Topic 4: Movement Analysis Flashcards Preview

SEHS > Topic 4: Movement Analysis > Flashcards

Flashcards in Topic 4: Movement Analysis Deck (65)
Loading flashcards...

Explain the role of neurotransmitters in stimulating skeletal muscle contraction

-Neurotransmitters are chemicals that are used for communication between a neuron at the synapse and another cell.
-Acetylcholine is the primary neurotransmitter for the motor neurons that innervate skeletal muscle and for most parasympathetic neurons.
-generally an excitatory neurotransmitter, can have inhibitory effects at some parasympathetic nerve endings, such as the heart. In biochemistry, cholinesterase is an enzyme that catalyzes the hydrolysis of the neurotransmitter acetylcholine into choline and acetic acid, a reaction necessary to allow a neuron to return to its resting state after activation.


Fast twitch muscle fibre
(Type 2a)

-contract quickly
-give sharp, powerful muscle contractions
-dont use oxygen
-suited for activities with bursts of strength and power
-tire quickly
-have fewer mitochondria
-metabolise ATP more quickly
-have a lower capillary volume ratio
-more likely to accumulate lactic acid


Slow twitch muscle fibre
(Type 1)

-take longer to contract
-give long sustained muscle contractions
-not as powerful
-have a good oxygen supply
-suited to activities which require long term energy
-have more mitochondria
-store oxygen in myoglobin
-rely on aerobic metabolism
-greater capillary to volume ratio
-produce ATM more slowly


Sagittal axis

passes horizontally from posterior to anterior and its formed by intersection of sagittal and transverse planes


Frontal axis

passes horizontally from left to right and is formed by the intersection of the frontal and transverse planes.


Vertical axis

passes vertically from inferior to superior and is formed by the intersection of the frontal and sagittal planes.


Isometric contraction

in this form of contraction the muscle length remains constant. It occurs when muscle force balances resistance and no joint movement occurs
-there is generally no movement resulting from this type of contraction
-pushing against a fixed object


Isotonic contraction

an increase in tension results in changes in skeletal muscle length


concentric contraction

concerns muscle actions that produce a force to overcome the load being acted upon.
(positive work)
cause the muscle to shorten as it contracts


Eccentric contraction

Refers to muscle action in which the muscle force yields to the imposed load.
(negative load)
muscle lengthens as it contracts


Isokinetic contraction

When a muscle contracts so that the body segment to which it is attached moves at a constant speed around the joint, rarely found in sport.


Explain the concept of reciprocal inhibition

When an agonist contract to move a body segment, it is usual for the antagonist (the muscle with the opposite concentric contraction action) to relax. This means that the agonist is not being opposed by any muscle torque acting in the opposite direction of the motion. This is an automatic action controlled by neurons. When the agonist motoneuron is stimulated the motoneuron to the antagonist is inhibited preventing it from contacting strongly


Type 2b

generate the fastest contraction times and largest forces, but fatigue at a high rate and so cannot maintain contractions for a long period of time.


Movement of synovial joints: non-axial

In gliding joints the bones slide in rotation to each other. Therefore, there are no axes of rotation in this type of joint


Movement of synovial joints:

in hinge joints and pivot joints there is only one axis of rotation. This means that the structure of the bones as the joint restricts rotation to movement around one axis only.


Movement of synovial joints: Biaxial

as condylar joints and saddle joints there are two axes of rotation and therefore the bones can move in two different ways.


Movement of synovial joints:

ball and socket joints such as the shoulder and hi allow rotation around three axes. Therefore, these bones permit the greatest movement, as they allow the limbs attached at them to move through a large volume of space.


The anteroposterior axis

going back to front


The transverse axis

going from left to right


The vertical axis

going from top to bottom


Motion in sagittal plane: Flexion

closing of the joint angle around the transverse axis at the joint


Motion in sagittal plane: Extension

Opening of the joint angle around the transverse axis at the joint


Motion in the frontal plane:

Opening of the joint angle around the anteroposterior axis at the joint


Motion in the frontal plane:

Closing if the joint angle around the anteroposterior axis at the joint


Motion in the transverse plane:
Medial rotation

The anterior surface of the bone movers towards the medial aspect of the body


Motion in the transverse plane:
Lateral rotation

The anterior surface of the moving bone moves towards the lateral aspect of the body


1. Dorsi flexion
2. Plantar flexion

1. flexion of the ankle
2. extension of the ankle

These movements move the foot up and down in the sagittal plane.


1. Pronation
2. Supination

1. Medial rotation of the radio ulna joint
2. lateral rotation on the radio ulna joint

These movement allow the forearm to rotate even when the elbow is flexed.


1. Eversion
2. Inversion

1. Medial rotation of the ankle joint
2. Lateral rotation of the ankle joint

These movements involve 'rolling' of the foot at the ankle.
Inversion=sole of foot inwards
Eversion=sole of foot outwards


1. Horizontal Abduction
2 Horizontal Adduction

1. Opening of the joint angle around the transverse plane.
2. Closing of the joint angle around the transverse plane
(both: when the body segment has been flexed to 90)

Common at shoulder.

-Flexed 90 then brought to midline of body horizontal=horizontal adduction
-if horizontally away from midline= horizontal abduction