4. Discussion
BLIND
The present investigation aimed to compare the effects of 6 weeks of eccentric-oriented vs. traditional strength training on return-to-sport outcomes in late-stage ACL rehabilitation in professional team sport athletes. The study results showed that, although both training programs significantly improved all tested parameters, the eccentric-oriented training program resulted in significantly greater improvements concerning lower body strength, vertical jump performance, single-leg jump with injured leg (SLJI), single-leg hop with injured leg (SLHI), and triple-leg hop with injured leg (TLHI) performance. No significant training-effect differences were determined for isometric strength (limb symmetry index), single-leg jump test (uninjured leg), single-leg jump test (limb symmetry index), single-leg hop test (uninjured leg), single-leg hop test (limb symmetry index), triple-leg hop test (uninjured leg), and triple-leg hop test (limb symmetry index). Thus, eccentric-oriented training can be considered a worthy functional performance-improvement training method in professional team sports for late-stage ACL surgery patients. It is generally recognized that strength training is a cornerstone of every sound ACL rehabilitation program [In a 6-week study by Kasmi et al. [Several other articles addressed the effects of eccentric training on distinct return-to-sport performance outcomes in the non-professional athlete population. Lepley et al. [No significant training effect between eccentric and traditional training for limb symmetry indexes was found, with several possible explanations for the obtained results. As presented in Our study results showed greater efficacy of eccentric-oriented than traditional rehabilitation programs in injured leg performance, while no differences between training programs for uninjured leg performance were shown. Mechanisms that are likely responsible for the obtained results should be concisely hypothesized. First, continuing use of eccentric exercise is able to improve muscle morphology, with increases in fascicle length and cross-sectional area while targeting type II fibers being regularly established [A few study limitations are noteworthy. First, assessment of the hamstring strength/power parameters should be included in the return to sport test battery to allow more intergroup comparison. Second, due to the nature of the intervention, it was not possible to blind the strength and conditioning coach to group allocation. Third, the small sample size in each group limits the statistical power and precludes the generalizability of study findings. Notwithstanding these limitations, the effectiveness of eccentric-oriented training on leg strength and power-related performance outcomes in late-stage ACL-rehabilitation professional team sport players is supported by the present study findings.