Short-term effects of pulsed electromagnetic field therapy on subjective flexion-associated lameness responses and circulating cytokines in horses with distal tarsal osteoarthritis.

Overview

• This study examined the short-term effects of pulsed electromagnetic field (PEMF) therapy on pain-related lameness and inflammatory markers in horses suffering from distal tarsal osteoarthritis.

Background and Objective

• PEMF therapy is a treatment commonly used in equine sports medicine, believed to reduce inflammation and improve healing.
• Despite its widespread use, there is limited controlled research documenting the physiological impacts of PEMF therapy specifically in horses.
• The study aimed to determine whether PEMF influences lameness induced by joint flexion and the levels of circulating inflammatory cytokines in horses with radiographic signs of distal tarsal osteoarthritis.

Methods

• Six mares with radiographic evidence of distal tarsal osteoarthritis were involved in a repeated-measures crossover design, where each horse acted as its own control.
• Evaluations were conducted at four time points: baseline (sham PEMF), 1 hour, 1 day, and 1 week after a single PEMF treatment.
• The study used two approaches to assess lameness:
  • Subjective assessment by a blinded veterinarian following standardized tarsal flexion testing.
  • Objective gait analysis using an inertial sensor-based system called the Lameness Locator®.
• Serum cytokine levels were measured using a multiplex immunoassay to evaluate inflammatory responses.

Results

• Subjective lameness:
  • PEMF treatment significantly reduced flexion-induced lameness 1 hour post-treatment compared to baseline.
  • No significant reduction in lameness was observed at 1 day or 1 week post-treatment.
• Objective gait analysis:
  • No significant changes in gait asymmetry were detected at any post-treatment time point.
• Cytokine analysis:
  • Circulating interferon gamma (IFNγ) levels decreased significantly 1 hour after PEMF treatment, indicating a possible anti-inflammatory effect.
  • Other measured cytokines showed no significant changes post-treatment.

Conclusions

• PEMF therapy may provide temporary relief in subjective pain and reduce inflammatory signaling shortly after treatment in horses with distal tarsal osteoarthritis.
• The lack of changes in objective gait measurements suggests that the functional improvement may be subtle or short-lived.
• Overall, while PEMF showed some anti-inflammatory effects and reduced perceived pain, longer-term benefits or measurable improvements in gait require further investigation.