A. Structural resistance

Rigid – no deformation

Stiff – resists deformation, but still deforms somewhat

B. Structural adaptability

Elastic – returns to original shape after deformation

Plastic – deforms and remains changed

Viscoelastic – time-dependent response combining elastic and viscous behaviour

Fluid-like – adapts shape and redistributes force in multiple directions

Liquid-like – flows and follows gravity, with minimal shape retention

C. Active function

Contractile – actively generates force (muscle action)