Is clasp knife spasticity or rigidity?

Clasp knife rigidity describes the phenomenon in a spastic limb where, after an initial resistance to passive movement of a joint, there is a sudden reduction in tone and the limb moves quite freely through the rest of the range of the particular movement. Links: spasticity.

What is cog wheel rigidity?

Cogwheel rigidity is one of the criteria for the diagnosis of idiopathic Parkinson disease and is often an early sign of the disease. 3. Clinically, it is characterized by muscular stiffness throughout the range of passive movement in both extension and flexion.

What causes clasp knife rigidity?

Clasp-knife response refers to a Golgi tendon reflex with a rapid decrease in resistance when attempting to flex a joint, usually during a neurological examination. It is one of the characteristic responses of an upper motor neuron lesion.

Where is clasp knife rigidity?

upper motor neuron disease
clasp-knife rigidity increased tension in the extensor of a joint when it is passively flexed, giving way suddenly on exertion of further pressure; seen especially in upper motor neuron disease. Called also clasp-knife reflex.

What is the meaning of clasp knife?

Definition of clasp knife : pocketknife especially : a large one-bladed folding knife having a catch to hold the blade open.

What is muscle spasticity and rigidity?

Spasticity is stiff or rigid muscles. It may also be called unusual tightness or increased muscle tone. Reflexes (for example, a knee-jerk reflex) are stronger or exaggerated. The condition can interfere with walking, movement, speech, and many other activities of daily living.

What is the difference between spasticity and contracture?

Spasticity and contractures are conditions in which muscle imbalance across a joint leads to abnormal positioning and tightness. Spasticity refers to involuntary tightening or stiffening of muscles. The term contracture refers to abnormal positioning of a joint.

What causes spasticity?

Spasticity is generally caused by damage or disruption to the area of the brain and spinal cord that are responsible for controlling muscle and stretch reflexes. These disruptions can be due to an imbalance in the inhibitory and excitatory signals sent to the muscles, causing them to lock in place.

How do you measure spasticity?

The most common clinical assessment of spasticity in MS is as a component of the standard neurological examination. More focused clinical scales for measuring spasticity include the Ashworth Scale and the Modified Ashworth Scale, the Tardieu Scale and Modified Tardieu Scales, and the pendulum test.

Why does spasticity occur in UMN lesions?

How does UMN lesion cause spasticity and associated phenomena? The major problem is a loss of control of the spinal reflexes. Spinal reflex activity is normally tightly regulated and if inhibitory control is lost, the balance is tipped in favor of excitation, resulting in hyperexcitability of the spinal reflexes.

What is a clasp knife injury?

Clasp-knife phenomonen refers to increased muscle tone while bending or stretching a limb, whereby there is a sudden relaxation (decrease in resistance) as the muscle continues to be streched. This phenomenon has been likened to opening a clasp knife. [ from HPO]