Effect of postural differences on the activation of intrinsic foot muscles during ramp-up toe flexion in young men

A Novel Intrinsic Foot Muscle Strength Dynamometer Demonstrates Moderate-To-Excellent Reliability and Validity

“…Participants lay supine with knees bent at 90 degrees of flexion, with the feet flat on the floor and their arms crossed on their chest, as pictured in Figure 2c and Supplementary Video 2. This position reduced the influence of bodyweight on plantar pressure, as increased postural demand has been shown to increase IFM recruitment, 35,36 and the amount of ankle plantarflexion theoretically allowed for extrinsic muscles to be involved to a smaller degree. 37 Further, it was easier to maintain a standard testing position between patients compared to a seated or standing position.…”

“…While standing, an individual's bodyweight or forward lean during the test could increase loading onto the toes and increase their force output, given that increased postural demand leads to increased IFM activation. 35,36 Further, forward leaning ability correlates highly with ankle dorsiflexor and plantarflexor strength, 46 which means that those who can lean forward more during this type of test could falsely inflate their output. In a sitting position, which has previously been used for IFM strength tests, joint angles can vary based on anthropometric measurements, and individuals are still able to lean forward to affect force production.…”