Muscle Tone:

Muscle tone or rigid muscles, also called hypertonia or spasticity: Increased muscle tone — occurring in conditions with impaired variable motor timing (ADHD, dyspraxia) — can interfere with walking, movement, and speech. Causes are spasticity (abnormal muscle stiffness), unusual tightness, chronic motor disorders, neurological conditions, stress, pain, body position. Amount of muscle tone depends on speed of movement: faster movements result in greater resistance and vice versa. Reflexes (knee-jerk reflex) are stronger or exaggerated.