Evaluation of Leg-foot Range of Motion: Which Measurement Method Is Most Reliable?

Objective  To evaluate the methods of measuring leg-foot movement in normal ankles and feet by comparing the results of clinical measurements with those of radiographic measurement and to determine the range of leg-foot movement considered normal. Methods  Leg-foot movement was measured in 44 patients (60 feet) using a traditional goniometer, digital goniometer, inclinometer, smartphone application , in addition to radiographic measurement (considered gold standard). Maximum dorsiflexion was achieved by asking the patient to take a step forward with the contralateral foot and perform as much dorsiflexion as possible in the ankle studied without removing the heel from the ground. For maximum plantar flexion, the patient was asked to take a step back with the contralateral foot and make as much plantar flexion as possible without removing the studied forefoot from the ground. Results  The values obtained in radiographic measurement were higher than those obtained with clinical measurement. When we compared only the results of clinical measurement, the traditional goniometer was inaccurate. According to the radiographic method, the mean leg-foot range of motion was 65.6 degrees. The mean maximum plantar flexion was 34.9 degrees, and the mean maximum dorsiflexion was 30.7 degrees. Conclusions  The most appropriate method for the evaluation of leg-foot range of motion is the radiographic one. The traditional goniometer proved to be the most imprecise clinical method. The mean leg-foot range of motion in healthy young adults was 65 degrees.