Answer:Calcaneal tendon; his triceps surae
Step-by-step 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