A heavyset middle-aged insurance salesman who doesn't exercise often accepts his friend's invitation to a pickup basketball game. When attempting a jump shot, he falls to the ground in pain, grasping at the calf of his leg. There is an enormous bulge in his leg immediately below the knee, and he is unable to plantar flex that foot. Most likely he has injured his ___ and the bulge is ___.

Calcaneal tendon; his triceps surae

Explanation:

The Calcaneal tendon which is also called Achilles tendon is the thickest  tendon located at the back of the leg that  attaches the plantaris,calf and soleus muscles to the calcaneal bone. These muscles acting together at the tendon is responsible for plantar flexion of the foot of the ankle

The triceps surae on the other hand  consisting of two muscles forms the main mass of the calf which are the gastrocnemius and the soleus which join their tendons of  into the midline of the leg into one tendon by inserting at the calcaneal tendon are responsble for providing flexion of the leg

Therefore, the heavyset man who falls to the ground in pain, grasping at the calf of his leg and having an enormous bulge in his leg immediately below the knee, with the inability  to plantar flex his foot must have injured his _Calcaneal tendon__ and the bulge is _triceps surae because those are the site for these tendon and muscle