What is stress relaxation?
viscoelastic structures, such as muscle tendon unit. When elongated to a specific length and held at this position the internal tension decreases with time.
creep occurs when an MTU is elongated to a specific length, and then allowed to con't to elongate as stress relaxation occurs. Creep is partially responsible for the immediate increase in joint ROM.
When stretching a muscle joint complex, what structures are influenced?
joint capsule, ligaments, nerves, vessels, skin, MTU
What is ballistic stretching?
Stretching near the limit of available ROM and then cyclically loading the muscle joint complex (bouncing at end range). Indicating for preconditioning a muscle joint complex for activities such as sprinting, high jump, or other events dependent on elastic energy.
Define static stretching:
Holding a muscle joint complex at a specific ROM until a stretch is perceived. Held static.
Describe some commonly used proprioceptive neuromuscular facilitation (or active inhibition) stretching techniques:
hold(contract)-relax: pt placed into a comfortable stretch and pt contracts the target muscle group for 5-10s . The pt then relaxes and the stretch is increased. Repeat. Hold-relax antagonist contraction: muscle stretched to a comfortable position, contracts target muscle group for 5-10s, then contracts agonist for 5-10s Antagonist contraction: stretch held and opposite muscle group contracted 5-10s, then repeated as ROM is increased.
What is the optimal number of stretch repetitions?
HOw is the optimal number of stretch repetitions determined?
According to Taylor et al, 80% of the MTU length is achieved by the fourth stretch with the majority occurring after the first stretch.
What is the optimal stretch time?
between 15-60s, most advocate for 15-30s.
How often must stretching be performed to maintain gains?
At least every 24 hours.
How long will gains realized from stretching be retained?
Does muscle stretching increase performance?
Depends on activity. Ballistic for sport dependent on elastic energy. Stretching decreases performance in elite runners and sprinters; but research supports stretching that can increases performance related to economy of gait.
Does stretching decrease the chance of injury?
Yes, usually. Flexibility imbalances is the key to prevention.
Does stretching decrease pain?
Yes, research supports stretching decreases DOMS
Should a muscle joint complex be warmed up to optimize the effects of a stretch?
Not necessarily. It makes sense logically, but research has shown that stretching with or without a warm-up yields the same results.
Should joint mobilization precede stretching?
Yes, joints exhibiting decreased joint play should be mobilized before stretching to decrease the effects of abnormal joint compression and distraction.
What stretching techniques results in the greatest flexibility gains?
Static hamstring stretch via systematic review was superior to PNF. But it is difficult to state this with certainty.
What effect does stretching position have on hamstring flexibility gains?
non-dependent on position for hamstrings
Does age influence the extensibility of muscle and tendon?
as age increases MTU decreases in extensibility especially in the calf which is important for ambulation, balance, and fall prevention.
Does stretching the gastroc muscle in subtalar supination result in greater DF ROM?
no difference with change in ankle position
ODes stretching alter joint position sense?
a brief stretching regimen 30s x3 had no effect on knee joint position sense.