Lihastoonus

Lihastoonus, also known as muscle tone or muscle tonus, refers to the continuous and passive partial contraction of the muscles, which helps maintain posture and readiness for movement. It is a fundamental aspect of the musculoskeletal system, contributing to the stability and support of joints and bodily positions without conscious effort.

Muscle tone is regulated by the nervous system, particularly by the stretch reflexes mediated through sensory receptors within the muscles. This ongoing activity enables muscles to respond swiftly to changes in posture or movement, allowing for coordination and balance. Normal muscle tone is essential for everyday activities such as standing, walking, and maintaining equilibrium.

There are variations in muscle tone across individuals and within different muscle groups, often described as high, normal, or low. Hypertonia refers to abnormally increased muscle tone, which may cause stiffness and restrict movement, commonly observed in conditions such as spastic cerebral palsy or multiple sclerosis. Conversely, hypotonia indicates decreased muscle tone, resulting in floppiness and reduced strength, and may be associated with disorders like muscular dystrophy or certain neurological conditions.

Assessment of muscle tone is an important aspect of neurological and physical examinations, aiding in diagnosing various musculoskeletal and neurological disorders. Interventions to modify muscle tone include physical therapy, pharmacological treatments, and in some cases, surgical procedures.

Overall, lihastoonus plays a critical role in motor control and postural stability, serving as a fundamental component of neuromuscular function in humans.