The effect of surface neuromuscular electrical stimulation and compression hosiery applied to the lower limb, on the comfort and blood flow of healthy subjects

A randomised controlled trial of neuromuscular stimulation in non-operative venous disease improves clinical and symptomatic status

BACKGROUND

This randomised controlled trial investigates the dosing effect of neuromuscular electrical stimulation (NMES) in patients with chronic venous disease (CVD).

METHODS

Seventy-six patients with CEAP C3-C5 were randomised to Group A (no NMES), B (30 minutes of NMES daily) or C (60 minutes of NMES daily). Primary outcome was percentage change in Femoral Vein Time Averaged Mean Velocity (TAMV) at 6 weeks. Clinical severity scores, disease-specific and generic quality of life (QoL) were assessed.

RESULTS

Seventy-six patients were recruited - mean age 60.8 (SD14.4) and 47:29 male. Six patients lost to follow-up. Percentage change in TAMV (p<0.001) was significantly increased in Groups B and C. Aberdeen Varicose Veins Questionnaire Score (-6.9, p=0.029) and Venous Clinical Severity Score (-4, p-0.003) improved in Group C, and worsened in Group A (+1, p=0.025).

CONCLUSIONS

Daily NMES usage increases flow parameters, with twice daily usage improving QoL and clinical severity at 6 weeks in CVD patients.

Changes in the electrical properties of the electrode-skin-underlying tissue composite during a week-long programme of neuromuscular electrical stimulation

Particular neuromuscular electrical stimulation (NMES) applications require the use of the same electrodes over a long duration (>1 day) without having access to them. Under such circumstance the quality of the electrode-skin contact cannot be assessed. We used the NMES signal itself to assess the quality of the electrode-skin contact and the electrical properties of the underlying tissues over a week. A 14% decrease in the skin's stratum corneum resistance (from 20 to 17 kΩ) and a 15% decrease in the resistance of the electrodes and underlying tissues (from 550 to 460 Ω) were observed in the 14 healthy subjects investigated. A follow-on investigation of the effect of exercise-induced sweating on the electrical properties of the electrode-skin-underlying tissue composite during NMES indicated a correlation between the decrease in the resistance values observed over the course of the week and the accumulation of sweat at the electrode-skin interface. The value of the capacitance representing the dielectric properties of the skin's stratum corneum increased after exercise-induced sweating but did not change significantly over the course of the week. We conclude that valuable information about the electrode-skin-underlying tissue composite can be gathered using the NMES signal itself, and suggest that this is a practical, safe and relatively simple method for monitoring these electrical properties during long-term stimulation.