PhysRehab Ch. 5: (Section) Examination of Motor Function Flashcards
Defined as the resistance of muscle to passive elongation or stretch. It represents a state of slight residual contraction in normally innervated, resting muscle, or steady-state contraction
Tone
(1) physical inertia
(2) intrinsic mechanical-elastic stiffness of muscle and connective tissues
(3) spinal reflex muscle contraction (tonic stretch reflexes)
Factors that influence tone
A (hypertonic) motor disorder characterized by a velocity- dependent increase in muscle tone with increased resist- ance to stretch; the larger and quicker the stretch, the stronger the resistance of the spastic muscle
Spasticity
Spasticity arises from injury to descending motor pathways from the cortex (pyramidal tracts) or brain- stem (medial and lateral vestibulospinal tracts, dorsal reticulospinal tract) producing disinhibition of spinal reflexes with hyperactive tonic stretch reflexes or a failure of reciprocal inhibition.
The result is hyperexcitability of the alpha motor neuron pool. It occurs as part of upper motor neuron (UMN) syndrome
Characterized by cyclical, spasmodic alter- nation of muscular contraction and relaxation in response to sustained stretch of a spastic muscle
Clonus
A hypertonic state characterized by constant resistance throughout ROM that is independent of the velocity of movement
Rigidity
It is associated with lesions of the basal ganglia system (extrapyramidal syndromes) and is seen in Parkinson’s disease
Rigidity
refers to a hypertonic state with superimposed ratchet-like jerkiness and is commonly seen in upper extremity movements (e.g., wrist or elbow flexion and extension) in patients with Parkinson’s disease. It may represent the presence of tremor super- imposed on rigidity.
Cogwheel rigidity
Refers to sustained contraction and posturing of the upper limbs in flexion and the lower limbs in extension. The elbows, wrists, and fingers are held in flexion with shoulders adducted tightly to the sides while the legs are held in extension, internal rotation, and plantarflexion.
Decorticate rigidity
—Decorticate rigidity is indicative of a corticospinal tract lesion at the level of diencephalon (above the superior colliculus)
Refers to sustained contraction and posturing of the trunk and limbs in a position of full extension. The elbows are extended with shoulders adducted, forearms pronated, and wrist and fingers flexed. The legs are held in stiff extension with plantarflexion
Decerebrate rigidity (abnormal extensor response)
— Decerebrate rigidity indicates a corticospinal lesion in the brainstem between the superior colliculus and vestibular nucleus
a prolonged involuntary movement disorder characterized by twisting or writhing repetitive move- ments and increased muscular tone.
Dystonia
Dystonic posturing refers to sustained abnormal postures caused by co-contraction of muscles that may last for several minutes,
UMNL Negative signs
- Paresis and paralysis
- Loss of dexterity
- Fatigue
UMNL Positive signs
- Spasticity
- Stereotyped movement synergies; spastic dystonia
- Spasms (flexor, extensor/ adductor)
- Spastic co-contraction
- Extensor plantar response (Babinski sign)
- Clonus
- Exaggerated deep tendon reflexes (DTR)
- Associated reactions
- Disturbances in movement efficiency and speed; mass movements
Dystonia results from a CNS lesion commonly in the basal ganglia and can be…
inherited (primary idiopathic dystonia), associated with neu- rodegenerative disorders (Wilson’s disease, Parkinson’s disease on excessive l-dopa therapy), or
metabolic disor- ders (amino acid or lipid disorders).
Dystonia can affect…
…only one part of the body (focal dystonia) as seen in spasmodic torticollis (wry neck) or isolated writer’s cramp.
… Segmental dystonia affects two or more adjacent areas (e.g., torticollis and dystonic posturing of the arm)
