Efficacy of Sensory Transcutaneous Electrical Nerve Stimulation on Perceived Pain and Gait Patterns in Individuals With Experimental Knee Pain

Abstract Objectives To examine the effect of experimental knee pain on perceived knee pain and gait patterns and to examine the efficacy of transcutaneous electrical nerve stimulation (TENS) on perceived knee pain and pain-induced knee gait mechanics. Design Crossover trial. Setting Biomechanics laboratory. Participants Recreationally active, individuals without musculoskeletal pain aged 18 to 35 years (N=30). Interventions Thirty able-bodied individuals were assigned to either a TENS (n=15) or a placebo (n=15) group. All participants completed 3 experimental sessions in a counterbalanced order separated by 2 days: (1) hypertonic saline infusion (5% NaCl); (2) isotonic saline infusion (0.9% NaCl); and (3) control. Each group received sensory electrical stimulation or placebo treatment for 20 minutes, respectively. Main Outcome Measures Perceived pain was collected every 2 minutes using a 10-cm visual analog scale (VAS) for 50 minutes and analyzed using a mixed model analysis of covariance with repeated measures. Gait analyses were performed at baseline, infusion, and treatment. Sagittal and frontal knee angles and internal net joint torque across the entire stance were analyzed using a functional data analysis approach. Results Hypertonic saline infusion increased perceived pain (4/10cm on a VAS; P