Muscles are very important tissues in the human body. Muscle contraction is the activation of tension-generating sites within muscle cells. Muscle tone and atrophy are two terms discussed concerning the body’s muscles. However, they are different in nature. This is because muscle tone is a property of muscle, while muscle atrophy is a pathogenic situation.
The difference between muscle tone and atrophy is their nature. Muscle tone is the muscle’s resistance to passive stretch during resting state, while muscle atrophy is the wasting or thinning of muscle mass.
CONTENTS
1. Overview and Key Difference
2. What is Muscle Tone
3. What is Muscle Atrophy
4. Similarities Between Muscle Tone and Atrophy
5. Muscle Tone vs Atrophy in Tabular Form
6. Summary – Muscle Tone vs Atrophy
7. FAQ – Muscle Tone and Atrophy
What is Muscle Tone?
In physiology, muscle tone refers to the continuous and passive partial contraction of the muscles. Muscle tone helps to maintain posture and declines during Rapid Eye Movement (REM) sleep. It is typically regulated by the body’s motor neurons but can be affected by various factors such as age, disease, and nerve damage. When a sudden pull or stretch occurs in the body, it responds by automatically increasing the tension of the muscles. This reflex helps guard against danger and aids in maintaining posture.
Physical disorders can result in abnormally low or high muscle tone. Low muscle tone is known as hypotonia, while high muscle tone is known as hypertonia. Hypotonia can result from lower motor neuron diseases like poliomyelitis, whereas hypertonia can be observed in upper motor neuron diseases such as lesions in the pyramidal tract and extrapyramidal tract. Additionally, in normal individuals, muscle tone can temporarily and intermittently be lost in either flexors or extensor muscle groups, leading to muscle cramps.
What is Muscle Atrophy?
Muscle atrophy is the loss or thinning of muscle tissue. Symptoms of this condition may include reduced muscle mass, asymmetry in limb size, weakness, numbness or tingling, difficulty walking or balancing, difficulty swallowing or speaking, facial weakness, and gradual memory loss. Muscle atrophy can be caused by insufficient muscle use or by an injury or disease affecting nerves that connect to the muscles.
Muscle atrophy can be diagnosed through blood tests, muscle or nerve biopsies, electromyography (EMG), nerve conduction studies, X-rays, CT scans, and MRI scans. Treatment may involve regular exercise, improved nutrition, physical therapy, and electrical stimulation.
Similarities Between Muscle Tone and Atrophy
- Both terms relate to muscle function.
- Both can be observed through physical examination and imaging tests.
- Reduced muscle tone and muscle atrophy can be treated through physical therapies.
Difference Between Muscle Tone and Atrophy
Definition
- Muscle tone is the continuous and passive partial contraction of the muscles.
- Muscle atrophy is the loss or thinning of muscle tissue.
Triggered by
- Muscle tone is primarily triggered to maintain posture and declines during REM sleep.
- Muscle atrophy typically results from insufficient muscle use or nerve-related injury or disease.
Symptoms in Pathological Situations
- Muscle tone abnormalities may manifest as hypotonia, hypertonia, or muscle cramps.
- Muscle atrophy presents symptoms such as reduced muscle mass, limb asymmetry, weakness, numbness or tingling, difficulty walking or balancing, difficulty swallowing or speaking, facial weakness, and gradual memory loss.
Diagnosis
- Muscle tone irregularities are mainly diagnosed through physical examination and other imaging tests.
- Muscle atrophy is diagnosed through various tests, including blood tests, biopsies, and imaging scans.
Treatment
- Muscle tone abnormalities are treated through physical and occupational therapy, stimulation therapy, and botulinum toxin injections.
- Muscle atrophy is managed with regular exercise, improved nutrition, physical therapy, and electrical stimulation.
The infographic below presents the differences between muscle tone and atrophy in tabular form for side-by-side comparison.
Summary – Muscle Tone vs Atrophy
Muscle tone and atrophy are two terms related to muscle function, such as muscle contraction. However, muscle tone is an important property of muscles, while muscle atrophy is a pathologic situation. Moreover, muscle tone is the muscle’s resistance to passive stretch during resting state. Muscle atrophy is the wasting or thinning of muscle mass. So, this summarizes the difference between muscle tone and atrophy.
FAQ: Muscle Tone and Atrophy
1. What is the difference between hypotonia and normal tone?
- Muscle tone is the amount of resistance to the movement in muscles at rest. However, with hypotonia, the bicep would feel soft without any resistance. This is due to reduced muscle tone.
2. What is the difference between muscle weakness and hypotonia?
- Hypotonia refers to a decreased resting tone of the muscle and decreased resistance to passive movement, whereas muscle weakness refers to a reduction in the maximum power that can be generated against gravity.
3. What is the treatment for muscle atrophy?
- Muscle atrophy results in reduced muscle strength and an impaired ability to perform daily tasks. Muscle atrophy can be treated through regular exercise, better nutrition, physical therapy, and electrical stimulation.
4. What is the difference between atrophy and muscle wasting?
- The difference between atrophy and muscle wasting is that atrophy specifically refers to the loss or thinning of muscle tissue, whereas muscle wasting encompasses a broader concept that includes the loss of muscle mass, strength, and function.
5. What is sudden loss of muscle tone?
- The sudden loss of muscle tone refers to a rapid and unexpected decrease in the tension or contraction of muscles. This can result in a temporary loss of muscle control and may be accompanied by weakness or a feeling of limpness in the affected muscles. It can be triggered by various factors such as neurological conditions, sudden relaxation of muscles after a period of tension, or certain medical conditions.
Reference:
1. “Muscle Hypotonia – An Overview.” ScienceDirect Topics.
2. “Muscle Atrophy: Causes, Symptoms & Treatment.” Cleveland Clinic.
Image Courtesy:
1. “Man Raising His Right Arm” (CC0) via Pexels
2. “Photograph of a woman with muscular atrophy Wellcome L0074504” By Wellcome Collection gallery (CC BY 4.0) via Commons Wikimedia