Please enable JavaScript.
Coggle requires JavaScript to display documents.
TONE (ABNORMAL (When hypertonicity is present various types of motor…
TONE
ABNORMAL
Flaccidity: Absence of tone and absent active movement & deep tendon reflexes
Hypotonus: Decrease of normal muscle tone i.e. low tone, diminished deep tendon reflexes
Hypertonus: Increased muscle tone and loss of reciprocal inhibition
When hypertonicity is present various types of motor dysfunction may be observed
Spasticity: Increased muscle tone – rapid passive stretch. Clasp-knife phenomena
Clonus: Specific type of spasticity (in mod-severe spasticity). Repetitive contraction in the antagonist in response to rapid stretch
Rigidity (dystonia): Increase in muscle tone of agonist & antagonist muscles simultaneously. Leadpipe, cogwheel
Athetosis: Involuntary slow writhing movements (not evident in sleep)
MUSCLE WEAKNESS
Reduces the person’s ability to maintain posture and initiate and control movement
Weakness occurs as a result of changes in the motor and muscle units that mediate muscle tension
Is the inability of a person to generate sufficient muscle force or tension for normal range of movement
Loss of motor units and decreased firing rate of motor units and changes in recruitment of motor units have been reported in hypertonic muscles of people with hemiparesis > inability to generate sufficient force = recruitment of motor units to produce a particular movement
COORDINATION
Characteristics: smoothness, rhythm, appropriate speed, refinement to the minimum number of muscle groups needed & appropriate muscle tension, tone & equilibrium.
Ability to produce accurate, controlled movement
Role of: cerebellum, frontal & post-central cortex, Basal ganglia, muscles & peripheral nerves, posterior column of spinal cord, proprioception, body scheme, cognition
NORMAL
Normal muscle tone is evident when:
Balanced tone between agonists and antagonists
Ability to selectively move a muscle, or in groups – in coordinated and timed manner
Able to stabilise at axial and proximal joints
Able to shift between stability/mobility and mobility/stability – hypertonia and hypotonia
Able to move against gravity
Muscle tone is the resistance of a muscle to passive elongation or stretch. If limb is placed passively (by someone else) position can be maintained and slight resistance to passive movement is normal.
MUSCLE SYNERGY
Describes coordinated motor action – we use synergies constantly (e.g. finger & elbow flexion combine with supination of forearm to bring food to mouth)
Operate in a normal nervous system but clinicians often use the term only in reference to pathologic synergies e.g., If when following a stroke unable to flex the shoulder without simultaneous flexion of elbow - described as flexor synergy pattern of movement