Promoting Biopsychosocial Assessment of Phantom Limb Pain in Veterans With Amputation

Abstract

Pain management is a focus of rehabilitation for Veterans after amputation, and occupational therapy practitioners play a key role in providing this care as part of an interdisciplinary team. However, the evaluation and treatment of phantom limb pain (PLP) after amputation lack guidance with respect to best practices. There is a need for improved identification of factors that contribute to PLP so that treatment targets can be identified. In this column, we discuss the application of the biopsychosocial model to the clinical management of PLP as part of comprehensive care for Veterans after amputation. We present factors associated with PLP, categorized using the biopsychosocial model, and discuss specific considerations for Veterans. We also provide recommendations for the biopsychosocial evaluation of PLP in occupational therapy practice, and we highlight the value of involving occupational therapists in interdisciplinary health care teams. Furthermore, we recommend continued evaluation and discussion to monitor changes in PLP and its associated factors over time.

The authors present factors associated with phantom leg pain and discuss specific considerations for Veterans, including highlighting the value of involving occupational therapists in interdisciplinary health care teams.

Recent clinical practice guidelines for the rehabilitation needs of Veterans and military service members after amputation include a focus on pain management (U.S. Department of Veterans Affairs & U.S. Department of Defense, 2024). Veterans experience higher rates of chronic pain than civilians; moreover, they often react to and manage pain differently from civilians (Hitch et al., 2020; Taylor et al., 2024). As rates of amputations in Veterans rise, effective and evidence-based postamputation pain care will increasingly be a priority (Cai et al., 2021).

One important but underdeveloped clinical component of postamputation pain management for Veterans is the evaluation and treatment of phantom limb pain (PLP), a unique form of discomfort felt in the part of the limb that no longer remains. PLP requires interdisciplinary medical management and expertise, with a critical role served by occupational therapy practitioners. Occupational therapists conduct comprehensive evaluations of pain’s interference with daily activities and recommend treatment strategies that focus on occupational performance (Hesselstrand et al., 2015). Without clear guidance for evaluation, though, providing effective, evidence-based care can be challenging.

The biopsychosocial model is a valuable framework that can help structure the occupational profile as part of the initial evaluation and then guide the assessment and treatment of PLP in Veterans with amputation. The biopsychosocial model, which has been applied to the clinical management of other types of pain (Miaskowski et al., 2020), depicts pain as a multidimensional experience that can be influenced by the complex interactions among factors that fall into three main categories: (1) biological, (2) psychological, and (3) social (Figure 1). This model considers how the Veteran responds to pain, how pain affects their mental well-being, and how environmental and situational factors influence their pain experience (Bevers et al., 2016). Each of these aspects can become treatment targets within interdisciplinary care. Use of the biopsychosocial model fosters comprehensive, whole-health evaluation and management of the Veteran.

Figure 1.

The biopsychosocial model of phantom limb pain.

A whole-health approach to PLP first requires a better understanding of the factors that can influence this type of pain in Veterans as well as how those factors fit within the context of the biopsychosocial model. We argue there is an underrecognition of the intersection of the factors that contribute to a Veteran’s PLP that may be targetable in therapy as part of treatment provided by a collaborative interdisciplinary team. In this column, we present a categorization of factors that is based on the biopsychosocial model, with considerations for Veterans; make recommendations for the application of this model to occupational therapy care as part of treatment provided by an interdisciplinary health care team; and discuss continued reassessment of PLP and its associated factors over time for successful lifelong rehabilitation. With this understanding, occupational therapy practitioners can apply this model to patient care, supporting Veterans’ overall recovery, wellness, and adaptation after amputation.

Biological, Psychological, and Social Factors That Influence PLP

The biological factors that are associated with PLP span various aspects of health. Most commonly reported in the literature is the relationship between PLP and residual limb pain (Ahmed et al., 2017). Aspects of the residual limb can influence PLP, including fluid retention in the limb and application of pressure to, or removal of pressure from, the limb (Giummarra et al., 2011). The influence of prosthesis use on PLP has also been frequently reported, including the amount of prosthesis use, an improperly fitting prosthesis, or removal of the prosthesis (Giummarra et al., 2011). In addition, some studies have reported ways in which PLP can be affected by preamputation pain, including lifestyle factors (e.g., sleep), demographic characteristics (e.g., age), and other comorbid conditions (e.g., back pain; Ahmed et al., 2017; Ephraim et al., 2005; Giummarra et al., 2011; Münger et al., 2020). Veterans exhibit higher rates of serious health conditions (e.g., diabetes, cancer) than civilians, and thus they require a particular focus on the interaction of these conditions with pain (Eibner et al., 2015).

Various psychological factors, including depression, anxiety, stress, and pain catastrophizing, have been suggested to influence PLP (Ahmed et al., 2017; Giummarra et al., 2011; Vase et al., 2012). In Veterans, depression, anxiety, posttraumatic stress disorder, and other mental health concerns often co-occur, creating additional clinical complexity (Knowles et al., 2019). Coping strategies can affect PLP, and Veterans often use coping strategies that are influenced by military conditioning, including “getting on with it” despite pain, perceiving pain as a form of weakness, and self-reliance for pain management and control (Hitch et al., 2020). Nonpainful factors related to perception of the phantom limb, including intensity of nonpainful phantom limb sensation (e.g., itching) and an individual’s ability to voluntarily move their phantom limb, may affect PLP as well (Kikkert et al., 2017; Münger et al., 2020).

Social factors associated with PLP include lack of employment after amputation, which is concerning given that Veterans with amputation have a more difficult time securing and maintaining employment (Hawley et al., 2022). A lack of social support (e.g., interactions with family, friends, others with amputation, health care providers) can also influence PLP (Gallagher et al., 2001). For Veterans, adapting to amputation often includes withdrawing from military service and transitioning to civilian life, a move that increases the importance of connecting with peers who have been through similar experiences (Murray et al., 2024). This support, which can take the form of education, advice, and comfort throughout the experience, can be beneficial both before and after amputation.

The physical environment also influences PLP; however, environmental factors are difficult to classify in the biopsychosocial model because of the environment’s interaction with biological, psychological, and social factors (Stineman & Streim, 2010). Environmental factors that may contribute to PLP include the weather (e.g., temperature) and time of day (e.g., night; Giummarra et al., 2011; Wilkins et al., 2004). Overall, the many factors associated with PLP demonstrate its complexity and support in the form of a model that can be used for categorization and understanding.

Challenges in Applying the Biopsychosocial Model to Occupational Therapy Care

Although the biopsychosocial model provides a useful context for categorizing the various factors (Figure 2), overlap does exist, and factors may fall into two or more categories (e.g., sleep disturbance could be biological and psychological). During clinical appointments, Veterans often report more than just one factor that they believe might contribute to their PLP episodes, demonstrating a combined effect of biological, psychological, and social factors on their pain. Moreover, factors can be correlated or influence one another (Miaskowski et al., 2020). For example, lack of social support (a social factor) may lead to depression (a psychological factor). These challenges make it unclear which factors should be the focus of treatment, or which intervention strategies might be most effective in reducing PLP for a particular Veteran.

Figure 2.

Biological, psychological, and social factors that can be associated with phantom limb pain after amputation.

Another challenge in applying the biopsychosocial model is the siloed nature of health care disciplines for amputation and Veteran care. Pain management often requires input from multiple clinicians, but coordinating care across specialties can be difficult (Miller et al., 2021). Some Veterans have stated that there can be a lack of communication and collaboration between departments, potentially leading to delays in care or additional, unnecessary appointments (Kintzle et al., 2024). An improved biopsychosocial approach to PLP management requires increased collaboration through interdisciplinary care and the use of clinical strategies (e.g., participation in team rounds, clear documentation, relationship-building).

Recommendations for PLP Assessment and Treatment

Recommendations describing the assessment of patients’ pain have previously been published (American Occupational Therapy Association, 2021). To build on pain assessment, occupational therapy practitioners must also aim to determine the dominant category of factors (i.e., biological, psychological, or social) that are contributing to pain for a Veteran so they can prioritize treatment focus. Evaluations should include patient interviews, standardized outcome measures, and goal-setting (see the Supplemental Material, available online with this column at https://research.aota.org/ajot).

Occupational therapy practitioners must also consider each patient’s uniqueness; although multiple Veterans may report similar PLP (Figure 3), further evaluation may reveal variations in the dominant category of the biopsychosocial model and therefore different treatment needs. For example, Veteran 1 may benefit from cognitive–behavioral therapy to address depression (Pereira et al., 2023), Veteran 2 may be referred to their prosthetist for prosthetic socket modifications to improve fit (Pascale & Potter, 2014), and for Veteran 3 a therapist may recommend joining a peer support group to connect with other individuals with amputation to facilitate social skill building and community reintegration (Asano et al., 2008). Targeted treatments like these to address associated factors have been shown to reduce pain intensity and interference (Murphy et al., 2022). However, to recommend appropriate treatment strategies, it is imperative that therapists first evaluate each unique Veteran using this biopsychosocial approach.

Figure 3.

Three separate Veterans may present similarly with phantom limb pain after amputation.

It is important to note that the biopsychosocial model of pain factors for each Veteran is dynamic; the presentation of various factors may shift over time. A Veteran evaluated today may reveal primarily biological contributors to PLP, but in 6 mo that same Veteran’s contributors may shift to primarily psychological ones (Figure 4). These shifts can result from changes in lifestyle, treatment effects, or other unknown reasons. Similar to other complex chronic pain conditions, use of the biopsychosocial model for long-term management of PLP can be beneficial for ongoing assessment and treatment (Cheatle, 2016). Continuing the Veteran–therapist communication about PLP, regularly assessing biopsychosocial factors, and monitoring treatment effectiveness are important aspects of quality care for Veterans with amputation.

Figure 4.

Factors that contribute to phantom limb pain may shift over time for a Veteran.

Action Steps for Occupational Therapy

Occupational therapy practitioners are uniquely positioned on interdisciplinary care teams to aid in PLP management because of their focus on helping patients engage in meaningful occupations, which can reduce pain (Fisher et al., 2007). In the Veterans Health Administration, Veterans with amputation typically have annual wellness checks with their amputation team; these often involve a physiatrist, prosthetist, and physical therapist. These annual visits would benefit from the involvement of an occupational therapist, who could provide an opportunity for repeated reassessments to monitor changes in PLP, associated factors, and function over time to maintain lifelong rehabilitation. Including these rehabilitation perspectives in annual care can be beneficial for improving function, minimizing the risk of complications, and facilitating participation (Mills et al., 2017). Throughout postamputation rehabilitation (i.e., from inpatient to outpatient care), occupational therapists must advocate for Veterans by providing valuable information from their evaluation to the rehabilitation team, such as the Veteran’s ability to perform daily activities. Occupational therapy practitioners’ focus on patient function and participation brings unique strengths to interdisciplinary care, and their input can inform team decisions on rehabilitation stays, mobility devices, and other interventions.

Conclusion

Evaluating Veterans in the context of the biopsychosocial model can aid occupational therapists in interpreting pain factors and recommending appropriate treatments. Occupational therapy practitioners should play a larger role on postamputation rehabilitation care teams to aid Veterans in engaging in meaningful activities. Continued evaluation over time and ongoing Veteran–therapist conversations can reveal changes in PLP factors to inform new management strategies.