The muscle type responsible for body movements is skeletal muscle. This type of muscle is under voluntary control (unlike cardiac and smooth muscle) meaning that we can consciously control the movements we make.
The specific skeletal muscle responsible for movement will depend on what movement is being made.
From what I understand there is a muscle identified as the Psoas muscle that is centered within the lower mid portion of the body.
all skeletal muscles
It is the Rubrospinal Tract. It's main role is the mediation of voluntary movement. It is responsible for large muscle moments such as the arms and legs as well as fine muscle movement.
The motor neurons are responsible in skeletal muscle movement.
The muscle that is responsible for most of a movement is called a prime mover. It may also be called an agonist.
Smooth muscle is responsible for involuntary movement, just like skeletal muscle, only the movement is usually in the internal organs.
An Agonist
the muscle would be the flexor muscle because it contracts
the prime mover is the muscle responsible for most of the movement in a group of muscles; called the chief muscle.
The muscle that is responsible for the movement of the head from left to right.
Skeletal or voluntary muscle is capable of rapid contraction and is responsible for skeletal movement.
cerebellum
Normal skeleton muscle is responsible for all voluntary movement and The Cardiac muscle is the muscle of the heart.
smooth muscle