Dear Dr Shavelson, your question is very interesting. Considering the feet center of pressure, it is important to keep in mind that the coupling of posture and gait is well accepted to influence each other. For this, consider the postural system as being all segments above the pelvis, and the gait system as being all segments below the pelvis. Therefore, in this example, an impairment in the postural system will affect the gait system and impairment in the gait system will affect the postural system.

For better understand, consider that during a normal and comfortable walking a person is confident that the foot which is in the swing phase will strike the ground for the next stance phase. Normally when the foot strikes the ground muscles react by plantar flexion, the leg rotates externally, the thigh rotates internally, the ipsilateral iliac rotates externally. This is to say: the stability of the entire body during normal walking is possible owing to the coupling of segments, i.e. the stability of the entire body is guaranteed by a series of transversal-counter-rotations in a vertical axis. In this example, an impairment in the coupling of segments, for instance: the coupling between trunk and pelvis can cause maladaptation—this is well documented in the scientific literature. However, your hypothesis stands if you can teach your patient or athlete on how to timely react to control the position (or movement) of his or her body segments when the foot strikes the ground.

Yours is a straightforward question. Instead, my answer is quite vertical as the force we need to control during walking or in many physical actions performed in our daily life. With this, I want to say that the gravitational force seems to offer a more natural therapeutic effect. More specifically, the vertical component of gravity offers another possibility for optimising the center of pressure, that is: by learning how to control a vertical force. This would optimise the controller (i.e. CNS). And for this, a treatment composition needs to facilitate the control of a vertical force by reducing degrees of freedom to only one. In this manner, the controller can learn the relevant information to process for then optimise the physical goal.

In the attempt to optimise the controller and resolve motor impairments, an elemental approach to recalibrate the neuromuscular system is actually available. The approach is based on Classical Learning which adopts a vertical force as the stimulus to be conditioned. This treatment can resolve a large list of motor impairments and is very likely to improve the feet center of pressure. More specifically, this is a Serial Reaction Time (SRT) task. By reducing degrees of freedom to only one, the patient learns a movement scale in the implicit memory system. Precisely, this treatment is designed to resolve impairments related to the postural system but the effect on the gait system is more than satisfactory. However, in the case of the gait system, a different approach is available as well. Please, find an article below.

Article A Learning Process Which Improves Symmetry in the Dynamics o...

Kind regards

VMD

The depth of understanding of your response is beyond much of mine as I am so focused on the gait system. Thank you for your input.

1. The RELATIVE hip joint internal rotation that occurs in the transverse plane is created by internal rotation of the femur and rotation of the pelvis to the left.  Both of these REAL bone motions are created by subtalar joint eversion / pronation that is created by lateral heel contact.  The calcaneus everts which is converted into transverse plane rotations of the bones above because of the angle of the subtalar joint axis.  Frontal plane motion in the foot (eversion) is converted into transverse plane motion of the leg (internal rotation).  The lower leg, femur, and pelvis all rotate in the same direction.

At heel contact, I believe the foot pronates at the subtalar joint and the leg internally rotates(both briefly).

As the foot enters midstance, is the forefoot is either stable or rigid there is a supinatory moment created and then the leg and thigh externally rotate.

2.My 2019 understanding is that the CNS (conscious) at is not capable of the level of rapid firing that would be required throughout the body in milliseconds.

This leads to the poorly researched thought that the piezoelectric chemical reactions involving the myofascial connective tissue envelop is also a part of the controller (subconscious).

Dennis

Hi Dennis, considering a normal speed of a forward walking. We can say that walking is composed of a series of medial-lateral rotation of the body which is relative to a certain target direction. The important point to keep in mind is that: the relative rotation of each segment of the body itself facilitates control of the relative stability of the vertical position (maybe could be interesting to imagining the phase when the foot is stationary during a walking - more specifically the bottom to the top reaction of forces). The former then allows for more control of the intended movement or action. Best regards, Vinicius.

VMD

I am not sure why you completely changed the subject and content of this question as asked and failed to address my response to your original post?

All I can say is that your second post, for me, has no clinical applicability or validity and I wish you best regards in return.

Dennis

Craig:

1. Do you have any "normal" or "optimal" values for cohorts regarding pressure measurements that can be clinically applied n-1?

2. Is any of your research practically applicable to the casting, prescribing or fabrication of custom foot orthotics or the development of Training Programs, n=1?

Dennis

The literature continues to use center of pressure as the gold standard in pedobariography in spite of the fact that no research has shown that improving the center of pressure on a pressure mat will do anything to improve any issues or the function of the feet and posture in cohorts.

Remember, the center of pressure is a made up value that has inter and intratester flaws.