- Muscles always work in pairs or else our body couldn't function the way it would right now
- Muscles will only pull (not pull), like curling a weight in a workout
- Muscles will relax while the other muscle is contracting, also like curling a weight in a workout
1. The fact that you had to make a working elbow with the given supplies.
2. Showing how it worked in the video.
3. Your muscles contract and relax. For an example, biceps and triceps are connected to tendons which are connected to the humerus, ulan, and radius bone. The tendons allow the muscles to contract and relax. Cartilage allows the bones to never rub together. Ligaments hold the bones together with the joint. This allows movements like bending your arm at the elbow.