Bilateral

Bilateral refers to the "both sides." Bilateral is a term used to describe movements or structures that occur on both sides of the body. For example, the external obliques contract bilaterally (on both sides) when assisting in spinal flexion.

For more examples of bilateral used in anatomy (including a video lecture), check out:

• Lesson 1: Anatomical Position and Anatomical Directions
• Lesson 3: Joint Actions
• Lesson 18: The Spine and Trunk Muscles

Terms referring to sides:

• Bilateral
• Unilateral
• Contralateral
• Ipsilateral

Examples of uses of the term "bilateral"

• Joint Actions and Muscles: Most muscles in the human body are paired, occurring on both sides. When they contract unilaterally or bilaterally, muscles may contribute to different joint actions. For example, the erector spinae contribute to spine extension when they contract bilaterally but to ipsilateral flexion or ipsilateral rotation when they contract unilaterally.
• Exercise science: Many exercises require bilateral contributions from both arms, both legs, or both sides. For example, during a bench press , the arms work bilaterally. Squats are a bilateral motion requiring both legs. Suspension rows can be performed bilaterally (with two arms) or unilaterally with one arm.