Biomechanic View for Tàijíquán
Numerous views can be found of how Tàijíquán utilizes the body. Some of these have been mathematically modeled to different degrees. Others are currently more conceptual models.
Traditional modeling of biomechanics
Standard models of movement utilize the concept of sticks (bones) and rubber bands (muscles). The rubber band connects the origin to insertion. When a muscle/tendon folds over a joint, a pulley is introduced to the model.
Figure 1: Standard model of walking structure generated in OpenSim
Anatomy Train model
Anatomy trains, also known as myofascial meridians, are intended to describe the pathways of functional force that travels through the body. There are 12 sets of these anatomy trains identified in the different layers of the fascia.
This chain concept extends the standard model to longer connections through the body with many additional insights and challenges.
Figure 2: Some lines of the anatomy train are shown in these myofascial meridian maps. The deep arm lines are shown on the left, the superficial arm lines in the middle, and the front view of the spiral lines on the right
Biotensegrity model
The basic concept is for a healthy body, the bones float in a balance of tension created by the soft tissue. The detailed mechanism is still being developed. This probably needs to involve the structure of the joint capsule, the interactions of different regions of the fascia, and the muscle fiber.
It is a challenge to generate a model with the correct properties and correspondence to the current understanding of the human anatomy.
Figure 3: Biotensegrity model that approximates the human body by Tom Flemons
Membrane Model
The fascia are membranes that intersect each others as they wrap around and fill the spaces in the body. These can be mathematically modeled using finite element analysis and similar methods. The membranes can mostly be modeled as 2-dimensional objects with varying properties.
Figure 4: Some of the epimysium fascia of the upper arm and their response as a membrane due to a contraction of the long bicep muscle compared to a stretching of the muscle.
Hydrodynamic Model
The fluid of the fascia lies between two collagen layers that are connected by a ”webbing” of collagen fibers. The properties of this fluid varies, exerting different forces around the body influenced by numerous factors.
Including these factors into a model can provide a more realistic understanding of the interaction of Tàijíquán and fascia.
Balloon Model
The balloon model has several different variations of design and provides a simplified combination of a membrane with a hydrodynamic model. In most versions, the superficial fascia is treated as a balloon with varying elastic properties. In one case, the epimysium is shaped by contractions of muscle fibers. In another case, the epimysium is also treated as balloons. There is a viscous fluid that fill the space of the balloons.
Tai Chi, Fascia, and Math 