Combined effects of static stretching and electrical stimulation on joint range of motion and muscle strength
The purpose of this study was to examine the effects of the combination of static stretching (SS) and electrical stimulation (ES) for 8 weeks on joint range of motion (ROM), muscle strength, and muscle architecture. Thirty-one subjects were divided into three groups: the SS combined with ES (SS+ES) group, SS group, or control group. The SS+ES group performed calf stretching simultaneously with ES to the gastrocnemius medialis, while the SS group performed calf stretching only. The training regimen consisted of four 30 sec sets of stretching, with 30 sec rest intervals, 3 days per week for 8 weeks. The control group did not perform any intervention exercise. Before and after training, measurements were taken to determine the ankle ROM, plantar flexion one repetition maximum strength, muscle thickness, pennation angle, and circumference of the lower leg. The results showed that 8 weeks of training led to significant improvements in the ankle ROM and muscle thickness in both the SS+ES and SS groups. There were significant increases in plantar flexion one repetition maximum strength and pennation angle in all three groups. For all parameters, there was no difference between the SS+ES and SS groups. These results clarify that 8 weeks of SS improves joint ROM and muscle thickness, and show that there is no additional benefit gained by combining ES with SS in this particular training regime.