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48 Factors affecting muscle function - Coggle Diagram
48
Factors affecting muscle function
Intrinsic factors
size and
number of fibers
extrinsic to the muscle
is the nervous system recruitment pattern
These factors include:
Velocity of a muscle contraction
is affected by:
Recruitment order
of the muscle fibers:
Types of muscle fibers
in the motor unit:
Units with type II muscle fibers
can develop
maximum tension
more rapidly than
units with type I muscle fibers
Length of muscle fiber:
Long fibers
have a higher shortening velocity
than do short fibers
Units with
slow conduction velocities
are recruited first
Magnitude of the active tension
is affected by:
Size of motor units
Larger units
produce greater tension
Number and size
of muscle fibers
in a cross section
of the muscle
The larger the cross section
the greater the amount of
tension that a muscle may
produce
Number of motor units firing
The greater the number of
motor units firing in a muscle
the greater the tension
Frequency of firing
of motor units
2 more items...
Types of joint and location
of muscle attachments
Structure of the joint determines the
type of motion that will occur
Flexion and
extension of the joint
as well as ROM
Muslce’s location
or line of action relative to the joint
determines the motion
Muscles that cross the anterior aspects
of the joints of the upper extremities
truck and hip
are
flexors
Muscle located on the
posteriori aspect of the joints
are
extensors
Muscle located laterally
serve as abductors
and located medially
serve as adductors
(some times can serve as rotators too)
Muscle whose distal attachments
are close to a joint axis
are usually able to produce
a wide ROM
of the bony lever
to which they are attached
Muscle whose distal attachments
are far away from the joint axis
are designed to provide
stability for the joint.
A muscle provides maximum joint stabilization
at which its compressive component
is greatest
Number of Joints
An efficient movement pattern
is through the coordinated efforts of
single-joint and multi-joint muscles
Number of joints
the muscle crosses
determines the muscle function
Single joint muscles
Recruited primarily in
concentric and isometric contractions
Simple movement is performed at one joint
Multi joint muscles
To control the
fine regulation of torque
during dynamic movements
(more eccentric contractions)
Passive insufficiency
Sensory receptors
Velocity of a muscle contraction
Magnitude of the active tension
Types of joint and location of muscle attachments
Number of Joints
Passive insufficiency
Sensory receptors