His lower legs are swollen due to beriberi, an illness which is caused by the lacking of vitamin B-1 (thiamine) in the diet, and his legs are most likely swollen from the illness. Beriberi was common in South East Asia due to the diets being predominantly of white rice, which has the husk of the seed removed to extend the time before it becomes inedible – except the husk contains the essential vitamin B-1.
In addition, notice the bucket of baby formula that Herzog is carrying – this is most likely the safest way and easiest way for him to get valuable nutrients that his body hasn’t been able to receive for years. It was known that some prisoners of war, if they went from their prison diet straight to normal dieting after release, they sometimes burst into cardiac arrest.
People in the image from left to right: Private 1st Class Arnold Senstrom, Sergeant Frank Duer, Private 1st Class Joseph Lewandowski, Bernard Herzog, Technician 5th Grade Bill Tksack, Technician 5th Grade Clifton Griffin, Private 1st Class John Rogen.
Santo Tomas Internment Camp was the largest of several camps in the Philippines in which the Japanese interned enemy civilians, mostly Americans, in World War II. The campus of the University of Santo Tomas in Manila was utilized for the camp which housed more than 4,000 internees from January 1942 until February 1945. The number of internees in February 1942 amounted to 3,200 Americans, 900 British (including Canadians, Australians), 40 Poles, 30 Dutch etc.
The internees were diverse: business executives, mining engineers, bankers, plantation owners, seamen, shoemakers, waiters, beachcombers, prostitutes, old timers from the Spanish-American war, 40 years earlier, missionaries, and others. Some came into the camp with their pockets full of money and numerous friends on the outside; others had only the clothes on their backs. At first, most internees believed that their imprisonment would only last a few weeks, anticipating that the United States would quickly defeat Japan. As news of the surrender of American forces at Bataan and Corregidor seeped into the camp the internees settled in for a long stay.