Human locomotion is diverse and complex. There are numerous forms of locomotion, such as walking, running, crawling, hopping, and swimming. During gait, we roll through our feet as the torso spirals, propelling the body in a change of location into external space.
As individuals, we develop our unique body movement style analogous to a signature. Each person has their own body signature, a particular stance, or way of positioning oneself. If standing, walking, or running, the body changes as the feet respond to motivation, varied ground surfaces, and ground force reaction (GFR).
Our feet are the sensory and motor drivers for movement. A ground force reaction (GFR) occurs when the feet are in contact with the ground. The ground applies a force on the body, and the reaction is in an equal and opposite direction (Newton’s Third Law). Your body exerts a force (your body weight), and in response, the ground pushes back with an equal force, producing relative uprightness. How and where the contact is made by the feet stimulates a pathway of movement traveling through the body. The structure and function of the feet determine how this pathway is directed. Knowing the how and where contact points strike the ground (or footbar) can target desired activation for training. (Black 2022 p.7)
A key to fostering healthy feet is understanding and seeing whole-body movement with a focus on foot function and structure. We have our individual foot signature. Naming it by a static position lacks the information needed for effective programming. The names for foot appearances are “flat feet” or “high-arched.” Anatomical names are pronated for flat and supinated for high. The foot posture labels are a way for us to identify the foot shape. The shape alone does not indicate the function or foot health, positive or negative. The feet may appear flat, but are they able to spring? Or a sprung foot, can it become a mobile flatter foot to accept the loading of one leg in the mid-cycle of gait? The feet require both mobility, a “flattened” foot (pronated) for receiving the ground in stance and shift to a “sprung” foot (supination) for propulsion.
Observing the global view helps determine the response to the load on the feet. The weight distribution of each foot during gait is determined by the movement pathway of the center of mass (COM). (Black 2022 p. 9) The COM is defined as a point where the body mass is distributed in one place. (Ebbecke 2023) It is commonly considered to be located below the navel, approximately 10 cm near the hip joint. However, the COM changes as movement occurs. (Tesio 2019) The weight distribution changes as the COM moves from heel to toe.
The movement above the foot at the tibia, fibula, femur, and pelvis contributes to the foot’s ability to pronate or supinate. The movement of the foot is produced by the moving leg relative to a fixed foot. Primarily, the movements are in two planes, frontal and transverse. Pronation requires dorsi flexion, the tibia gliding anteriorly over the talus, and tibial internal rotation. Supination is plantar flexion, the tibia gliding posterior over the talus with tibial external rotation. (Centered p.12)
The foot function adapts when there is a lack of synergy of the relative leg and foot movements. It will alter how the person responds, changing their movement pathway. Over time, the altered movement pathway changes the look and function of the feet.
Specific movements targeting an issue with the feet, such as bunions or feet that do not spring (pronated), are helpful when the sequencing addresses the foot to pelvis relationships. For example, in knee and hip flexion while weight bearing, if the ankle lacks dorsi flexion, tibial internal rotation, and rearfoot eversion, the body’s weight distribution lands on the lateral side of the foot. Which then impedes balance and disturbs the knee and hip mechanics. The first metatarsal-phalangeal (MP) joint is unable to flex to achieve ground contact. The forces are repetitively landing in a way that may malformed the foot. Feet exercises help make positive changes to the foot, easing discomfort and possibly changing the structure.
A common Pilates training technique uses the toe corrector to activate 1st MP flexion and abduction. To isolate the toe without addressing the whole leg is under-training the potential for efficient weight distribution on the foot. It is necessary to evaluate the forefoot-rearfoot synergy, as well as the ankle and tibial rotation. Then, include these movements within the exercise. In this video, the foot corrector is used to load the foot, including ankle dorsi flexion with forefoot-rearfoot synergy. Cueing the dome of the foot without increased or decreased pressure on the band activates the intrinsic foot-building strength in the transverse arches. Follow this exercise by standing on a block, using the toe corrector in coordination with ankle dorsiflexion and rearfoot eversion, and tracking the tibial rotation. Addressing the person’s movement signature relative to the weight distribution on the feet will meaningfully help the feet structure and function become a more efficient receiver of the ground and body.
References
Black, Madeline; “Centered: Organizing the body through kinesiology, movement theory, and Pilates techniques” 2nd edition 2022 Handspring Publishing Limited, UK
Ebbecke, Jonas blog post https://biomechanist.net/center-of-mass/ 12-05-2023
Tesio L, Rota V. The Motion of Body Center of Mass During Walking: A Review Oriented to Clinical Applications. Front Neurol. 2019 Sep 20;10:999. doi: 10.3389/fneur.2019.00999. PMID: 31616361; PMCID: PMC6763727.
Madeline Black, NCPT, is the author of Centered 2nd edition (Handspring 2022). Her widely respected accomplishments in the field of movement and fitness have fueled her rise as an international leader in Pilates, and movement education . She developed the Madeline Black Method™, helping people achieve their fullest movement potential. Madeline teaches and presents her work in over 25 countries worldwide.
