What is the expected muscle tone in patients with lower motor neuron lesions?

What is the expected muscle tone in patients with lower motor neuron lesions?

• A. Increased tone
• B. Normal tone
• C. Decreased tone
• D. Variable tone

Answer: (C)

In patients with lower motor neuron lesions, the expected muscle tone is decreased tone. Lower motor neurons, which include the motor neurons that originate in the spinal cord and innervate skeletal muscles, are responsible for relaying signals from the central nervous system to the muscles. When these neurons are damaged, it disrupts the transmission of signals, leading to a reduction in muscle tone. Decreased tone, commonly referred to as hypotonia, is characterized by a feeling of looseness or floppiness in the muscles. This occurs because the loss of lower motor neurons leads to reduced input to the muscles, resulting in diminished reflex activity and muscle strength. In contrast to conditions associated with upper motor neuron lesions, where tone often increases due to enhanced reflexes and muscle stiffness, lower motor neuron lesions do not retain that reflexive activity, thereby causing the muscles to relax excessively. This understanding of muscle tone in the context of lower motor neuron lesions is crucial for physical therapy practice and intervention strategies, as it guides rehabilitation approaches to improve muscle function and strength.

In patients with lower motor neuron lesions, the expected muscle tone is decreased tone. Lower motor neurons, which include the motor neurons that originate in the spinal cord and innervate skeletal muscles, are responsible for relaying signals from the central nervous system to the muscles. When these neurons are damaged, it disrupts the transmission of signals, leading to a reduction in muscle tone.

Decreased tone, commonly referred to as hypotonia, is characterized by a feeling of looseness or floppiness in the muscles. This occurs because the loss of lower motor neurons leads to reduced input to the muscles, resulting in diminished reflex activity and muscle strength. In contrast to conditions associated with upper motor neuron lesions, where tone often increases due to enhanced reflexes and muscle stiffness, lower motor neuron lesions do not retain that reflexive activity, thereby causing the muscles to relax excessively.

This understanding of muscle tone in the context of lower motor neuron lesions is crucial for physical therapy practice and intervention strategies, as it guides rehabilitation approaches to improve muscle function and strength.