Composition and Mechanical Characteristics of Soft Tissue
- Soft tissue is composed of collagen, elastin, and ground substance.
- Fibroblasts are responsible for producing soft tissue fibers and ground substance.
- Elastin confers stiffness to the tissue, while collagen limits deformation and protects tissues from injury.
- Human soft tissue is highly deformable and its mechanical properties vary among individuals.
- Stiffness and damping resistance of soft tissue are correlated with the mass, velocity, and size of the striking object.

Pseudoelasticity and Residual Stress in Soft Tissue
- Soft tissues exhibit viscoelastic properties but can be approximated by a hyperelastic model after preconditioning to a load pattern.
- Preconditioned soft tissues still present hysteresis, so the mechanical response can be modeled as pseudoelastic.
- Soft tissues usually have residual stress in their physiological state, which may be released when the tissue is excised.
- Physiologists and histologists must be aware of residual stress to avoid mistakes in tissue analysis.

Remodeling and Growth of Soft Tissue
- Soft tissues can grow and remodel in response to chemical and mechanical changes.
- Fibroblasts produce tropocollagen at a rate proportional to these stimuli.
- Remodeling plays a role in soft tissue diseases, injuries, and changes in mechanical load.
- Growth and remodeling are involved in the thickening of cardiac muscle in response to increased blood pressure.
- Mechanobiology studies the relationship between stress and growth at the cellular level.

Imaging Techniques for Soft Tissue Visualization
- Choosing an imaging technique for visualizing soft tissue extracellular matrix (ECM) components requires considering factors such as resolution, contrast, artifact count, and volume data acquisition.
- Transmission Light, Confocal, Multi-Photon Excitation Fluorescence, Second Harmonic Generation, and Optical coherence tomography are different imaging methods with varying properties and resolutions.
- The resolution of the imaging technique needs to be approximately 0.5 μm to capture the 1-2 μm thick collagen fibers.
- Volume data acquisition allows following fiber bundles across the volume.
- Fixation of soft tissue in formalin can cause shrinkage and alter the tissue structure.

Soft Tissue Disorders and Sarcomas
- Soft tissue disorders affect soft tissues in the body and can be difficult to treat and diagnose.
- Soft tissue therapy is an expanding field, and platelet-derived growth factor shows promise in treating soft tissue injuries.
- Soft tissue disorders and rheumatism have overlap, and soft tissue rheumatic disorders is a term used to describe these conditions.
- Rheumatologists specialize in treating soft tissue rheumatic disorders, which can cause chronic pain and difficulty in diagnosis.
- Soft tissue sarcomas are types of cancer that develop in soft tissues and can occur in various parts of the body.
- Diagnosis of soft tissue sarcomas involves imaging and biopsy, and treatment options include surgery, radiation, and chemotherapy.
- The prognosis for soft tissue sarcomas depends on various factors.

Soft tissue (Wikipedia)

Soft tissue is all the tissue in the body that is not hardened by the processes of ossification or calcification such as bones and teeth. Soft tissue connects, surrounds or supports internal organs and bones, and includes muscle, tendons, ligaments, fat, fibrous tissue, lymph and blood vessels, fasciae, and synovial membranes. 

It is sometimes defined by what it is not – such as "nonepithelial, extraskeletal mesenchyme exclusive of the reticuloendothelial system and glia".