This is an excerpt from Dynamic Alignment Through Imagery - 2nd Edition by Eric Franklin.
Imagery Exercises for the Transverse Tarsal Joint
1. Long-axis tarsal twist: Firmly hold your heel with one hand. With the other hand, twist (supinate and pronate) the forefoot along the long axis of the foot. Imagine you are wringing a towel while keeping it in a straight line. Visualize the facet of the navicular spinning on the head of the talus. Notice that the medial aspect of the transverse tarsal joint is moving more than the lateral. After twisting one foot, compare the feel and balance of both feet in a standing position.
2. Oblique-axis tarsal twist: Firmly hold your heel with one hand. With the other hand, twist (supinate and pronate) the forefoot along an oblique axis through the foot. Supinating the foot will now involve some plantar flexion and adduction; pronating the foot will involve some dorsiflexion and abduction. Your imaginary towel is now twisting and flexing at the same time. After twisting one foot, compare the feeling of both feet in a standing position.
3. Imagining the transverse tarsal action in the standing leg in flexion and extension: Stand in a comfortable position. Flex our lower limbs while visualizing the subtalar and transverse tarsal joints. Imagine a slight unwinding of the foot spiral as you bend your legs. Imagine a slight amount of foot spiraling as you stretch your legs. If you prefer anatomical imagery, imagine a slight amount of supination in the transverse tarsal joint as you bend your legs and a slight amount of pronation in your transverse tarsal joint as you stretch your legs. Notice what happens if you perform the opposite action: pronation of the transverse tarsal joint during lower-limb flexion. Your foot as a whole will tend to overpronate and may feel like it is collapsing inward.
4. Heel as a boat on the waves: Supinate and pronate your feet while in a standing position. Imagine the heel to be a boat rocking on the waves (figure 11.40). As you pronate your foot, the top of the heel-ship will rock inward; however, the transverse tarsal joint allows the midfoot and forefoot to counterbalance in the opposite direction of supination. As you supinate your foot, the heel-ship rocks outward and the transverse tarsal joint and forefoot oppose the action by pronating.