Hamstring injuries are common and recurrent in both elite and recreational athletes, often leading to prolonged absence from sports. The aim of this study is to compare the effects of eccentric and concentric exercise programs on the recovery of elite athletes diagnosed with grade II hamstring strain. Pain, flexibility, muscle strength, balance, and return-to-sport duration will be evaluated to determine the impact of different exercise modalities. Dynamic balance assessment will also be performed before and after treatment. The two intervention groups will be compared using the Wilcoxon test, with p<0.01 considered statistically significant. This study is expected to provide evidence on which exercise program is more effective in facilitating return to sport and to contribute to improved rehabilitation strategies in future athletic injuries.

amstring muscle strain is one of the most common injuries in elite sports, frequently leading to long rehabilitation periods and a high rate of recurrence. Although various treatment modalities have been studied, there is still no consensus on the most effective exercise approach for recovery and return to sport. This study investigates the effectiveness of two different rehabilitation strategies-eccentric exercise programs and concentric exercise programs-in elite athletes diagnosed with grade II hamstring strain.

The intervention will focus on structured exercise protocols applied over a defined treatment period. Outcomes to be assessed include pain intensity, hamstring flexibility, isometric and isotonic muscle strength, dynamic balance, and time to return to sport. Dynamic balance assessment is included as a novel parameter to better understand functional recovery after hamstring injury.

Statistical analysis will be performed using the Wilcoxon test for continuous variables, with p<0.01 considered significant. The results are expected to clarify which type of exercise program provides superior outcomes in terms of functional recovery and safe return to sport. This may help guide clinicians in designing more effective rehabilitation strategies for elite athletes and reduce the recurrence of hamstring injuries.

Inclusion Criteria:

• Participants over 18 ,who are elite athlete and contunie currently active sports life,and . Those with MRI findings showing hamstring grade II strain,who does not have any systemic or mental disease volunteerly participated in the study.

Exclusion Criteria:

• Participants who are having severe visual impairment and perception impairment, who has pain preventing to test,who has neurologic problems ans who has a history of injury for 6 months were excluded.

A decision regarding the sharing of individual participant data (IPD) has not yet been made. Considerations regarding participant privacy, confidentiality, and the sensitive nature of the data will inform any future decisions on data sharing.