Tone Abnormalities Flashcards
Help produce synergies (particular patterns of movements)
Neural circuits
Refers to the CNS areas originating above the spinal cord
Supraspinal
Volitional movement originates from what?
A sensation, idea, memory, or external stimulus
Neurons in the ____ compare intended movement with sensory input received about the actual movement
Cerebellum
Modulate movement and tone
Basal ganglia
Basal ganglia are composed of what five groups of neurons?
Putamen, caudate, globus pallidus, subthalamic nucleus, and substantia nigra
Receives a rich supply of input from the vision system, auditory system, vestibular system, somatosensory system, and motor cortex
Reticular-activating system
How does the limbic system influence movement and muscle tone?
Via the RSTs and connections with the basal ganglia
What does muscle tone and activation depend on?
Normal composition and functioning of the muscles, the PNS, and CNS
What can result in abnormal muscle tone?
An injury or pathology
Low muscle tone
Hypotonicity
Hypotonicity usually results from what?
Loss of normal alpha motor neuron input to muscle fibers
What causes denervation in a muscle?
When disease or injury of the alpha motor neurons removes neuronal input
What is a possible consequences of abnormally low muscle tone?
Difficulty developing enough force output for normal posture and movement
What is rearborizing?
Each alpha motor neuron remaining in a muscle may increase the number of muscle fibers it innervates by increasing its number of axonal branches
What are some physical agents used for hypotonicity caused by alpha motor neuron damage?
Hydrotherapy, quick ice, E-stim, biofeedback
High muscle tone
Hypertonicity
Hypertonicity is a result of what?
Abnormally high excitatory input compared to the inhibitory input to an intact alpha motor neuron
What are some consequences of high muscle tone?
Contractures, abnormal posture, skin breakdown, discomfort/pain from muscle spasms
What are some interventions used to counter hypertonicity/contractures following a spinal cord injury?
ROM exercises, prolonged stretch, positioning/orthotics to maintain functional muscle length, medications, surgery
What are some causes of cerebral (CNS) lesions?
Cerebral vascular disorders (stroke), cerebral palsy, tumors, CNS infection, head injury
What is another consequence of CNS pathology besides spasticity?
Rigidity
The resting tremor of a patient with Parkinson’s disease is an example of what?
Fluctuating tone that results in involuntary movement
Definition: the underlying tension in a muscle that serves as a background for contraction.
Muscle Tone
Definition: low tone or decreased resistance to stretch compared with normal muscles
Hypotonicity
Definition: high tone or increased resistance to stretch compared with normal muscles
Hypertonicity
Definition: lack of tone or absence of resistance to passive stretch within the middle range of the muscle’s length
Flaccidity
Definition: loss of voluntary movement
Paralysis
Definition: an abnormal, hypertonic state in which muscles are stiff or immovable and in which they are resistance to all stretch regardless of velocity or direction.
Rigidity
Definition: an abnormal, hypertonic muscle response in which quicker passive muscles stretches elicit greater resistance than slower stretches.
Spasticity
True or False: is muscle tone and voluntary muscle contraction distinct from each other
True
What are some quantitative tests/tools used to measure muscle tone?
Dynamometer, Electromyography, and Pendulum Test
What are some qualitative tests/tools used to measure muscle tone?
Clinical Tone Scale, Muscle Stretch Reflex Test, and Ashworth and Modified Ashworth Scale
True or False: position of the patient affects muscle tone and should therefore be considered when measuring.
True
What two myofilaments overlap to form cross-bridges which create muscle contractions
Actin and Myosin
