Flexion
This is the Joint Movements section about the types of movements between bones at joints in the body.
The expressions listed in this category could also be described as:
- actions at joints
- actions of muscles, or
- muscle actions
For a single list of all the movements of the body included in this section see types of movements at joints.
Short definition of Flexion:
Flexion is movement decreasing the angle between articulating bones. Some texts express this as 'decreasing the inner angle of the joint'.
For example, plantarflexion is the bending of the toes (or fingers) towards the sole (or palm).
The opposite movement to flexion is extension.
It is useful to know words related to flexion, including:
- dorsiflexion - which is backward flexion or bending, e.g. of the hand or foot.
- plantaflexion - which is forwards flexion or bending, e.g. of the hand or foot.
- lateral flexion - i.e. bending to the side (left side, or right side) e.g. of the neck or torso.
- flexor - a muscle that can act to cause a flexion movement at a joint is called an flexor.
- to flex (verb) - e.g. athletes flex and extend their muscles.
Example of Flexion:
The above video clip (no sound) demonstrates hip flexor exercises.
The person flexes his hip joint by moving his right leg towards his torso, i.e. decreasing the angle between his upper-body and his right femur. This exercise is repeated several times. The flexion part of the exercise is the movement of his knee towards his chest. After each time this has been done he then has to extend his hip, i.e. move his right knee, lower leg and foot away from his chest - in order to be able to repeat the exercise by then flexing his hip again by repeating the movement of his knee, lower-leg and foot back towards his chest (decreasing the angle between his chest and upper-leg).
The above video clip (no sound) demonstrates hip flexor exercises.
The person flexes his hip joint by moving his right leg towards his torso, i.e. decreasing the angle between his upper-body and his right femur. This exercise is repeated several times. The flexion part of the exercise is the movement of his knee towards his chest. After each time this has been done he then has to extend his hip, i.e. move his right knee, lower leg and foot away from his chest - in order to be able to repeat the exercise by then flexing his hip again by repeating the movement of his knee, lower-leg and foot back towards his chest (decreasing the angle between his chest and upper-leg).
See also list of definitions of muscle terminology (words used to convey information about specific muscles) - useful for studying human anatomy and physiology, sports sciences e.g. physical education (PE), physiotherapy, and other health sciences.
About this section:
This is the Joint Movements section, which is about the types of movements between bones at joints in the body. Alternatively, terms listed in this category could be described as:
- actions at joints,
- actions of muscles or
- muscle actions.
For a single list summarizing all the movements of the body included in this section see
types of movements at joints.
See also definitions of muscle terminology (words used to convey information about specific muscles) - useful for studying human anatomy and physiology, sports sciences e.g. physical education (PE), physiotherapy, and other health sciences.
