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.
5. Forefoot and hindfoot twist: Take an object such as this book (you may walk along the outer edge of this book; it’s included in the price) and place it under the lateral side of your forefoot. Notice how the forefoot pronates and the hindfoot relatively supinates to keep your talus upright. Now place the book under the medial forefoot. In this case, the forefoot is supinating while the hindfoot is relatively pronating to keep you from losing your balance.
6. Uneven ground: Take a walk over imaginary uneven ground. Visualize a variety of odd shapes to step on and watch how your foot adapts. Now collect some real objects that cannot harm your feet, such as small stones. After experimenting for a while with walking on real objects, try walking over the imaginary uneven ground again.
7. Rubber raft: Imagine your foot to be an inflatable rubber raft. Such a raft can readily adapt to all kinds of waves because it is able to twist along its longitudinal axis. Watch the twisting adjustments of the raft as you walk along a rocky road (figure 11.41).