Eccentric loading for Achilles tendinopathy--strengthening or stretching?

Area of Science:

• Sports Medicine
• Rehabilitation Science
• Biomechanical Engineering

Background:

• Eccentric loading is a standard rehabilitation for chronic Achilles tendinopathy.
• These exercises are often termed strengthening programs.
• Current protocols may not optimize strengthening due to parameters and avoidance of natural eccentric-concentric coupling.

Purpose of the Study:

• To critically evaluate eccentric loading as an optimal strengthening program for Achilles tendinopathy.
• To propose an alternative interpretation of eccentric exercises in tendinopathy rehabilitation.
• To discuss the implications for future research and clinical practice.

Main Methods:

• Literature review and critical analysis of existing research on eccentric loading for Achilles tendinopathy.
• Examination of biomechanical principles related to eccentric-concentric coupling and the stretch-shortening cycle.
• Synthesis of arguments for and against eccentric loading as a primary strengthening intervention.

Main Results:

• Eccentric loading parameters often deviate from optimal strengthening protocols.
• The exercises may primarily act as a stretching stimulus for passive tissues rather than a true strengthening stimulus.
• The typical eccentric-concentric coupling of the stretch shortening cycle is often avoided.

Conclusions:

• Eccentric loading for Achilles tendinopathy may be better understood as a specific stretching protocol.
• This reinterpretation could guide future research into tendinopathy mechanisms.
• Adjunct sports-specific strengthening programs are likely crucial for optimal patient outcomes.