photo caption: Virtual Embodiment Training technology applies Graded Motor Imagery, Cognitive Behavioral Therapy, corrective exercises from physical therapy that focus on performing activities of daily living, and real-time position tracking to retrain the brain to perceive movement as non-threatening. This technology is designed for use in a variety of chronic pain applications, including low back pain, shoulder pain, neck pain, and postsurgical pain, among others.

By Jim Scherer, PT, DPT, OCS, Cert MDT, Movement Science Fellow

The purpose of this article is to discuss new techniques in the management of chronic pain. Here, the patient outcomes using traditional treatments are compared to those using emerging technology and techniques. Passive modalities, core stabilization, Graded Motor Imagery (GMI), Virtual Embodiment Training, and Cognitive Functional Therapy (CFT) will be considered in this context.

To begin, let’s reframe this away from chronic pain management and toward treatment of persistent pain. “Chronic” implies that the patient will have to live with a painful condition for the rest of her/his life, while “persistent,” on the other hand, implies the condition has lasted for a prolonged period of time. We should also consider the definition of pain. The International Association for the Study of Pain (IASPA) defines pain as “An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.” Pain represents both a tactile sensation and an emotional experience. It can occur with or without actual tissue damage. Interestingly, there is a weaker than expected correlation between the amount of tissue damage sustained and the pain level an individual experiences.1

Treatment of persistent pain is considered successful when there is a reduction in pain, a return to work, an increase in function, or an increase in quality of life. Thus, treatment can even be successful without pain reduction. Quality of life is not well correlated with pain level and better correlated with beliefs about pain.2 While it’s easier in practice to achieve temporary reductions in pain within a session, it’s much harder to make reductions in pain that persist for months or years. If we can’t get a permanent reduction in pain, the goal is often to increase a patient’s quality of life and functional capacity.

The most common treatments for persistent pain are passive modalities. Examples of passive modalities include ultrasound, electrical stimulation, low-level laser, hot and cold packs, soft tissue massage, and joint mobilization. According to several meta-analyses, ultrasound therapy is ineffective,3 and low-level laser treatment has mixed results and its efficacy is inconclusive.4,5

Electrical stimulation, hot and cold packs, and massage all provide temporary reductions in persistent pain after treatment. There is also strong evidence that high-intensity electrical stimulation for knee and shoulder surgeries in the acute phase increases strength and musical activation. Spinal manipulation therapy (SMT) is the most efficacious of all of these passive modalities and has the best outcomes when combined with exercise.6

All of these passive modalities limit patient self-efficacy. While these can be used sparingly in persistent pain treatment, eventually patients should be weaned off and encouraged to use more active coping strategies.

Several studies show that self-efficacy decreases disability level and improves outcomes for chronic headaches, chronic back pain, rheumatoid arthritis, fibromyalgia, chronic fatigue syndrome, osteoarthritis, and many more persistent pain conditions.7-10

Pain Relief Technologies

The conversation now shifts to discussion about new technologies that can assist in the treatment of persistent pain. Complex Regional Pain Syndrome (CRPS) is a particularly challenging type of persistent pain to treat. Patients with this condition can be so sensitive that air conditioning or the weight of sheets or clothing can irritate them for hours. How can we progress individuals with such sensitive nervous systems or crippling fear of movement? Two approaches to treat highly sensitive individuals are GMI and Virtual Embodiment Training, which are best done with patients that are fairly disabled and/or patients that have not responded well to traditional exercise programs.

The goal of these methodologies and technologies is to disassociate the neurons that are firing together and represent our experience of pain from the areas of the brain planning movement. These neurons tend to wire together after an individual has been in persistent pain, meaning that thinking about or seeing movement can cause pain without stimulus to the body.

Graded Motor Imagery Effectiveness

GMI is a three-step process. The classic clinical research has patients performing GMI exercises for 30 to 60 minutes, which can be split up into smaller sessions performed multiple times per day. CRPS patients commonly experience an aversion to looking at or imagining the affected body part moving, sometimes wanting to amputate the limb.11

For maximum effectiveness, it’s essential to get patient buy-in, explain the science behind the treatment, and have an understanding that it may take several sessions before compliance in the home occurs. GMI, in particular, was found to be less effective with inadequate practice.12

The three steps of GMI, in order, are Laterality, Explicit Motor Imagery, and Mirror Therapy. There is evidence that performing these sequentially is important for maximum progress. Laterality includes having the patient look at photos of left and right body parts including hands, feet, knees, etc, and identifying which side of the body they’re viewing. Laterality for the neck and back is completed by identifying which way the neck or back is turned or tilted. This can be done by looking at a magazine, a set of pictures or—my favorite—a cell phone app, which can track the patient’s compliance and results.

After 2 weeks, the individual then starts explicit motor imagery, imagining using the body part from a first-person perspective. Explicit motor imagery can be started by asking the person to imagine the body part as healthy, strong, and symmetrical, while threatening activities are progressively added. Mirror therapy, the final phase, is performed while watching the mirror image of the non-painful extremity move. There are multiple meta analyses demonstrating GMI is more effective than standard physical therapy at reducing pain in CRPS, phantom limb pain, and stroke.13,14,15

Virtual Embodiment Training Improves Movement

Virtual Embodiment Training is based on many of the same principles of Graded Motor Imagery, and its applications complement one another. As VR systems continue to become more affordable and accessible, it will become easier for patients to perform Virtual Embodiment Training via VR in the comfort of their own homes. VR technology is used for 30 to 45 minutes at a time to perform physical therapy exercises, constituting only part of the therapy session. The benefit of using VR comes from the patient feeling as though the virtual body they’re seeing is their own.16

This phenomenon is known as Virtual Embodiment, and when it occurs with individuals with persistent pain it can reduce their symptoms.17

This effect can be very strong and immediate: one study showed individuals with various persistent pain conditions experienced an immediate 60% reduction in pain while moving the affected limb while using a VR headset; a third had a complete reduction.18

Distraction is another proposed mechanism of action for pain relief with VR for many individuals with persistent pain.19 However, a recent study demonstrated that mirror visual feedback in VR can have influences on a nonaffected limb if movements of a nonaffected limb are mirrored to give the perception that a painful limb is moving.20

Trujillo et al used mirror visual feedback in VR to assess pain-free range of motion in unilateral chronic shoulder pain patients. Mirror visual feedback in VR is powerful because patients can move one arm in VR but visualize the opposite side moving. Trujillo et al measured shoulder range of motion in three planes (flexion, scaption, and abduction). When movements of the nonaffected limb were mirrored to the side experiencing chronic pain, patients demonstrated a decrease in range of motion of the nonaffected limb.

This suggests a learned association between movement and pain as well as the power of VR to provide deep contextual multimodal perception of movement. This further suggests that the mechanism by which VR alleviates pain may extend beyond just distraction therapy.

VR is a natural analgesic. Human beings are visual creatures, and the visual system often dominates over the other senses. Currently, VR software uses the pain relief of VR as a setting to engage in therapeutic exercises designed to increase range of motion. Many of these exercises also leverage visual distortions that are physically impossible in real life, helping to decrease the fear of movement (kinesiophobia).

Benefits of Exercise and Cognitive Function Therapy

Exercise is another excellent active coping strategy for persistent pain. It is likely that for patients with persistent back pain a well-rounded exercise program of any type will help to improve energy levels while relieving pain.21 Core stabilization is popular in the rehab and fitness industry, as it has been found to be superior to general exercise for the first 3 months but not at 6 months or 1 year.22-25

Spine instability and core stabilization started with an article about the activation of the abdominal muscles in individuals with low back pain by Paul Hodges and Richardson in 1997.26 Psychosocial factors are also underrepresented in the core stability model. Researchers have discovered that individuals with low back pain had increased stiffness and less movement, leading to less ability to absorb shock than those without back pain.27

These two studies are good arguments against core stabilization/bracing or guarding the low back when doing most daily activities. Exercise and an active lifestyle should be encouraged as an active coping strategy for individuals with persistent pain.

Cognitive Behavioral Therapy

A newer treatment for persistent low back pain that is growing and evolving is CFT, which is different from cognitive behavioral therapy (CBT). However, research is growing for physical therapists effectively delivering CBT.28

Typically this is done in combination with therapeutic exercise and/or neuromuscular re-education. CBT is performed by a physical therapist in conjunction with exercise, while CFT examines the integration of psychology and its effect on altering the movement system through guarding responses and vice-versa. CFT exercises are performed with verbal cuing to reinforce the concept that the back is inherently an adaptable structure and to take the attentional focus off the back. CFT will also include discussion with therapists that helps patients make sense of their pain with factors including stress management, overall activity level, maladaptive pain behaviors, sleep, and others.29

When compared to a control group treated with manual therapy and exercise (physical therapists selected the exercise), it was found that CFT significantly reduced disability, depression, anxiety, and improved quality of life at 3 months, 1 year, and 3 year follow-ups.29,30

Sixty percent of the patients in the experimental group reported a back-pain history of greater than 5 years, while pain significantly decreased in the CFT group at 3 months and 1 year, but not 3 years.

Help Patients Find a Better Way

There are many evolving treatment classification systems for low back pain for clinicians including multiple systems. Some of these include APTA Clinical Practice Guidelines for low back pain, Movement System Impairments, treatment-based classification systems, the McKenzie method, and Keele STarT Back. Many of these treatments are better equipped for the treatment of subacute and acute pain back pain then the CFT model and will continue to evolve. Other emerging treatments for persistent pain not discussed, but worth mentioning, include dorsal root ganglion stimulators, Pain Neuroscience Education, ketamine infusions, tactile discrimination, pain exposure, acceptance commitment therapy, cognitive behavioral therapy and motivational interviewing. Encouraging lifestyle changes, giving patients control of their rehabilitation by encouraging self-efficacy and exercises, examining central sensitization of the nervous system, and co-treating psychosocial factors are common threads in new treatments for persistent pain. PTP

Jim Scherer, PT, DPT, OCS, Cert MDT, Movement Science Fellow, graduated with his Doctorate of Physical Therapy from Ohio University in 2008. He received his Bachelor of Science in Exercise Physiology and Minor in Psychology. He became a McKenzie Certified practitioner in 2010, a Board Certified Specialist in Orthopedics in 2010, completed a Fellowship in Movement Science through Washington University in St. Louis in 2013-2014, and the Primary Spine Practitioner program through the University of Pittsburgh in 2017-2018. Scherer also does mentoring for USC’s Orthopedic residency program and has been involved a multidisciplinary chronic pain program for the past 6 years, specializing in CRPS (Complex Regional Pain Syndrome). For more information, contact PTPEditor@medqor.com.

References

  1. Butler DS, Moseley GL. (2013). Explain Pain: (Revised and Updated, 2nd Edition): Doctorzed Publishing.
  2. Lamé IE, Peters ML, Vlaeyen JW, Kleef Mv, Patijn J. Quality of life in chronic pain is more associated with beliefs about pain, than with pain intensity. Eur J Pain. 2005;9(1):15-24.
  3. Robertson VJ, Baker KG. A review of therapeutic ultrasound: effectiveness studies. Phys Ther. 2001;81(7):1339-1350.
  4. Chow RT, Johnson MI, Lopes-Martins RA, Bjordal JM. Efficacy of low-level laser therapy in the management of neck pain: a systematic review and meta-analysis of randomised placebo or active-treatment controlled trials. The Lancet. 2009;374(9705):1897-1908.
  5. Kadhim-Saleh A, Maganti H, Ghert M, Singh S, Farrokhyar F. Is low-level laser therapy in relieving neck pain effective? Systematic review and meta-analysis. Rheumatol Int. 2013;33(10):2493-2501.
  6. Rubinstein SM, de Zoete A, van Middelkoop M, Assendelft WJJ, de Boer MR, van Tulder MW. Benefits and harms of spinal manipulative therapy for the treatment of chronic low back pain: systematic review and meta-analysis of randomised controlled trials. BMJ. 2019; 364, l689. doi:10.1136/bmj.l689.
  7. Benyon K, Hill S, Zadurian N, Mallen C. Coping strategies and self‐efficacy as predictors of outcome in osteoarthritis: a systematic review. Musculoskeletal Care. 2010;8(4):224-236.
  8. Kalapurakkel S, Carpino EA, Lebel A, Simons LE. “Pain Can’t Stop Me”: Examining Pain Self-Efficacy and Acceptance as Resilience Processes Among Youth With Chronic Headache. J Pediatr Psychol. 2015;40(9):926-933. doi: https://www.doi.org/10.1093/jpepsy/jsu091.
  9. Lefebvre JC, Keefe FJ, Affleck G, et al. The relationship of arthritis self-efficacy to daily pain, daily mood, and daily pain coping in rheumatoid arthritis patients. Pain. 1999;80(1-2):425-435.
  10. Woby SR, Urmston M, Watson PJ. Self‐Efficacy mediates the relation between pain‐related fear and outcome in chronic low back pain patients. Eur J Pain. 2007;11(7):711-718.
  11. Lewis JS, Kersten P, McCabe CS, McPherson KM, Blake DR. Body perception disturbance: a contribution to pain in complex regional pain syndrome (CRPS). Pain. 2007;133(1-3):111-119.
  12. Johnson S, Hall J, Barnett S, et al. Using graded motor imagery for complex regional pain syndrome in clinical practice: failure to improve pain. Eur J Pain. 2012;16(4),:50-561.
  13. Bowering KJ, O’Connell NE, Tabor A, et al. The effects of graded motor imagery and its components on chronic pain: a systematic review and meta-analysis. J Pain. 2013;14(1):3-13.
  14. Moseley GL. Graded motor imagery for pathologic pain: a randomized controlled trial. Neurology. 2006;67(12):2129-2134.
  15. Polli A, Moseley GL, Gioia E, et al. Graded motor imagery for patients with stroke: a non-randomized controlled trial of a new approach. Eur J Phys Rehabil Med. 2017;53(1):14-23.
  16. Meijsing M. Real people and virtual bodies: How disembodied can embodiment be? Minds and Machines. 2006;16(4):443-461.
  17. Nierula B, Martini M, Matamala-Gomez M, Slater M, Sanchez-Vives MV. Seeing an embodied virtual hand is analgesic contingent on colocation. J Pain. 2017;18(6):645-655.
  18. Jones T, Moore T, Choo J. The impact of virtual reality on chronic pain. PloS One. 2016;11(12), e0167523. doi:10.1371/journal.pone.0167523.
  19. Malloy KM, Milling LS. The effectiveness of virtual reality distraction for pain reduction: a systematic review. Clin Psychol Rev. 2010;30(8):1011-1018.
  20. Trujillo M, Alvarez A, Crossland D, Petros J, Nguyen L. Virtual embodiment in virtual reality reveals mirror visual feedback influences on pain-free range of motion. Postgrad Med. 2019;31(S1):64-65.
  21. Gordon R, Bloxham S. A systematic review of the effects of exercise and physical activity on non-specific chronic low back pain. Healthcare (Basel, Switzerland). 2016;4(2):22. doi: https://www.doi.org/10.3390/healthcare4020022.
  22. Coulombe BJ, Games KE, Neil ER, Eberman LE. Core stability exercise versus general exercise for chronic low back pain. J Athl Train. 2017;52(1):71-72.
  23. Davin J, Callaghan M. BET 2: Core stability versus conventional exercise for treating non-specific low back pain. Emerg Med J. 2016;33(2):162-163. doi: https://www.doi.org/10.1136/emermed-2016-205681.2.
  24. Lederman E. The myth of core stability. J Bodyw Mov Ther. 2010;14(1):84-98.
  25. Wang XQ, Zheng JJ, Yu ZW, et al. A meta-analysis of core stability exercise versus general exercise for chronic low back pain. PloS One. 2012;7(12):e52082.
  26. Hodges PW, Richardson CA. Contraction of the abdominal muscles associated with movement of the lower limb. Phys Ther. 1997;77(2):132-142.
  27. Hodges P, van den Hoorn W, Dawson A, Cholewicki J. Changes in the mechanical properties of the trunk in low back pain may be associated with recurrence. J Biomech. 2009;42(1):61-66.
  28. Nielsen M, Keefe FJ, Bennell K, Jull GA. Physical therapist–delivered cognitive-behavioral therapy: a qualitative study of physical therapists’ perceptions and experiences. Phys Ther. 2014;94(2):197-209. doi: https://www.doi.org/10.2522/ptj.20130047.
  29. O’Sullivan PB, Caneiro JP, O’Keeffe M, et al. Cognitive functional therapy: an integrated behavioral approach for the targeted management of disabling low back pain. Phys Ther. 2018;98(5):408-423. doi: https://www.doi.org/10.1093/ptj/pzy022.
  30. Vibe Fersum K, O’Sullivan P, Skouen JS, Smith A, Kvåle A. Efficacy of classification-based cognitive functional therapy in patients with non-specific chronic low back pain: A randomized controlled trial. Eur J Pain. 2013;17(6):916-928. doi: https://www.doi.org/10.1002/j.1532-2149.2012.00252.x.