The purpose of this study was to investigate the immediate effects on pressure point tenderness, range of motion and vertical jump of contract-relax stretching versus transcutaneous electrical stimulation (TENS) therapy in people with anterior knee pain (AKP). Eighty-four subjects with AKP were placed at random into one of three 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 mean age of 21 years old, with mean values of height and weight of 169 cm and 64 kg. The main outcome measures were knee range of motion (ROM), pressure pain threshold (PPT) and vertical jump (VJ). The participants were assessed at baseline and immediately following treatment. In the case of VJ, at baseline, immediately after the intervention, at 3 and at 6 minutes post-treatment. The data analysis showed that PPT scores of participants in the stretching and TENS group significantly increased from pre-test to post-test (p<0.05). A significant increase pre to post treatment in ROM (p<0.001) was also observed in both treatment groups. In VJ measures, TENS and stretching groups showed significant differences between pre and all post-intervention values (p<0.05), while there were not any significant differences found in the control group.
The results from this study demonstrate significant pre-to-post-treatment effects in PPT, ROM and VJ from both contract-relax stretching and TENS in young subjects with AKP.