Final answer:
The bicep tendon in the bicipital groove is held in place by the tendon sheath and the transverse humeral ligament, all of which allow the biceps brachii muscle to facilitate forearm movement.
Step-by-step explanation:
The structure that holds the bicep tendon in the bicipital groove is a combination of the tendon sheath and the transverse humeral ligament. The bicipital groove, also known as the intertubercular groove, is a narrow groove located between the greater and lesser tubercles of the humerus. The articular capsule, along with the tendon of the biceps brachii muscle's long head, play a critical role in maintaining the position of the tendon within this groove.
The biceps brachii muscle, which has tendons connecting to the upper arm and the forearm, allows for the movement of the skeleton by facilitating the flexing of the forearm. The brachialis and brachioradialis muscles, located on either side of the tendon, also contribute to this function. Collectively, these elements ensure the stable and efficient operation of the arm during various motions.