Gymnastics 4 Hire ≡

How Muscles Work

This article is targeted at a young audience. It is not meant to be scientific. It is a simplistic overview, and terminology and language is aimed at a young audience.

Muscle crosssection

A muscle contains a whole lot of little fibres, kind of like how a rope is made up of a lot of little strands.

When you use (contract) your muscles, these little fibres all get shorter.

You can only make a muscle shorter (contract). Once you have made it short, you need to use a muscle on the other side to pull it back out. Muscles work together.

Strength is the maximum mass a muscle can pull.

Endurance is how long a muscle can pull less than its maximum mass.

Power is how fast the muscle can pull its maximum mass.

Flexibility is how long a muscle can become without breaking.

Increasing Flexibility...

As we get stronger, the muscle fibres get fatter and shorter. Because the muscle fibres get shorter, the muscle can’t stretch as far.

To make the muscle be able to stretch out longer, we need to make the muscle fibres longer. The way we do this is by "breaking" the fibre. Your body then repairs the fibre, but makes it longer at the same time.

So, to get more flexible you need to do a little bit of damage to your muscles. This means that stretching will need to be uncomfortable.

Some Muscle Names

Front (Anterior)

  1. Sternocleidomastoid - rotate or bow the head. (prayer muscles)
  2. Trapezius
  3. Deltoid - the prime mover of arm abduction.
  4. Pectoralis - adduct and flex the arm.
  5. Biceps brachii - the prime mover for forearm flexion and supination.
  6. Brachialis
  7. Brachioradialis
  8. Flexor carpi radialis - flex the wrist and abduct the hand.
  9. Palmmaris longus
  10. Flexor digitorum superficialis - flex the wrist and abduct the hand.
  11. Gluteus medius
  12. Sartorius - the synergist to bring about the cross-legged position.
  13. Rectus femoris - produces the kicking motion of the knee.
  14. Vastus medialis - flex and invert the foot.
  15. Peroneus longus
  16. Tibialis anterior - flex and invert the foot.
  17. Soleus
  18. Gastrocnemius - the prime mover for pointing the toes. (toe-dancer's muscle)
  19. Vastus lateralis
  20. Gracilis
  21. Adductor longus
  22. Tensor fasciae latae
  23. Rectus abdominis
  24. External abdominal oblique
  25. Serratus anterior
  26. Orbicularis oris - close the mouth and protrude the lips. (kissing muscle)
  27. Orbicularis oculi - close the eyes, squint, and blink.
  28. Occipitofrontalis - raise the eyebrows and wrinkle the forehead.

Back (Posterior)

  1. Sterncleidomastoid - rotate or bow the head. (prayer muscles)
  2. Trapezius
  3. Deltoid - the prime mover of arm abduction.
  4. Infraspintus
  5. Teres major
  6. Triceps brachii
  7. Brachioradialis
  8. Extensor carpi radialis
  9. Extensor digitorum
  10. Extensor digiti minimi
  11. Extensor carpi ulnaris
  12. Gluteus maximus
  13. Biceps femoris
  14. Semitendinosus
  15. Gracilis
  16. Semimembranosus
  17. Gastrocnemius
  18. Soleus
  19. Fascia lata
  20. Vastus lateralis
  21. Thoracolumbar fascia
  22. Latissimus dorsi


Author: Gary Black, 30-Aug-2015