Terminologies and force production Flashcards
What is the difference between penniform and longitudinal muscles, what advantages do they have over each other?
Penniform allows a larger cross sectional area for more muscle fibers to reside in, hence, allowing to produce a substantial amount of force for the muscle.
Longitudinal muscles are long and thin, which allows for speed of contraction, however, its cross sectional area is small, hence, it does not provide as much force as penniform as there are lesser muscle fibers.
What is synergist in muscular terms? When will we need it?
Synergist assists agonist muscles in performing a desired action. They act as joint stabilisers and rotation neutralisers. They are activated when agonist muscles are fatigued or when additional external resistance is needed.
What is co-contraction?
Co-contraction refers to when the agonist and antagonistic muscles contract together as a joint must be stabilised. E.g. During a dumbbell rowback, torso must neutralise spine to move dumbbell efficiently.
What must muscles do to achieve optimal performance of movements? What does poor and inefficient movement result in?
The muscles must work together and stabilise the joint simultaneously. Weak stabiliser muscles such as deep abdominals, hip stabilisers, scapula retractors) may lead to pain/injury.
What is kinetic chain movement and what is it used for?
It focuses on improving stabiliser musculature and is most commonly used in functional rehabilitation. The concept of kinetic chain movement is that our body is a chain with a joint being a link.
What is the 2 types of kinetic chain movements? What are their differences and which is better?
Open and closed ended. Open ended chain refers to the end of the chain furthest from the body is not fixed/free, e.g. in a sitting leg raises, the end of the chain is the foot and it is free. While the close ended refers to the end of the chain furthest from the body as fixed. E.g. in a feet during squats.
Close ended chains are usually better as they emphasise on the compression of joints, allowing for more stability, moreover, they activate more muscles and joints which improves neuromuscular coordination and stability.
What is the difference between joint mobility and joint stability?
Joint mobility refers to the range of uninhibited movement around a joint and joint stability refers to the maintainance or control of a joints position or movement.
Can you have joint mobility without joint stability?
Yes however it will lead to injury or muscle imbalance due to the unnatural force acting on the joint mobility, it overtaxes certain muscles and causes muscle imbalance. This is caused by improper technique/form, poorly designed equipment.
