What Is Muscle Tension and How to Measure It?

What Is Muscle Tone and What Are Muscle Tension Assessment Methods?

Muscle tension is often described as the force created by muscle cells to pull one another. This force is often referred to as muscle tension when the person is taking a rest or in a relaxed state. It is quite important to maintain muscle tension for a healthy life. Our postures and movement depend on muscle tone.

There are some forms of muscle tension, which include static muscle tension, exercise muscle tension, and postural muscle tension. Continue reading to learn what these muscle tension forms mean.

1. Resting muscle tension

Resting muscle tension is referred to as the tension between muscles when a person is resting or lying on the bed. It varies in different conditions. The low muscle tension tone is when muscles are mushy, flabby, floppy, or lax. High muscle tension is when a person’s muscles are light, tight, or strong.

It is a misconception that muscles with low tone are weak and muscles with high tone are tough. Muscle flexibility gradually increases in low tone situation and it decreases in high tone situation. The baby with low muscle tone will not look too active as a baby with high muscle tone.

2. Postural muscle tone

The postural muscle tone is described as the stable contraction of muscles. It is necessary to hold the entire body or certain body parts in a certain posture. It is the tension between several muscles which support the skeleton to maintain the posture. Postural muscle tone changes with the changes in body posture. This tension may remain high to support easy movement and position of the body.

A person might not feel a significant muscle contraction when he stands. However, the front and back muscles contract to maintain that posture. Postural muscle tone is quite essential for better stability and movement. It won’t be possible to maintain the required posture if the postural muscle tone is too low.

3. Motor muscle tone

Motor muscle tone is described as the tension between muscles during exercises. It assures smooth and continuous movement of body parts. There won’t be spasm, tremor, or twitching due to motor muscle tone.

What Are Muscle Tension Screening Methods?

The amount of resistance to movement in muscles is called muscle tone. It ensures we can maintain the required posture. Our movement depends on the changes in muscle tone. It also dictates how fast a person can move and how he controls various movements.

Parents expect newborn children to be healthy and strong. Low muscle tone can severely affect the baby’s movements and activeness. The risks of hypotonia in newborns are quite high. Therefore, you should learn how to assess the baby’s muscle tension. You can seek immediate medical aid if the muscle tension is quite low! So, let’s reveal the way to judge muscle tension:

1. Method for babies 3 months old or younger

Put your child on the bed and lift his hands. Now, open both arms and cross them against his chest. Baby’s palms must touch his elbows. Lift your baby’s legs and position them at a 90° angle. The baby might keep his legs in that position for a while if the muscle tension is high.

Make sure the baby’s butt is on the bed when you lift his legs. Check how high you can take your baby’s legs. Do not bend the legs during this test. Now, hold the baby’s legs by his ankles and bend them to push them towards his calves. If your baby’s body resists pushing, he has a high muscle tone.

2. Method for 3 months or older babies

Hold the baby’s hands and make him sit for a while. If his head looks slightly tilted towards his back, it can be due to low muscle tension. If the baby balances his head movement, his muscle tone is high.

3. Method for 4 months old babies

A four-month-old baby is strong enough to keep his spine straight and move his limbs fast. Therefore, you should hold the baby in an upright position. Let him stand with your support and see whether the baby can balance a little bit or not.

The baby will try to imitate adults and stand on his own with little support if muscle tension is high. The baby won’t be able to balance his head or stand in the upright position if the muscle tension is too low.  Put the baby on the bed and turn him over. Let the baby rest on his stomach. If he raises his head, muscle one is high. If the baby can’t raise his head, muscle tone is low.

Parents should consult with a doctor in both high muscle tone and low muscle tone situations. It is important to provide the right treatment at the right time to prevent health issues in future.

How to Check Muscle Tension in Babies?

You can try the following techniques to check muscle tone in babies:

1. Adductor angle

The baby should be lying in the supine position on the bed. Now, the examiner will hold your newborn child’s knees to make the lower limbs straight. Once both legs are straight, the examiner will gradually pull both legs in different directions. He will stretch his legs as far as possible without hurting the child. Now, the angle between your baby’s thighs will be measured. 

2. Popliteal angle

The child will lie straight on the bed. Now, the examiner will pick one leg and bend it. That leg will be pushed towards the baby’s chest as far as possible without hurting the child. Now, the examiner will measure the angle created between the calf and thigh.

3. Heel-to-ear test

Lie down the baby on a table or a bed. Now, hold the baby’s one leg and try to bend it towards his chest. Measure the angle between the table, heel, and hip joint once the baby’s leg is bent towards his ear.

4. Foot dorsiflexion angle

Place your thumb at the bottom of the child’s feet and use other fingers to hold his heels. Now slightly bend your baby’s feet towards the calf and then calculate the angle created between the calf and foot.

5. Scarp sign

The doctor will gently hold the baby’s neck and back to create a semi-recumbent posture. Now, keep the baby’s elbow straight and then bend his hand against the tummy. Hold the baby’s fingers and pull the arm behind the other side shoulder as far as possible.

The elbow won’t cross the middle point of his chest if the baby is younger than 4months. A 5-6 months old baby’s elbow can easily cross the mid of his chest in this position.

6. Pull test

Lay the baby straight on the bed. Hold both of his hands and try to pull him forward. A newborn baby won’t be able to balance his head. Therefore, his head will hang backwards when you make him stand or sit in the upright position. The baby may also hang his head forward, so tackle his posture carefully.

It won’t be the case when the baby is 5 months old. He will bend his elbows and apply some force to resist pulling. The examiner should assess whether the baby is applying equal force from both sides or not.

What Are the Reference Values for Screening Muscle Tension?

The reference values are as follows:

Adductor angle:

• January to March: 40° to 80°
• April to June: 80° to 110°
• July to September: 100° to 140°
• October to December: 130° to 150°

Popliteal angle:

• January to March: 80° to 100°
• April to June: 90° to 120°
• July to September: 110° to 160°
• October to December: 150° to 170°

Heel-to-ear test:

• January to March: 80° to 100°
• April to June: 90° to 130°
• July to September: 120° to 150°
• October to December: 140° to 170°

Dorsiflexion angle:

• January to March: 60° to 70°
• April to June: 60° to 70°
• July to September: 60° to 70°
• October to December: 60° to 70°

How to Identify Abnormal Muscle Tone?

When making the muscle tone assessment, touch and feel the baby’s muscle for stiffness. You should feel muscle resistance and tension when bending and pulling the baby’s limbs. If the upper motor neuron is damaged, the result will show increased muscle tone. It also occurs when the child is suffering from extrapyramidal disease. Increased muscle tone should not be a concerning issue if the baby is 6 months old.  

The reduced muscle tone indicates lower motor neuron disease. The baby’s muscles will feel soft and joints may show the signs of hyperextension. Parents should consult with a specialist doctor in such conditions to improve the baby’s health.

Conclusion

We have described all the muscle tone examinations performed by specialist doctors in the hospital. These examinations take place on the day your baby is born. The doctor can also conduct these examinations several times a year to ensure the baby is fit and healthy. Thus, muscle tone examination helps the health-care specialist in assessing proper growth of the child.

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