The Calf Raise App shows good concurrent validity compared with a linear encoder in measuring total concentric work

The linear encoder and the Calf Raise App have been shown to be valid for measurements of plantar flexor muscular endurance in the heel raise test when compared with gold standard equipment. However, the validity of the Calf Raise App has not yet been compared with a linear encoder, an instrument commonly used in clinical and research settings. The purpose of this study was to determine the concurrent validity of the Calf Raise App compared with a linear encoder for the measurement of average heel raise height and total concentric work in the heel raise test.