The standing heel-rise test for ankle plantar flexion: criterion for normal

Area of Science:

• Biomechanics and Musculoskeletal Assessment
• Kinesiology and Exercise Physiology

Background:

• Manual muscle testing is a standard for assessing muscle strength.
• Ankle plantar flexors are difficult to test with traditional manual resistance methods.
• The standing heel-rise test, using body weight, is a common substitute for assessing plantar flexion strength.

Purpose of the Study:

• To determine the number of standing heel-rises individuals without known weakness can perform.
• To challenge the existing standard for plantar flexion strength assessment.
• To establish a more accurate criterion for normal plantar-flexor function.

Main Methods:

• Two hundred three subjects (122 male, 81 female, aged 20-59) participated.
• Subjects performed as many standing heel-rises as possible.
• Monitoring of alignment and ankle motion was conducted with specific stopping criteria.

Main Results:

• The average number of heel-rises was 27.9 (SD = 11.1).
• No significant differences were found between male and female subjects.
• The lower 99% confidence interval for repetitions was 25.

Conclusions:

• The current standard of 1-5 repetitions for normal plantar-flexion strength is insufficient.
• A recommendation is made to change the testing criterion to 25 repetitions for a 'Normal' grade.
• This revised standard better reflects the endurance capacity of ankle plantar flexors.