Oct 14, 2019

Does Laser Fit into an Evidence-Based Approach to Treating Plantar Fasciitis?


Mark Callanen, PT, DPT, OCS

{Sponsored} 10-15% of all foot or ankle pain complaints are due to plantar fasciitis (PF)¹. Etiology for PF varies, however, it is a condition that is normally associated with a biomechanical dysfunction that places excessive stress on the soft tissues of the plantar surface of the foot. Mechanical overload can be exacerbated by factors such as over pronation, obesity, over training, restricted dorsiflexion ROM, and atrophy of intrinsic muscles at the foot.²

PF normally presents with pain located over the plantar surface of the foot, specifically at the medial aspect of distal calcaneus where the plantar aponeurosis attaches. It is usually reproducible with palpation. Subjective pain can be described as burning, throbbing, and/ or piercing, especially with weight bearing during the initial morning steps. Pain can persist from months to years.²

Objective findings include: positive Windless Test, negative Tarsal Tunnel Test, abnormal Foot Posture Index Score, and high Body Mass Index.² Image testing to confirm PF diagnosis can include ultrasound and MRI.^3,4 PF normally presents with fascial tissue that has a thickness of >4 mm on ultrasound and is hypoechonic with MRI testing.^3,4 A variety of functional tests can be used to quantify functional deficits including the Foot and Ankle Ability Measure (FAAM), Foot Health Status Questionnaire (FHSQ), or the Foot Function Index (FFI) to name a few.²

While acute cases may involve inflammation, recent studies emphasize that it is more of a degenerative process.^4-6 This should guide treatment decisions to focus on normalizing the stresses being placed on the foot as well as addressing the degenerative nature of the tissue involved at the heel. Using modalities that solely focus on decreasing inflammation are not ideal in treating PF.²

The JOSPT practice guideline on Heel Pain—Plantar Fasciitis: Revision 2014 recommends the following physical agents to help reduce pain and improve function:

Recommended

• LLLT (Low Level Laser Therapy), now referred to as photobiomodulation (PBM)
• Phonophoresis
• Iontophoresis

Not recommended

• General electrical stimulation
• Dry Needling
• Ultrasound

Also recommended for a PF plan of care: manual therapy, stretching, taping, foot orthoses, night splints, rocker bottom shoes, strengthening and neuro reeducation of foot musculature.²

While it is not difficult to understand many of the recommendations made to reduce physical stresses on the foot, nor the anti-inflammatory use of phonophoresis and iontophoresis to address acute inflammation, the recommendation of PBM/laser therapy might not be as clear to all readers.

PBM has the ability to not only address inflammation and pain, but also can help promote tissue healing due to the following factors:

Increased cell proliferation

Increased microcirculation

Vascular neoformation

Increased collagen production via increased fibroblastic activity⁹

With regard to pain and inflammation, PBM has the ability to inhibit and/or attenuate the expression of several inflammatory mediators and pain markers.⁷ It is important to understand the differences between helping the body reduce swelling naturally via PBM vs. blocking the inflammatory cascades with medication when it comes to muscle repair in the foot.

While NSAIDs decrease swelling, they have been shown to negatively impact tissue repair by diminishing proliferation, differentiation, and fusion of satellite cells in muscle tissue.⁸ This can promote intrinsic muscle atrophy via impaired skeletal muscle repair, growth, and increased fibrosis, all of which are components of chronic PF. For those clinicians advising the use of NSAIDS for PF, these factors should not be overlooked.

The most current research has further supported the use of laser on PF. A 2019 meta-analysis and systematic review on the Parameters and Effects of Photobiomodulation in Plantar Fasciitis concluded that photobiomodulation (PBM) is effective in treating pain and improving foot function in patients with chronic PF.⁹ A second meta-analysis paper regarding laser and PF was published in Medicine in December 2018 and had similar findings. The researchers concluded that LLLT relieves heel pain with lasting effects for 3 months after treatment.¹⁰

Given that PBM can help with pain and inflammation during the initial healing process but can also help promote stronger, healthier scar tissue, it is a modality that is well positioned to help both acute and chronic PF cases. It is not surprising that therapy lasers are being increasingly used in rehabilitation clinics and athletic treatment spaces to complement PF plans of care.

For more information about the benefits of laser therapy, visit www.lightforcetherapylasers.com

References

1. Rompe JD, Furia J, Weil L, Maffulli N. Shock wave therapy for chronic plantar fasciopathy. Br Med Bull 81:183–208, 2007.
2. MARTIN, RL, et al. Heel Pain—Plantar Fasciitis: Revision 2014 Clinical Practice Guidelines Linked to the International Classification of Functioning, Disability and Health from the Orthopaedic Section of the American Physical Therapy Association. J Orthop Sports Phys Ther. 2014;44(11):A1-A23.
3. Akfirat M, Sen C, Günes T (2003) Ultrasonographic appearance of the plantar fasciitis. Clin Imaging 27:353–35.
4. Berkowitz JF, Kier R, Rudicel S (1991) Plantar fasciitis: MR imaging. Radiology 179:665–66.
5. Schwartz EN, Su J. Plantar fasciitis: a concise review. Perm J 18:105, 2014.
6. Tu P, Bytomski JR. Diagnosis of heel pain. Am Fam Physician 84:909–916, 2011. Thomas JL, Christensen JC, Kravitz SR, Mendicino RW, Schuberth JM, Vanore JV, Weil LS Sr, Zlotoff HJ, Bouche R, Baker J; American College of Foot and Ankle Surgeons Heel Pain Committee. The diagnosis and treatment of heel pain: a clinical practice guidelines revision 2010. J Foot Ankle Surg 49:1–19, 2010.
7. Macias DM, Coughlin MJ, Zang K, et al. Low-level laser therapy at 635 nm for treatment of chronic plantar fasciitis: a placebo-controlled, randomized study. J Foot Ankle Surg 2015;54:768–772.
8. Duchesne E, Dufresne S, Dumont N. Impact of Inflammation and Anti-inflammatory Modalities on Skeletal Muscle Healing: From Fundamental Research to the Clinic. Physical Therapy [serial online]. August 2017;97(8):807-817.
9. Dos Santos et al. Parameters and Effects of Photobiomodulation in Plantar Fasciitis: A Meta-Analysis and Systematic Review. Photobiomodulation, Photomedicine, and Laser Surgery. Volume XX, Number XX, 2019, © Mary Ann Liebert, Inc. Pp. 1–9.
10. Wang et al. Clinical efficacy of low-level laser therapy in plantar fasciitis: A systematic review and meta-analysis. Medicine (2019) 98:3.