Measurement of the motion range in the loaded ankle

Area of Science:

• Biomechanics
• Orthopedics
• Sports Medicine

Background:

• Accurate measurement of ankle range of motion (ROM) is crucial for diagnosing conditions and guiding rehabilitation.
• Traditional methods often measure unloaded ankle ROM, which may not reflect functional capacity.
• Assessing loaded ankle ROM is essential for understanding joint mechanics during activities like walking and running.

Purpose of the Study:

• To present and validate an easily practicable method for measuring ankle range of motion under load.
• To compare the results of loaded ankle ROM measurements with traditional unloaded methods.
• To establish normative values for loaded ankle ROM in healthy individuals.

Main Methods:

• A novel method involving a patient standing on a 30-cm stool, leaning forward with the heel down (for dorsal extension) and heel raised (for plantar flexion).
• Measurements taken using a protractor to determine the angle between the foot's support line and the leg's long axis.
• Comparison with measurements from unloaded ankles in sitting or supine positions, and correlation with radiographic measurements of talar tilt.

Main Results:

• The loaded ankle ROM measurement method yielded greater and more reproducible values compared to unloaded measurements in a study of 317 healthy ankles.
• Mean loaded dorsal extension in 66 healthy ankles was 32.5 degrees, with a mean talar forward tilt of 5.0 degrees.
• Functional ROM requirements: at least 10 degrees for daily life, and 20-30 degrees for athletic activities.

Conclusions:

• The described method provides a reliable and practical approach to assess loaded ankle range of motion.
• Loaded ankle ROM measurements are superior to unloaded measurements for clinical and functional assessments.
• Understanding loaded ankle ROM is vital for optimizing athletic performance and preventing injuries.