Lesson 2 - The Role of Proprioceptors

Question 1

What is Proprioceptive Neuromuscular Facilitation (PNF)?

Answer 1

• An advanced stretching technique.
• Considered to be one of the most effective forms of flexibility training for increasing range of motion.
• There are a few different PNF techniques but the most practical is CRAC (Contract - Relax - Antagonist - Contract).

Question 2

What are muscle spindles and what do they do?

Answer 2

• These are very sensitive proprioceptors that lie between skeletal muscle fibres.
• They are often called stretch receptors as they provide information to the CNS about how far or how fast a muscle is being stretched.
• The CNS then sends an impulse back to the muscle telling it to contract, which triggers the stretch reflex.
• This reflex action prevents overstretching thus reduces the risk of injury.

Question 3

What are Golgi Tendon Organs and what do they do?

Answer 3

• These are found between the muscle fibre and tendon.
• They detect levels of tension in a muscle.
• When the muscle is contracted isometrically in PNF, they sense the increase in msucle tension and send inhibitory signals to the brain which allows the antagonist muscle to relax and lengthen.
• This is known as autogenic inhibition.