Resting calcaneal stance position (RCSP):
Patient is positioned in relaxed standing with feet in their angle and base of gait. RCSP is the angle that the calcaneal bisection makes with vertical. Generally considered that it should be vertical or up to 2-3 degrees everted (this theoretically means that no compensation has taken place, unless a rearfoot varus is present). Sobel et al (1999) found a mean relaxed calcaneal stance position in a healthy adult population to be 6.07 (+2.7) degrees everted and in children to be 5.6 (+2.9) degrees everted.
Some have suggested that this should be measured with the contralateral leg off the ground, as this more simulates the single limb stance of dynamic function (single limb stance position).
If inverted more than vertical, this is considered to indicate a supinated position of the subtalar joint. If it is more everted than 2-3 degrees, this is considered to be a pronated position of the subtalar joint. The amount of inverted or everted position as a reflection of subtalar joint position will be dependent on the orientation of the STJ axis in the sagittal plane.
An everted may be referred to as calcaneal or rearfoot valgus in some literature (this classification is based on the ‘compensated’ position of the rearfoot as the reference point, as opposed to the classification that uses the defined subtalar joint neutral position as the reference point).
Clinical use – measure of how far subtalar joint is compensating for a more proximal or distal structural deformity (by pronating or supinating) during static stance in the frontal plane (does not measure the amount of compensation in the sagittal or transverse planes).