The aim is to assess performance characteristics in jumps and functionality in participants with patellar tendinopathy and compare changes with various tendinopathy treatments in the short and medium term. As a secondary objective, the study aims to verify the relationship between changes in knee functionality assessed by the VISA-P and jump capacity in the different treatment groups. A double-blinded randomized controlled trial. Recruitment was conducted at sport clubs, with 48 participants with patellar tendinopathy included in the study. Participants were randomized into groups: dry needling (DN), percutaneous electrolysis (PNE), and sham needling as the control group (CG), all combined with eccentric exercise (EE). Functionality and performance during jumps, including squat jump (SJ) and counter movement jump (CMJ), were assessed. Significant differences were found in functionality between the pre-test and post-test evaluations, as well as between the pre-test and follow-up evaluations, in all three groups (p < 0.001). The DN group experienced an improvement in eccentric power (p = 0.021). A moderate correlation was found between the pre-test and post-test changes in functionality and SJ maximum concentric force (r = 0.63, p < 0.01, CI: 0.1; 0.8), CMJ maximum concentric force (r = 0.52, p = 0.05, CI: −0.01; 0.8), and CMJ eccentric power in the DN group (r = 0.63, p = 0.01, CI: 0.1; 0.8). Eccentric exercise could be effective in improving functionality in patellar tendinopathy and DN could improve eccentric power in jumps performance. Moreover, the DN group experienced an increase in functionality that correlated with the improvements found in jump performance in eccentric power and concentric strength.