Achilles tendinopathy is a common overuse injury in football players and is associated with pain, stiffness, and reduced functional performance. Conservative treatment options such as eccentric calf muscle exercises and heel insole lifts are frequently used in rehabilitation; however, evidence comparing their effectiveness remains limited.

This randomized controlled trial compared the effects of eccentric calf muscle exercises and heel insole lifts on pain, ankle range of motion, and functional outcomes in male football players with Achilles tendinopathy. Participants were randomly assigned to one of two intervention groups. One group performed a structured eccentric calf muscle exercise program, while the other group used heel insole lifts during daily activities.

Outcomes related to pain intensity, functional ability, calf muscle performance, and ankle range of motion were assessed at baseline and after completion of a 12-week intervention period. The results of this study aim to support evidence-based rehabilitation strategies for the management of Achilles tendinopathy in football players.

This study was a single-blinded, randomized controlled trial conducted after obtaining ethical approval from the institutional ethics review committee. Male football players aged 18 to 30 years with clinically diagnosed Achilles tendinopathy were recruited from football clubs in Lahore, Pakistan, using a non-probability convenience sampling technique. Participants who met the eligibility criteria were randomly allocated into two parallel intervention groups using a lottery method.

Participants in the experimental group received an eccentric calf muscle exercise program based on Alfredson's protocol. The exercises were performed on a step with the knee extended and slightly flexed to target the gastrocnemius and soleus muscles, respectively. The protocol consisted of three sets of fifteen repetitions, performed twice daily, seven days per week, over a 12-week period. Body weight was used as resistance, and additional external load was progressively added as pain decreased.

Participants in the control group were provided with prefabricated heel insole lifts and instructed to wear them continuously in their regular footwear during daily activities throughout the 12-week intervention period.

Outcome measures were assessed at baseline and after completion of the intervention period. These included pain intensity, functional ability, calf muscle endurance, and ankle dorsiflexion range of motion. The study was conducted in accordance with ethical principles, and written informed consent was obtained from all participants prior to enrollment. The findings of this study are intended to contribute to evidence-based sports rehabilitation practices for the management of Achilles tendinopathy.

Inclusion Criteria:

• Male football players aged 18 to 30 years
• Clinical diagnosis of Achilles tendinopathy
• Achilles tendon pain for at least one month
• Pain intensity of 3 or higher on the Visual Analogue Scale
• Pain aggravated by weight-bearing activities
• Able to understand English and complete questionnaires
• Willing to avoid other treatments for Achilles tendinopathy during the 12-week study period

Exclusion Criteria:

• Lower limb injury within the past 6 months
• Previous Achilles tendon rupture or surgery
• Chronic ankle instability
• Recent use of eccentric exercises or heel insole lifts
• Metabolic or endocrine disorders
• Current use of medications other than paracetamol
• Unwillingness to comply with the study protocol

Individual participant data will not be shared because this study was conducted as an academic research project. The informed consent obtained from participants did not include provisions for public data sharing, and the dataset contains sensitive personal health information. Data will be stored securely and used only for academic and research purposes in accordance with institutional ethics approval.

Outcome assessors were blinded to group allocation to minimize assessment bias. Participants and care providers were not blinded due to the nature of the interventions.