Normative values for calf muscle strength-endurance in the general population assessed with the Calf Raise Application: A large international cross-sectional study.

The sample was relatively young and active: mean age was 36 years, and 88% participated in sports, so these values may not apply to older or less active patients. The study had to reduce the planned sample to 500 because of pandemic restrictions, and 5 participants had technical recording errors; the normative table analysed 483 participants. Normative values are specific to the Calf Raise Application, a sticker below the lateral malleolus, a 10° incline, barefoot testing and a 60 beats-per-minute metronome; they may not transfer to flat-surface testing, shoes, different cadence or other devices. Primary outcomes were changed after registration: total work and vertical displacement were reclassified as primary, and repetitions and peak height were added as primary. Motivation and self-confidence were not measured, although they may affect maximal performance.

One author developed the free Calf Raise Application used to collect the data. The paper says the data came from researchers independent of the application's development.

Do not treat 25 repetitions as a universal normal result. The 95% reference interval was 13 to 50 repetitions, and performance was associated with sex, height, BMI and activity level. Also, these values apply only when the test is done with the Calf Raise Application on a 10° incline, barefoot and to a 60 beats-per-minute metronome.