Lower-Extremity Kinetic Chain Exercise Program for Achilles Tendinopathy

Overview

Achilles tendinopathy is a common condition that causes pain, stiffness, and reduced function of the Achilles tendon. It can affect both physically active individuals and the general adult population, often making everyday activities and exercise more difficult. Exercise therapy is widely used as the primary conservative treatment; however, rehabilitation programs that focus only on the Achilles tendon may not address movement impairments involving the entire lower extremity. This randomized controlled trial will evaluate a rehabilitation program based on the lower-extremity kinetic chain in adults with chronic mid-portion Achilles tendinopathy. Fifty participants will be randomly assigned to receive either a kinetic chain-based exercise program or a conventional rehabilitation program. Assessments will be completed before the intervention begins and again after it is finished. The study will measure postural stability using the Biodex Balance System, foot and ankle function using the Foot and Ankle Outcome Score (FAOS), pain intensity using the Visual Analog Scale (VAS), and ankle range of motion using a goniometer. The results will provide information on the effects of a rehabilitation approach that addresses the coordinated function of the lower extremity in people with chronic Achilles tendinopathy.

Background Achilles tendinopathy is one of the most common overuse conditions affecting the lower limb. It is characterized by activity-related pain, localized tenderness, reduced tendon function, and decreased tolerance to loading. These symptoms can limit daily activities, reduce participation in sports or exercise, and affect overall quality of life. Exercise-based rehabilitation is considered the primary conservative treatment for Achilles tendinopathy. Traditional rehabilitation programs mainly focus on strengthening the Achilles tendon and calf muscles. However, factors such as muscle weakness, impaired neuromuscular control, altered movement patterns, and reduced postural stability elsewhere in the lower extremity may also contribute to symptoms and functional limitations. The lower-extremity kinetic chain refers to the coordinated interaction of the foot, ankle, knee, hip, pelvis, muscles, fascia, ligaments, and other connective tissues during movement. Changes in the function of one part of this system may influence movement mechanics and loading across the Achilles tendon. A rehabilitation program that addresses the entire kinetic chain may therefore provide a broader approach to managing individuals with chronic Achilles tendinopathy. Objective The objective of this randomized controlled trial is to evaluate the effects of a lower-extremity kinetic chain-based exercise program on postural stability, pain intensity, ankle range of motion, and functional outcomes in patients with chronic Achilles tendinopathy. Study Design This prospective randomized controlled trial will include 50 adults diagnosed with chronic Achilles tendinopathy. Eligible participants will be randomly assigned to one of two groups: Experimental Group: Lower-extremity kinetic chain-based exercise program added to conventional rehabilitation program. Control Group: Conventional rehabilitation program only. Outcome assessments will be performed before the intervention and immediately after the intervention by an assessor who is blinded to group allocation. Outcome Measures The study will assess the following outcomes: Postural Stability: Overall Stability Index (OSI) will be measured using the Biodex Balance System. Foot and Ankle Function: Assessed using the Foot and Ankle Outcome Score (FAOS). Pain Intensity Level: Evaluated using the Visual Analog Scale (VAS). Ankle Range of Motion: Measured using a universal goniometer. Significance This study will examine a rehabilitation approach that combines exercises targeting the Achilles tendon with exercises designed to improve the coordinated function of the entire lower extremity. The findings will provide information about the effects of this intervention on balance, pain, ankle mobility, and functional performance in patients with chronic Achilles tendinopathy. The results may help inform future rehabilitation strategies and contribute to the evidence supporting exercise-based management of this condition.