Acute Effects of Contract-Relax Stretching vs. TENS in Young Subjects With Anterior Knee Pain: A Randomized Controlled Trial.

Valenza, MC, Torres-Sánchez, I, Cabrera-Martos, I, Valenza-Demet, G, and Cano-Cappellacci, M. Acute effects of contract-relax stretching vs. TENS in young subjects with anterior knee pain: A randomized controlled trial. J Strength Cond Res 30(8): 2271-2278, 2016-The aim of this study was to examine the immediate effects on pressure point tenderness, range of motion (ROM), and vertical jump (VJ) of contract-relax stretching vs. transcutaneous electrical nerve stimulation (TENS) therapy in individuals with anterior knee pain (AKP). Eighty-four subjects with AKP were randomly assigned to 1 of 3 different intervention groups: a contract-relax stretching group (n = 28), a TENS intervention group (n = 28), and a control group (n = 28). The participants included in the sample were both sex (37.5% men vs. 62.5% women) at a mean age of 21 years, with mean values of height and weight of 169 cm and 64 kg, respectively. The main outcome measures were knee ROM, pressure pain threshold (PPT), and VJ. The participants were assessed at baseline and immediately after treatment. In the case of VJ, at baseline, immediately after the intervention, at 3 and at 6 minutes posttreatment. The data analysis showed that PPT scores of participants in the stretching and TENS group significantly increased from pretest to posttest (p ≤ 0.05). A significant increase pre- to posttreatment in ROM (p < 0.001) was also observed in both treatment groups. In VJ measures, TENS and stretching groups showed significant differences between preintervention and all postintervention values (p ≤ 0.05), whereas no significant differences were found in the control group. In conclusion, the results show significant pre-to-post-treatment effects in PPT, ROM, and VJ from both contract-relax stretching and TENS in young subjects with AKP.