Spring in the Arches

Active movement leads to proper alignment

By Mary Ann Foster
[The Science of Movement]

Our feet contain a series of longitudinal and transverse arches that function as spring mechanisms, essential to the musculoskeletal health of the feet and the entire body. The medial arch, with its thick plantar ligaments and muscular tendons crossing the arch of the instep, has been compared to the architecture of tie-rod and truss roof beams. The ligaments and tendons stretch under load, then rebound like springs, contributing elastic energy to gait.
The flexibility of the arches can be observed in how the instep pronates and slightly flattens when a person balances on one foot. Many people mistake this flattening effect for a dysfunctional condition and then try to hold up their arches. Chronic holding up is not recommended because it leads to adaptive shortening, joint rigidity, and myofascial pain. In the arches, it also pulls the joints into a close-packed, supinated position, which restricts range of motion.
The best way to develop the arches is with active movement that engages intrinsic and extrinsic muscles (those contained entirely within the foot, and those that originate or insert elsewhere) to pull the bones into place and lift the arches. For example, a person can practice consciously pushing off with the toes on each step during a long walk. This will strengthen intrinsic muscles in the foot, improve joint mobility, and tune up the spring mechanism.
Although feet are incredibly sturdy, they are prone to progressive musculoskeletal dysfunction from poor alignment that twists the foot and restricts range of motion. Some massage clients, particularly seniors, suffer from chronic myofascial foot pain associated with hyperpronation, or “fallen arches.” Hyperpronation can be rigid and permanent; this occurs when supporting tissues have been ruptured or are too flexible, in which case the medial arch only flattens when weight-bearing.  

Neutral Position
Restoring normal flexibility to rigid arches requires an understanding of the neutral position of major joints in each part of the foot. To assess the neutral position of ankle joints, look at how the feet align in a standing posture. In joint neutral, the Achilles tendons are relatively vertical; the talus and calcaneus align the subtalar joint in a position between inversion and eversion.
Joint neutral can be assessed in the midfoot by the shape of the arches. Taut ligaments and tendons provide tensional support like a string on a bow: they bend the arches and hold the bones in place with compressive forces. Each arch has a keystone, which is the block braced in the middle (Image 2). The navicular is the keystone of the medial arch, so it sinks under load and recoils as weight is lifted off the foot.
In the forefoot, joint neutral can be assessed by the degree of perpendicularity between the longitudinal and transverse arches. The long metatarsal bones and toes form five rays that, in a standing posture, are relatively parallel to each other and are perpendicular to the transverse arches.

Supination and Pronation in Walking
The spring mechanism in the foot works best when the joints are optimally aligned in neutral on heel strike, which allows the normal range of supination and pronation that occurs as a person rolls through the foot from heel to toe. From heel strike to toe-off, weight follows a curved pathway of pressure (Image 3). The foot supinates on heel strike while weight rolls along the lateral arch; the foot then pronates as weight spreads across the ball of the foot into a push-off with the toes.
Fallen arches cause a pronation twist, medially rotating the forefoot against the midfoot and ankle. This places the joints in an open-packed position that puts tensional stresses on the soft tissues, which stretch-weakens them and compromises the spring mechanism. Clients with hyperpronated feet tend to walk with a stiff, flat-footed gait marked by a restricted range of push-off in the toes. Try walking without bending your toes to feel how vital push-off is for a normal range of motion.
It is also important to push off with all five toes for optimal sagittal tracking in the foot and lower limb. This stretches the tendons and ligaments in the arches evenly, triggering reflexive contractions and elastic rebound in a balanced way. These alignment principles also apply to active or passive stretching of the ankle flexors or extensors: as you move the joints, flex and extend them along a sagittal track, maintain a neutral position of the ankle between inversion or eversion, and avoid twisting the foot.

Exploring Technique
Restoring Arches in Stiff, Flat Feet
1. Slowly and gently compress the underside of the midfoot, placing the joints and intrinsic muscles of the midfoot in a close-packed, shortened position.
2. Hold for several seconds with the intent of triggering a relaxation response in the muscles.
3. When the tone changes, apply light traction and stretch the arches.

Mary Ann Foster is the author of Therapeutic Kinesiology: Musculoskeletal Systems, Palpation, and Body Mechanics
(Pearson Publishing, 2013). She can be contacted at mafoster@somatic-patterning.com.