Low-Level Laser Therapy for Plantar Fasciitis

Plantar fasciitis (PF), a degenerative injury of the connective tissue in the foot, results in pain-related disability in Service Members and contributes to decreased physical activity and excessive healthcare costs. Even if effective, current treatment protocols may require 6-12 months of therapy to return individuals to pain-free activity. Photobiomodulation therapy (PBMT) uses non-ionizing light to elicit biological changes in tissues resulting in beneficial therapeutic outcomes. Evidence supports use of PBM for other degenerative connective tissue conditions, such as achilles tendinopathy and epicondylitis. A previous pilot study was completed in an active-duty military and civilian population, which demonstrated a positive effect of two PBM dose parameters on function and pain levels in participants with chronic PF when combined with stretching and ice. These positive findings from the aforementioned study are promising in the treatment of this common and debilitating issue, but require the addition of a sham comparison to rigorously eliminate any potential placebo effect of the treatment protocol, and further refine the treatment protocol in order to make evidence-based clinical recommendations. As such, proposing a follow-up study and the addition of an objective outcome measure will strengthen the impact of the study.

SPECIFIC AIM 1: To assess the clinical effectiveness of photobiomodulation compared to sham photobiomodulation to improve function and decrease pain.

SPECIFIC AIM 2: To evaluate the effectiveness of photobiomodulation compared to sham photobiomodulation to resolve plantar fascial thickening. DESIGN: A prospective randomized sham-controlled trial to meet the aims of the study.

METHOD: A sample of up to 100 active-duty military members will be randomly assigned to the Sham-PBMT or PBMT group. At baseline, during the treatment protocol, and at long-term (3 and 6 months) follow-up, measures of foot function, pain, and plantar fascial thickness will be collected for analysis. The proposed methods will allow the study team to establish if PBMT is clinically effective to accelerate recovery compared to Sham-PBMT and result in resolution of fascial thickening, decrease in pain, and improved function.

LONG-TERM GOAL: The long-term goals of the research include developing PBMT protocols for broad application to other painful and duty-limiting conditions.

Recruitment, Pre-Screening (before consent), Study Introduction \& Informed Consent:

Potential participants will be identified via four methods:

1. Under the provisions of the Partial HIPAA Waiver, local study providers will review medical records of patients coming into the Orthopedic and Podiatry Clinics for suspected plantar fasciitis to identify prospective research participants for the purposes of seeking their authorization to participate/use their protected health information for this research study. In these cases, the study team will receive approval from the potential participant's provider prior to approaching for possible study participation.
2. Direct referral from local healthcare providers in the local Family Medicine, Podiatry, Physical Therapy, and Physical Medicine \& Rehabilitation (PM\&R) clinics.
3. Patients may self-refer to participate in the study. Interested potential participants will be able to contact a member of the study team via phone or email. Potential participants who contact the study team directly will be instructed to access the Physical Therapy clinic or their primary care manager for a physical exam and diagnosis of Plantar Fasciitis (PF) or confirmation of a previous PF diagnosis.
4. Study advertisements will be posted, and copies will be provided to clinic staff.

Eligibility will be determined in person. If the potential participant meets eligibility criteria as determined by the Inclusion/Exclusion CRF and expresses interest in participating, an authorized study team member will initiate the formal consent discussion and, if applicable, obtain informed consent.

Baseline Data Collection (post-consent): Prior to receiving the assigned study treatment, participants will provide their contact information and complete a series of baseline outcome measures (Demographics CRF and Baseline Data Collection CRF) and have their plantar fascia thickness measured within the Podiatry clinic. A study team member will also acquire measurements of the participant's calf, ankle, and foot to calculate the appropriate PBMT dose.

Randomization: Participants will be randomly assigned to a study group (PBMT+UC or Sham PBMT+UC) using a computer-generated randomization model prepared by the study biostatistician.

Study Treatments (PBMT+UC or Sham PBMT+UC): All participants, regardless of study arm assignment, will be asked to complete the UC Protocol, which consists of a daily regimen of stretching and cryotherapy that includes 3-5 minutes of stretching upon waking, then approximately 3-5 minutes of stretching and 3-5 minutes of cryotherapy throughout the day, for the duration of 6 weeks.

Participants will receive PBMT or sham-PBMT with the PBM device over the course of three consecutive weeks (three treatments per week). PBM treatments will take approximately 5-10 minutes to administer at each session. Specific treatment parameters will be based on measurements of calf, ankle, and foot using pre-calculated treatment tables; participants will receive 10 J/cm2, 25W output power, and the length of the treatment will be dependent on the treatment area (size).

Photobiomodulation Therapy (PBMT): PBMT will be administered by a trained member of the study team using the LightForce® XPi therapy laser, provided by LiteCure, LLC/DJO Global (New Castle, DE). The LightForce® XPi therapy laser is an FDA cleared device for the treatment of pain. The trained team members will use the Smart Hand Piece technology, which achieves effective treatments and improves dosing accuracy by assessing the operator's speed and providing real-time visual (red - amber - green light) and sensory feedback. The Smart Hand Piece is calibrated to shutoff when moving too slowly, and warn the operator when moving too fast by vibrating. The therapy is delivered through a flexible optical fiber threaded through the hand piece, which contains a rolling sapphire massage ball. The PBM therapy will be administered by rolling the massage ball over the plantar surface of the foot and dorsal aspect of the calf in contact with the participants' skin.

Sham-Photobiomodulation Therapy (Sham-PBMT): Sham-PBM treatment time will be calculated in the same way as the PBM treatment group, with the time of treatment dependent on the size of the treatment area. The sham-PBMT will be administered by rolling the massage ball over the plantar surface of the foot and dorsal aspect of the calf in contact with the participants' skin. Because emission of photons at the selected treatment parameters may cause participants in the treatment group to feel warmth, the massage ball will be warmed in the sham-PBMT. The device will be turned on, so the red aiming beam will be visible, but the operator will not activate the switch to emit photons. The following safeguards will be in place to prevent exposure to PBM and potential unexpected crossover or protocol deviations, as follows:

The PBM device requires multiple steps to emit photons. The device first must be powered on, then settings are selected (in this case, power will be 25 watts, and the time will be determined by the algorithm based on the treatment area measurements). Next, there is a 'standby' button that is activated on the touch screen, and finally, there is a finger switch on the handpiece that must be pressed to initiate the treatment. There is a beep that sounds for the duration of the active treatment.

For the sham condition, the device will be turned on and the settings will be selected, but the standby button and the finger switch on the handpiece will not be activated. This way, there is no chance that the device will be emitting photons. Since the device will not emit active treatment, there will not be a beeping sound from the device; this beeping noise will be replicated in another way for the sham-PBMT. At the completion of the initial 6 weeks, Sham-PBMT participants will be unblinded, and may choose to cross-over and complete another 6 weeks in the active treatment group. If Sham-PBMT participants choose to cross-over and receive active PBMT, participants will re-complete all of the original study procedures (with the exception of screening).

Follow Up Data Collection: In addition to their 3x weekly for 3 weeks PBM or Sham-PBM treatments, participants will report to the study team in person approximately 3 weeks (+/- 3 days) and 6 weeks (+/- 3 days) after the start of their PBM or Sham-PBM treatment to complete the follow-up questionnaires, turn in their Pain Diary, and undergo ultrasound imaging to measure changes in plantar fascia thickness at 3-weeks and 6-weeks.

Long-term follow up questionnaires will be captured remotely (e.g., entered directly into REDCap using a personalized coded link with no log-in required, verbally over the phone with a study team member, etc.) at approximately 3-months (+/- 10 days/weeks) post-start of PBM treatment. For Sham-PBMT participants who cross-over, their 3-month follow-up will be timed from the first day of their active PBM treatment, not their Sham-PBM treatment. Reminder phone calls and emails will be sent to participants at the phone and email address provided to the study team before the 3-month follow-up time point. Participants will be evaluated for adverse events at each follow-up time point and any complications will be documented.

Study participation ends after the 3-month follow-up research activities are completed. Participants initially randomized to the PBMT group will participate in the study for approximately 3 months. Participants initially assigned to the Sham-PBMT group who choose to cross-over and receive active PBMT post-unblinding will be in the study for approximately 4.5 months total.

Ultrasound Measurement: Plantar fascia thickness will be measured by an MSK US trained provider utilizing an ultrasound system. The participant will be identified on the ultrasound system using only the assigned participant ID. The patient will be positioned prone on an examination table with the leg extending off the end so the foot projects downward in a relaxed state. Using a linear transducer for best resolution, the plantar fascia will be evaluated in the long axis to determine the site to be measured as identified by the bony contour demonstrated. The vertical thickness of the plantar fascia will be documented in both long and short axis at this point. The points measured will be from the edge of the bone to the outer layer of the plantar fascia.

Plantar fascia thickness will be measured in two orthogonal planes (90 degrees different - long axis and short axis of the structure) at the site identified by the bone contour. The measurement will be conducted by MSK US trained providers, either in Physical Therapy or Physical Medicine and Rehab clinics.

Eligibility Criteria:
Inclusion Criteria:

* DEERS eligible
* Able to read and understand English language for consent purposes
* Experience pain in the bottom of foot and/or heel at any time during the day
* Diagnosis of Plantar Fasciitis (PF) by a healthcare provider based on accepted diagnostic criteria
* Abel to commit to study procedures, including a 6-week intervention and 3 month follow-up
* Have experienced symptoms of PF for at least 3 months

Exclusion Criteria:

* Diagnosed with a calcaneal (heel) fracture by a healthcare provider
* Currently pregnant or plan to become pregnant during intervention period (safety of PBM not established in pregnancy)
* History of traumatic injury to symptomatic foot/feet
* Previous surgery, or other invasive treatment for same condition
* Significant portion of calf area covered in tattoos/ink/scarring (pigment in ink can absorb light, causing overheating of skin)
* History of neuropathy or inability to detect changes in skin temperature (increased risk of skin warming due to inability to detect change)
* Current use of medications associated with sensitivity to heat or light (e.g., amiodarone, chlorpromazine, doxycycline, hydrochlorothiazide, nalidixic acid, naproxen, piroxicam, tetracycline, thioridazine, voriconazole)
* Concurrent participation in another research study addressing pain issue
* Current use of pacemaker
* Current or chronic sciatica resulting in chronic or intermittent lower extremity pain, numbness, or tingling
* Previous enrollment in this study for contralateral foot