In this system, phosphocreatines (ATP-PC) from the muscles are broken down into ADP, a phosphate ion and energy. This is a rapid and immediate energy source for a muscle which is being heavily stressed.
Should the squat continue for several repititions, the anaerobic system can take over. While this energy source provides half the energy of the phosphagen system, it does last considerably longer. The lack of oxygen in this energy system will create the bi-product of lactic acid, which accumulates in the muscle causing a burning sensation. Similarly, the lactic acid hinders the re-supply of ATP-PC in the muscle, causing it to feel fatigued.
There is also a small amount of aerobic energy being supplied. However, as with most activities as strenuous as the squat, it is often below 5%.
The delivery of energy is a combination of the respiratory and cardiovascular …show more content…
A good example is the hamstring. If a hamstring is very flexible, the subject can squat much deeper than if his hamstring was not flexible.
Integration of the Body Systems and Functions:
A muscle contracts when it is given an electrical impulse. This impulse is given from the brain through the nervous system. Motor neurons send information to the muscle, and once it has contracted, sensory neurons receive the information. The way a muscle receives a message is through myotomes. In the squat, many myotomes are activated to deliver the specific messages to the muscles. For instance, the flexion of the hip is controlled primarily by the myotomes L1 and L2. Knee flexion is controlled by L5 to S2 and knee extension by L3 and L4.
The nerves in the lower limb associated with the squat are the femoral nerve, superior and inferior gluteal nerves, tibial nerve and the