why muscles work
... Muscles enable us to move. There are more than 600 muscles inthe body. The most important muscles that enable us to move include the deltoid, biceps brachii, triceps, latissimus dorsi, trapezius, pectorals, erector spin (sacrospinalis), gluteus maximus, hamstrings, quadriceps, gastrocnemius; soleus, tibialis anterior, rectus abdominus and external obliques. Muscles perform roles according to the movement required.