Measuring Spasticity

The assessment of spasticity can provide information that will help in making a diagnosis of the cause of spasticity, as well as in measuring response to treatment. If a strong increase in spasticity occurs suddenly, potential causes such as a blood clot, urinary tract infection, sprain, pressure sore, or broken bone should be ruled out or treated, if necessary.

When physicians or therapists assess spasticity, they focus on three main areas: the clinical pattern of motor function, the patient’s ability to control her or his muscles, and how muscle stiffness and any contractures worsen the functional problems. Functional problems may include difficulty with bathing, toileting, eating, sleeping, dressing, sitting, transferring (such as from a chair to a bed), walking, or standing. Both the clinical history and a physical examination should evaluate the stretch reflex, passive and active motion, and function. The healthcare professional who is performing the evaluation must also distinguish spasticity from rigidity or dystonia in a muscle. Dystonia, rigidity, and spasticity cause an increased tone in muscles, but spasticity is typically only present during stretching of the muscle, and rigidity is present even when the muscle is at rest.

Because two or more muscles cross most joints, identifying the muscles affected by spasticity requires isolating the muscles. The identification can take place through clinical evaluation, that is, observing movements and palpating (feeling) the muscles, or by laboratory evaluations, such as biomechanical methods or electrophysiologic tests. The results of this testing can help the clinician to form an opinion about what muscles or activity may be working against the intended movement.