Two muscles lie underneath the biceps brachii. Both heads of the biceps femoris perform knee flexion. A single muscle such as the biceps brachii contains many muscle fibers. The long head of "biceps brachii" muscle runs along this groove. By its posterior surface with the semitendinosus, semimembranosus, biceps, and gluteus maximus muscle. It is a remnant of part of Biceps femoris muscle. A muscle fiber from a biceps muscle may contain 100,000 sarcomeres. The most common injury caused by biceps curls is biceps tendon tears. The artery runs medial to the biceps tendon. A cell from the biceps brachii muscle may contain 80,000 sarcomeres. This ring is continuous with the tendon of the biceps brachii above. This also assists the biceps brachii. Injection sites include the biceps, thigh, buttocks, and stomach. There were four categories&colon; "Double Biceps", "Best Abs", "Most Muscular" and "Medley of Poses". Nahom Tsegazab was shot in the right biceps and abdomen.