Sports schools, colleges, gym trainers, and physicians often advise people to do resistant workouts for each major group of muscles. Identifying major muscles in the body and what functions they perform could be highly beneficial for you, especially if you are a newbie in any physical training program as it can help you build your shape more effectively. Within this article we’ll be answering the questions: ‘What are the major muscles of the body and their function’.

What are the Major Muscles of the Body and their Function?

According to Deborah Bull, a fitness trainer at Olympia gym, NY city, “It is not about weight, it’s about fitness, and one component of being fit is to have stronger muscles, because fat is not very efficient, where the muscle is”.

Our body consists of 640+ muscles that together make up roughly 50% of our body weight. Muscles are needed for vital functions of the body, i.e. from locomotion to speech, from vision to hearing and from circulating blood to urination etc. The existence of life without muscles is nearly impossible. Every muscle or group of muscles is a discrete organ designed to perform a specific function in the body.

Major muscles of the body and their functions

Anatomically; according to the difference in their structure, muscles are divided into three different types viz skeletal muscles (locomotion, movements, reflex responses, fight & defence etc.), smooth muscles (food absorption, respiration, vision, urination etc.) and cardiac muscles (pumping of blood). Physiologically even the same type of structural muscles can perform diverse functions, e.g. despite the same type of skeletal muscles, biceps are responsible for flexion of the arm while the contraction of triceps causes extension.

If you’ve researched muscles before you’re probably familiar with the skeletal muscles. The skeletal muscles are the major players whilst exercising; however, the normal function of the other two types of muscles is also important. Actually, all the muscles of the bodywork in great coordination. Running, for example, uses all the muscles of the body:

  • Skeletal muscles for motion
  • Cardiac muscles to pump extra blood to skeletal muscles
  • Smooth muscles of viscera’s to meet the excess nutritional demand to overworking muscles of the body

However, when training and developing fitness programs, we concentrate on the skeletal muscles. Below you will find a brief description of the major skeletal muscles involved in physical activity or a heavy workout.

Biceps and triceps

These are the front and back muscles of the arm. Biceps cause flexion of the forearm (bending or curling towards shoulder) while triceps causes extension of the forearm (moving forearm away from shoulder)

Rotator cuff and deltoid

These are the major muscles of the shoulder. Deltoid is responsible for the abduction and flexion of the shoulder (lift and move the arms). A rotator cuff is a group of four muscles that often act simultaneously with similar functions. They cause rotation of the shoulder joint and provide stability and strength.

Chest, core and back

Chest comprises two prominent muscles; pectoralis major and pectoralis minor. Both muscles function to generate force for pushing objects away from the body e.g. hitting the tennis ball.

Main muscles of the core include; rectus abdominis (6 pack muscle) and obliques. They provide stability to internal organs during inspiration and expiration and causes later flexion of the spine.

Back muscles include the main muscle; latissimus dorsi and others (teres major, trapezius and rhomboids), all involved in retraction and pulling e.g. pulling on a rope in the tug of war.

Thighs and legs

Thighs and legs contain an opposing group of muscles. Anterior group of thigh muscles called quadriceps causes extension of leg while a posterior group called hamstrings causes flexion of the leg. In a similar manner, anterior muscles of the leg include tibialis muscles (tibialis anterior and tibialis posterior) which cause dorsiflexion while at the posterior of the leg are triceps surae (gastrocnemius and soleus) both of which function to plantarflex the leg.