The antagonist muscle in a sit-up is the erector spinae muscles along the spine. These muscles work to extend the spine when you are flexing it during the sit-up exercise.
a starfish does not have a spine.
When you bend at the waist, you primarily use the muscles in your lower back (erector spinae muscles) and hamstrings. These muscles work together to support your spine and enable the bending movement. It is important to engage your core muscles as well to provide stability and protect your back.
Most of the European sports don't use percentages. Cricket, both codes of Rugby, Soccer etc etc There is only really the main American sports that use percentages at all.
Macro invertebrates are organisms with no backbone or spine that can be seen without the use of microscope. The best examples are flatworms, crayfish, snails, clams and dragonflies.
Gymnastics, Golf and Tai Chi are 3 examples!
Most of the major muscles are used. Gastrocnemius, Quadriceps, back muscles, lat dorsis, erector spine and neck muscles.
protection
They use their spine.
spine
Whether or not an animal contains a spine or backbone distinguishes animalia into two different groups: Vertebrates (with spines--examples: canines, felines, humans) and invertebrates (without spines--examples: sponges, worms, mollusks).
the bones they use are the leg the thigh and the spine.