of the purpose of the meeting and re-education on the stages to be expected. Participants had a chance to ask any initial questions for clarification regarding the pre-work.
Stage two (Silent Idea Generation)	The specific goal of the NGT was presented to the workgroup as ‘prioritizing gaps in mechanisms research for force based manipulation’. All participants were asked to upload their ideas onto a shared Google document (Google Corp, CA, USA). A blank document with columns representing the proposed mechanistic domains was presented to the participants to fill in during the NGT session. Participants were asked to silently generate ideas without discussion. A total of 10 minutes was provided.
Stage three (Sharing Ideas)	Participants were invited to share their ideas while the moderator shared the document on the screen so that all participants could follow along. Each participant offered one idea at a time while this stage continued in a round robin format until all ideas had been presented. No debate occurred during this stage.
Stage four (Group Discussion)	Participants were invited to seek explanation and clarification on any of the proposed gaps produced during stage three. The moderator ensured that all individuals were heard and that the overall tone remained non-judgmental. Participants were able to suggest modifications to current items, proposal of new items, and relocation/consolidation of items if similar gaps were present. Edits to proposed gaps were only able to occur if agreed upon by the individual who defined the gap.
Stage five (Voting)	Participants were asked to vote on the gaps identified in stage four using a 4-point Likert scale (Strongly Disagree, Disagree, Agree, Strongly Agree). This was completed several hours following completion of the vNGT. Participants were provided a web link to voting through the Qualtrics web-based survey system (Seattle, WA, US). The questionnaire was stored on a password protected server through Qualtrics software. This company is a common vendor used for survey research and has significant data protection policies in place.

Data analysis

SPSS version 29.0 (IBM Corp, Armonk, NY) was utilized for all quantitative analysis. Scores were divided into two categories based on descriptive identifiers: The tally of ‘“Strongly Disagree”’ and ‘“Disagree”’ represent the percentage of scores in the ‘not recommended’ category, meaning that the proposed gap is not recommended. On the contrary, the tally of ‘Strongly Agree’ and ‘Agree’ represent the percentage of scores in the ‘recommended’ category, meaning that the gap is recommended. Consensus was determined a priori to be reached if at least 75% of the respondents scored the gap as either ‘not recommended’ or ‘recommended’ as recommended by previously established guidelines [22]. A composite score to establish the strength of the recommendation for each proposed gap was calculated based on the following formula:

CS = (n1 × (−2)) + (n2 × (−1)) + (n3 × 1) + (n4 × 2)

CS = composite score

n1 = number of respondents answering ‘Strongly Disagree’ with gap in OMT mechanisms research

n2 = number of respondents answering ‘Disagree’ withgap in OMT mechanisms research

n3 = number of respondents answering ‘Agree’ with gapin OMT mechanisms research

n4 = number of respondents answering ‘Strongly Agree’with gap in OMT mechanisms research

Results

Twelve experts in the field of manual therapy mechanisms research were identified via literature review. Eight international participants agreed to be included within the vNGT representing four professions (Physical Therapy, Chiropractic, Osteopathy, and soft tissue practitioners) and five different countries. Participants combined for a total of 100 published works on OMT mechanisms along with several years of teaching experience within the same domain. Characteristics and justification of expertise are presented in Table 2.

Table 2.

Nominal group technique Participants’ background.

Clinical Background	Research Training and Background	Location	Number of Publications involving Mechanisms Research in FBM	Number of years providing education or serving in leadership roles related to FBM
Osteopathy	Cognitive Science	Malta	10	29
Physical Therapy	Neuroscience/Motor Control	USA	28	17
Chiropractor	Neurophysiology/Biomechanics	Denmark	10	7
Physical Therapy	Biomechanics/Rehabilitation Sciences	Canada	12	6
Chiropractor	Clinical education/pathophysiology	Canada	15	17
Physical Therapy	Rehabilitation Science	USA	22	18
None	Biomechanics	Canada	6	12
Soft Tissue Therapist	Massage/Sports Therapy	UK	0	15

No questions or concerns were posed following stage one/introduction. Forty-Six potential gaps were identified following stage two. During stage three, these gaps were presented to the group. The question was posed during this stage whether ‘dry needling’ should be considered as a form of force-based manipulation. While outside the scope of this study, it was noted that this was a concern amongst several participants. It was decided that the current study would utilize the definition of FBM provided by NIH (including needling techniques), which was outlined previously within this text, in defining gaps in FBM mechanisms research. During stage four, participants agreed on editing, removal, and consolidation of gaps. Completion of stage four presented 37 total gaps: four in neurological mechanisms research, four in neuroimmune mechanisms research, seven in biomechanical mechanisms research, two in neurovascular mechanisms research, one in neurotransmitter mechanisms research, three in translational mechanisms research, nine in contextual factors influence on mechanisms research, and seven that did not align with any of these previously stated domains.

Participants were asked to vote on these 37 gaps with all voting being completed within 1 week of the vNGT. Results of the voting are presented in Table 3. Twenty-three (62.2%) of the proposed gaps met consensus supporting: two in neurological mechanisms research, two in neuroimmune mechanisms research, one in biomechanical mechanisms research, one in neurovascular mechanisms research, one in neurotransmitter mechanisms research, three in translational mechanisms research, six in contextual factors influence on mechanisms research, and seven others. The remaining 14 (37.8%) of the proposed gaps did not meet consensus. None of the proposed gaps met consensus opposing support.

Table 3.

Agreement or disagreement with GAPS in force-based mechanisms research.

	Composite Score (Range: −16 to 16)	Consensus Status
Gaps in neurological mechanisms research (fMRI etc.)
Developing a model that uses (EEG, central reflexes, etc) to identify both spinal and supraspinal mechanisms associated with pain modulation.	11	CM
Studies investigating by fMRI how people with different pain types (nociceptive, nociplastic, neuropathic etc) respond to FBM	6	CM
Neuroimaging studies investigating the effects of FBM on the ANS, nociceptive and interoceptive systems in both healthy individuals and chronic pain patients (e.g. musculoskeletal related, visceral)	5	CNM
Studies describing the cellular and molecular responses to different types and dosages of FBM	4	CNM
Gaps in neuroimmune mechanisms research (inflammatory/anti-inflammatory mediators etc.)
Studies investigating how various FBMs impact the inflammatory process and how putative inflammatory mediators affect pain pathways.	9	CM
Studies investigating differences in inflammatory parameters and other mechanisms of FBM including long term follow up studies with characteristics of applied force being considered.	6	CM
Studies investigating the effects of FBM on neurogenic inflammation	1	CNM
Studies (human) investigating different FBM and their effects in formation of fibrosis post inflammation and in tissue repair (scar tissue formation post-surgery)	1	CNM
Gaps in biomechanical/kinematic mechanisms research (tissue movement, fluid loading, etc)
Studies that link biomechanical and neurophysiological responses (both segmentally/regionally and globally)	10	CM
Studies that evaluate the effects of FBM on regional and global neuromechanical function	5	CNM
Studies that investigate the potential of FBM to create tissue damage and injury	4	CNM
Studies that use in silico approaches (e.g. FEM) to identify structures loaded as a result of FBM.	3	CNM
Studies that determine how FBM changes regional and global movement – optimally linking this with direct measurements	3	CNM
Studies that explore the ‘plausibility’ of FBM to cause reported adverse events; trying to replicate AEs in the lab. e.g. can we ‘cause’ a stroke in a lab using FBM?	1	CNM
Studies investigating the effects of FBM on passive physiological and accessory motion	0	CNM
Gaps in neurovascular mechanisms research (sympathetic response etc.)
Studies exploring the interaction of ANS effects and descending pain modulatory effects of FBM	11	CM
Studies exploring direct evidence for the action of FBM on the ANS, specifically in terms of demonstration of neurotransmitter levels and microneurographic studies	4	CNM
Gaps in neurotransmitters mechanisms research (serotonin, B endorphin, etc.)
Studies investigating how meaningful neuroendocrine effects may be for pain, inflammation, or movement	5	CM
Gaps in translational mechanisms research (Correlating mechanisms to clinical outcomes)
Studies that Determine if and how much contextual factors can change mechanisms of FBM	13	CM
Studies clarifying direct versus behavioral assessment. (ie. Do findings in animal studies have relevance to humans.)	10	CM
Studies that investigate whether a change in any mechanisms have an impact on clinical outcomes.	7	CM
Gaps in contextual factors influence on mechanisms (contextual factors effect on mechanisms)
Studies that explore improved sham for different types of FBM interventions	10	CM
Studies investigating the role of top-down processes on the effects of FBM (language, imagery, context, etc)	9	CM
Studies that can measure contextual effects differences between different types of FBM (do contextual effects have a different influence for different FBM) ie. how do contextual effects influence dynamic prolonged touch vs massage vs SMT	9	CM
Studies that investigate how contextual factors are used when performing FBM in practice	8	CM
Studies that identify the critical components of different types of FBM that affect the mechanistic response	9	CM
Studies that systematically vary the context while keeping treatment parameters consistent.	6	CM
In studies of FBM and inflammatory parameters, tighter control of contextual as well as technical factors are needed.	4	CNM
Studies that map force input through to biochemical responses	2	CNM
Studies investigating the physiological effects of gentle FBM on pre-terms and newborns (with little top-down/expectations etc)	−3	CNM
Gaps in other areas
Studies that define the dose response of FBM on mechanistic physiological and behavioral outcomes	16	CM
Studies that define key parameters of dose of different types of FBM	15	CM
Studies investigating if different patient phenotypes (based on experimental measurements) respond differently to different FBM	11	CM
Studies that identify aberrant pain mechanisms and investigate the effects of FBM on these mechanisms (Example: Determine the modulatory effects of soft tissue FBM on TRPV1 receptors activation)	8	CM
Studies investigating how transduction of FBM interventions occur at the cellular molecular level? (Precise mechanisms from the activation of cellular components in tissues, to peripheral and central neuronal activation)	6	CM
Studies investigating the effects of FBM on neuropathic pain mechanisms	6	CM
Studies investigating the effects of deep slow dynamic touch vs other FBM on interoception	3	CM

FBM= Force Based Manipulation; EEG= Electroencephalogram; fMRI= Functional Magnetic Resonance Imaging; ANS= Autonomic Nervous System; FEM= Finite element method; SMT= Spinal Manipulative Therapy; CM= Consensus Met (>75% Agreement); CNM= Consensus Not Met (<75% Agreement)

Composite scores representing the strength of recommendation revealed studies that define key parameters of dose with different types of FBM, and dose-response of FBM on mechanistic physiological and behavioral outcomes were ranked the highest amongst all identified gaps.

Discussion

An NGT is a recommended form of consensus research within healthcare [16,23]. The validity of recommendations from any form of consensus research relies on the expertise of the participants. The current study recruited individuals who have demonstrated advanced knowledge of one or more of the mechanisms associated with FBM. Emphasis was placed on geographical and professional representation.

Overall results of this study support the complex multisystem mechanistic response to FBM as demonstrated by the distribution of the proposed gaps. The biomechanical domain had less support overall as demonstrated by only one of the seven proposed gaps reaching consensus. Three gaps that did not achieve consensus in the biomechanics domain were focused on tissue loading and injury. While it is necessary to understand tissue loading and injury potential for studying adverse events related to FBM, these lines of inquiry are less likely to be connected to mechanisms underlying the therapeutic benefit of FBM. Other gaps that did not achieve consensus in the biomechanics domain were connected by a theme of passive and active movement of joints and could have been perceived to be disconnected from contemporary theories regarding mechanisms of FBM that favor neurophysiological explanations. A recent review assessed the biomechanical parameters of spinal manipulation and suggested further gaps within this domain [24]. Gaps identified by the review were specifically focused on using force-time parameters of spinal manipulation to define dosage of treatment. Similarly, many of the gaps identified by the current NGT across all domains are predicated on quantifying dosage of treatment and/or controlling the force-time parameters of FBM in experimental studies.

All three gaps relating to the importance of translational research (associating mechanistic response to clinical outcomes) reached consensus. This is in agreement with a recent review which recommended a gap within this area related to spinal manipulation [25]. Several other associative themes were noted as well including association between mechanistic responses (autonomic with neurological, biomechanical with neurophysiological, neuroendocrine, and inflammatory), association between dose with mechanistic response (neurophysiological, neuroimmune) and association between patient contextual factors and mechanistic responses (physiological, immune). Contextual factors have been a recent emphasis in FBM literature as they have shown importance in moderating treatment outcomes [26–29]. The means through which these factors interact with the mechanisms of FBM however are not clear, which is demonstrated by the resultant gaps identified within this study.

Another theme demonstrated was the importance of literature investigating how FBM differs with individuals of different pain phenotypes (pain mechanism phenotypes and clinical phenotypes). This aligns with other analgesic techniques trending toward more patient-specific pain management through the use of pain phenotyping [30].

Summary

This study identified gaps within the literature related to the mechanisms of FBM and may act to guide future mechanistic and translational research. Rigorous mechanistic and translational research investigating these gaps in knowledge should look to assess multiple domains and influencing factors when possible, to assess interaction. The multidisciplinary consensus represented by this study should align researchers investigating FBM across different disciplines on research priorities. A more thorough understanding of mechanisms associated with FBM and factors influencing them will support more precise application of techniques to those who are most likely to respond. Precision application of FBM is far from fruition, however we hope the results of this study act as a step toward this long-term goal.

Limitations

Limitations on representation were present within the expert panel. Geographical limitations were presented as five participants (63%) were located within North America (USA and Canada). Participation of only one Osteopath and one soft-tissue practitioner may not be representative of their respective professions therefore limitations in representation are present.

Biographies

Damian L. Keter is a clinician and clinical researcher at the Cleveland VA Medical Center where he also serves as a mentor within their Physical Therapy Orthopaedic Residency program. He earned his Doctorate of Physical Therapy followed by his Philosophy Doctorate in Health Sciences where he investigated pain phenotyping in Orthopaedic Manual Therapy. He is a Board Certified Orthopaedic Clinical Specialist and holds certifications in dry needling and chronic pain rehabilitation. He serves as a member of the Department of Veterans Affairs National Biopsychosocial pain mentoring program and a National Institute of Health workgroup on force-based manipulation. He has published several peer-reviewed works on education and clinical topics related to pain and manual therapy.

Jennifer A. Bent is a board-certified orthopedic physical therapist with over 10 years of experience in the management of acute and chronic musculoskeletal conditions at Duke University Healthcare System using a contemporary approach to rehabilitation. She completed her Bachelor of Science in Exercise Science with a minor in Sport Coaching from UNC-Greensboro, her Master’s degree in Physical Therapy from Winston Salem State University. She is a Fellow of the American Academy of Orthopedic Manual Therapists and a graduate of the Myopain Seminar Series.

Joel E. Bialosky is a Clinical Professor in the Department of Physical Therapy at the University of Florida in Gainesville, Florida. He received a bachelor’s degree in physical therapy from Ithaca College in 1990 and a master’s degree in musculoskeletal physical therapy from the University of Pittsburgh in 1998. He graduated from the University of Florida with a PhD in Rehabilitation Science in 2008 with his research interests focused on the mechanisms of manual therapy in the treatment of musculoskeletal pain. His current research program is focused on 1.) contextual mechanisms of manual therapy and 2.) neuroplastic changes in pain associated with musculoskeletal disorders and their response to common rehabilitation interventions.

Carol A. Courtney is Professor at Northwestern University Department of Physical Therapy and Human Movement Science and serves as the Associate Chair for Clinical Post-Professional Studies. She received a Bachelor of Science in Physical Therapy from Washington University in St Louis, Master of Science from the University of South Australia and Louisiana State University, and a PhD from the University of Miami. Dr. Courtney is a licensed physical therapist and athletic trainer, and has been recognized as a Fellow of the American Academy of Orthopaedic Manual Physical Therapists. She was recently named a Catherine Worthingham Fellow of the American Physical Therapy Association.

Jorge E. Esteves is an osteopath and cognitive scientist with a special interest in chronic musculoskeletal pain. He is currently professor of osteopathy and deputy director of Malta ICOM Educational, honorary professor at the University College of Osteopathy in London and researcher at the Collaboration for Osteopathic Medicine Research in Italy. His current research interests are focused on reconceptualizing osteopathic care under active inference and enactivist frameworks.

Martha Funabashi is a clinical research scientist and associate professor at the Canadian Memorial Chiropractic College and an adjunct professor at the Universitè du Quèbec à Trois-Rivières and at Parker University. She has a bachelor’s degree is Physiotherapy, a master’s degree in Neurosciences and a PhD in Rehabilitation Sciences. She did a post-doctoral fellowship in patient safety. Martha’s research interests and passion include the biomechanics, underlying mechanisms and safety of manual therapies, with a focus on spinal manipulative therapy and spinal mobilization.

Dr. Samuel J. Howarth is an Associate Professor, Director of Human Performance Research and holds the McMorland Family Research Chair in Mechanobiology at the Canadian Memorial Chiropractic College. He also holds adjunct positions at multiple Canadian universities. His current research is directed toward biomechanical analysis of human movement focusing on functional tasks used in daily life and clinical practice. Part of this work is dedicated to understanding how clinicians perform force-based manipulation, and how force-based manipulation affects physical function.

H. Stephen Injeyan is a professor for the Department of Research and Clinical Education at Canadian Memorial Chiropractic College (CMCC). He has a MSc and a PhD in the area of microbiology specializing in Parasitology from the Institute of Parasitology of McGill University. He has many years of teaching and research experience in the area of cell biology and microbiology. He received his qualification as a Doctor of Chiropractic in 1984 at CMCC. He has held a faculty position with duties and activities in research, teaching and Clinical Education for 42 years, at the same time holding a full-time clinical practice. His primary focus of research in the chiropractic area has been on the exploration of the effects of spinal manipulation on selected parameters of the immune response. Specifically, he has led the effort in understanding the effects of a manipulative intervention on inflammatory changes in patients with low back pain and his team has published several articles in this area. He has also collaborated with others on topics relevant to public health and chiropractic education.

Anna Maria Mazzieri is a Soft Tissue Therapist and Educator with a special interest in the mechanisms of Massage, Manual Therapy and the contextual effects involved. She holds a Diploma in Soft Tissue Therapy followed by a Bachelor of Science with Honours in Sports Therapy by the University of St. Mark and St. John and waiting to start Master’s in Neuroscience. In clinical practice since 2002 and providing education since 2008 through The School of Soft Tissue Therapy which she founded. Anna Maria leads a team of tutors to deliver the BTEC Level 5 Diploma in Soft Tissue Therapy as well as creating and delivering post-graduate courses in evidence based manual and massage therapy approaches. She sits on the board of the Institute of Sports and Remedial Massage and has driven the introduction of Evidence Informed Practice into the Diploma curriculum and raised the benchmarks of education and practice. Anna Maria has been involved in several studies on mechanisms including a recent paper on Manual Therapy Framework for different pain phenotypes.

Dr. Casper Glissmann Nim holds the position of Assistant Professor at the Department of Sports Science and Clinical Biomechanics, as well as the Department of Regional Health Research at the University of Southern Denmark. Additionally, he is a Senior Researcher at the Spine Centre of Southern Denmark, University Hospital of Southern Denmark. His research interests revolve around manual therapy, with a particular emphasis on how the specificity of intervention impacts treatment outcomes.

Chad E. Cook PT, PhD, FAPTA is a Professor in the Department of Orthopaedic Surgery in Duke University. He also has appointments in Population Health Sciences and the Duke Clinical Research Institute. Dr. Cook is an NIH and DoD funded researcher and is the Director of the Duke Center of Excellence in Manual and Manipulative Therapy.

Funding Statement

No funding sources to disclose.

Disclosure statement

Chad Cook is the Director of the Center of Excellence in Manual and Manipulative Therapy at Duke University and a portion of his salary is supported by that role. Chad published a book on OMT and a course with AGENCE EBP on Manual Therapy in which he receives royalties. He is also a consultant for the Hawkins Foundation, Zimmer Biomedical, and Akron Children’s.

All remaining authors have nothing to disclose

The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs or the United States government.