Photobiomodulation Versus Sham for Management of Tibial and Metatarsal Stress Fractures; A Randomized Controlled Trial- APTA CSM 2026

d rhon, n parsons, r greenlee, e metzger, s hole, n hager

Abstract accepted for platform presentation at the 2026 American Physical Therapy Association Combined Sections Meeting

The purpose of this study was to compare the effectiveness of low-level laser therapy (photobiomodulation - PBMT) to sham on graduation rates in military trainees with lower extremity stress fractures. Based on prior reports about the influence of PBMT on bone repair, it was hypothesized that patients receiving PBMT would have significantly better outcomes than patients receiving sham.

Participants were trainees in the Combat Medical Specialist Training Course (CMSTC) in San Antonio, Texas, with an MRI-confirmed diagnosis of metatarsal and/or tibial stress fracture, enrolled between June 2023 and November 2024. All participants received standard of care treatment (activity modification, relative rest, a home exercise program, and physical therapy) and were then randomized to either active or sham PBMT. The PBMT protocol called for three sessions/week up to six weeks (10 to 16 minutes per treatment). Participants in the sham group were prescribed an identical number of sessions, with the device remaining in standby mode. The primary outcome was graduation without delay at four months, and secondary outcomes included the Defense and Veterans Pain Rating Scale (DVPRS) and the Lower Extremity Functional Scale (LEFS), also at four months. Patients with fractures to the 5th metatarsal, anterior tibia, a non-union fracture, pregnant, or with an open wound or tattoo over the area of treatment were excluded.

The mean age (SD) was 23.7 (4.7) years, 54.4% female, and 80.6% in the United States Army. In 46.6% of the cohort, both extremities were affected, with tibia involvement in 69.9% and metatarsal involvement in 30.1%, with severity ranging from grades I to IV. Distribution of severity was similar between groups, with slightly higher proportion of Grade III in the sham group (53.2% vs 30.6%) and slightly higher proportion of Grade II in the active PBMT group (49.0% vs 23.4%). Only 36.9% of all participants graduated without delays (20 from PBMT group; 18 from sham group). There was no statistically significant difference in graduation rates between groups. Furthermore, sex, laterality, and stress fracture location did not predict successful graduation rates. Pain (mean difference[9CI] DVPRS -0.7312 [-2.308, 0.8456]) and function (mean difference[95CI] LEFS 5.8101 [-8.0288, 19.649]) were also not different between groups at 4 months.

Graduation rates, pain intensity, and physical function at four months were not significantly different between military trainees that received low-level laser therapy compared to sham.