Which muscle is responsible for flexing the elbow?

The biceps brachii is the muscle primarily responsible for flexing the elbow. This muscle is located in the upper arm and consists of two heads (long and short), which originate from different points on the shoulder girdle and converge into a single tendon that attaches to the radial tuberosity on the radius bone of the forearm. When the biceps brachii contracts, it pulls the forearm towards the shoulder, effectively bending the elbow joint. This action is essential for various movements and activities, such as lifting objects or performing push-ups.

In contrast, the triceps muscle is primarily responsible for extending the elbow rather than flexing it. The quadriceps, located in the thigh, plays a key role in extending the knee and is not involved in elbow movement. The deltoid muscle, which is involved in shoulder movements, does not contribute to the flexion of the elbow at all. Understanding the distinct functions and anatomical positions of these muscles is crucial for grasping how they contribute to joint movements in the body.