what are non-contractile tissues

ligaments, tendons, joint capsules, fascia, skin, and non-contractile components of muscle

what determines functional mobility (2 factors)

active neuromuscular control, passive extensibility of soft tissues

what soft tissues commonly impair mobility

muscles, tendons, ligaments, joint capsules, fascia, skin

what adaptations occur in soft tissue with immobility

shortening, adhesions, loss of sarcomeres, increased stiffness, reduced ground substance, decreased tensile strength

define elastic tissue behaviour

tissue returns to original length after stretch; temporary deformation

define viscoelastic behaviour

time-dependent deformation; elongates if stretch is held; partially returns to original length

define plasticity in soft tissue

permanent length change after sustained stretch; goal of therapeutic stretching

what is the toe region of the stress-strain curve

slack is taken up; collagen fibers straighten; occurs up to normal ROM

what is the elastic range

tissue deforms but returns to original length; safe zone

what is the plastic range

collagen fibers begin to fail/realign; permanent length change occurs

what is necking

collagen significantly weakened; tissue close to failure; danger zone

define creep

permanent deformation when a constant load is applied over time

what stretching principle is based on creep

static stretching, serial casting, low-load long-duration stretching

how do you change length in non-contractile tissue

slow, long-duration stretching -> collagen realignment + ground substance redistribution

what are the components of contractile tissue

muscle fibers + non-contractile layers (epimysium, perimysium, endomysium)

what do muscle spindles respond to

length changes and velocity of length change

what is the function of the muscle spindle

triggers stretch reflex -> contraction of muscle; reciprocal inhibition of antagonist

what is the clinical implication of muscle spindles

stretch slowly to avoid triggering the stretch reflex

what does the Golgi Tendon Organ (GTO) respond to

tension changes (active or passive)

what is the function of the GTO

inhibits alpha motor neurons -> autogenic inhibition -> muscle relaxes

what is the clinical implication of GTO activation

sustained stretch promotes relaxation; basis for PNF hold-relax

what is hypomobility

adaptive shortening of soft tissue -> decreased ROM

what factors contribute to hypomobility

immobilization, sedentary lifestyle, postural malalignment, impaired muscle performance, trauma/scar tissue

what stage is stretching usually applied in healing

late sub-acute and chronic stages

what is a myostatic contracture

adaptive shortening of musculotendinous unit; decreased sarcomeres; responds to stretching

what is a pseudomyostatic contracture

hypertonicity from CNS lesion; constant contraction; requires inhibition techniques

what is an arthrogenic/periarticular contracture

intra-articular pathology limiting arthrokinematics; needs joint mobilization + stretching

what is a fibrotic/irreversible contracture

non-extensible fibrotic adhesions; requires prolonged stretching, heat, friction techniques

why is alignment important during stretching

isolates target muscle and prevents compensations

why is stabilization important

prevents unwanted movement and ensures effective stretch

what intensity of stretch is recommended

low-intensity -> safe, comfortable, promotes long-term change

what is the standard stretch prescription

30 seconds/side, 3 reps, 1-2x daily

why must stretch speed be slow; prevents stretch reflex and reduces risk of guarding

what is static progressive stretching

stretch held until tension decreases; then advance further

what is the purpose of applying cold after stretching

"sets" tissue in lengthened position and helps maintain new ROM

what must be documented when prescribing a stretch

muscle, description, duration, reps, frequency