More formally, chiroplasty, or cheiroplasty, is a term which refers to plastic surgery of the hands. The term combines root word chir(o), which means hand, and the suffix -plasty, which means surgical repair.
(How Do Your Muscles Work continued) Thousands of thin spaghetti-like fibers make up muscle tissue. These fibers receive messages from the brain, causing the fibers to contract. The main muscles at work in cycling are the quadriceps and hamstrings in the upper leg, and the gastrocnemius and soleus in the calf. These muscles contract in a sequence that creates the pedaling action. The quadriceps and hamstrings do most of the work when you ride a bicycle.
Legs Play a Big Part. Your legs are heavily relied on in bicycling, for the action of pushing the pedals to power the bike. The quadriceps at the front of your thighs and the hamstrings at back are the primary muscles in your lower body used during cycling, but the gastrocnemius and smaller soleus muscles in your calves are also utilized.