Dr. Jacob Lowe, a Boston physician, is credited with inventing the shoe-fitting fluoroscope in the aftermath of World War I. Initially developed to diagnose foot problems in veterans, Lowe adapted the device for commercial use in shoe stores, filing a patent application in 1919 that was granted in 192712. The technology quickly gained popularity, with Milwaukee emerging as a center for production. By the early 1950s, an estimated 10,000 machines were operating in the United States, 3,000 in the United Kingdom, and 1,000 in Canada3. The devices capitalized on several social trends, including:

• Public fascination with X-rays and radium

• The "scientific motherhood" movement encouraging women to incorporate scientific innovations into childcare

• Increasing focus on children as advertising targets

Marketed as a modern, infallible method for ensuring proper shoe fit, the fluoroscopes became a powerful tool for attracting customers, particularly families with children2.

Typically standing about 4 feet (1.2 m) tall, these wooden cabinets housed an X-ray tube in the base and featured a slot for customers to insert their feet1. Three viewing portholes allowed the customer, salesperson, and a third party to simultaneously observe the X-ray image displayed on a fluorescent screen2. The machines generally employed a 50 kV X-ray tube operating at 3 to 8 milliamps3. Customers could wiggle their toes to assess shoe fit, with the bones of their feet and shoe outlines clearly visible1. Despite their popularity, the fluoroscopes provided only a one-dimensional view from above, limiting their effectiveness in accurately determining proper fit4.

Exposure to radiation from shoe-fitting fluoroscopes posed significant health risks to both customers and store employees. Measurements indicated that doses to feet ranged from 7 to 14 R for a 20-second exposure, while exposure rates at the position of the feet could reach 16 to 75 R/min1. Whole-body doses for salespeople were estimated at up to 95 mr/week, with average annual effective doses of 3.7 mSv2. Potential health effects included:

• Skin and bone marrow damage

• Growth problems in children

• Increased cancer risk, especially with chronic exposure

• Dermatitis and radiation burns

Several cases of serious injuries were documented, including a shoe model whose leg required amputation due to severe radiation burns1. Despite these risks, no injuries to customers were reported, likely due to the long latency period between exposure and cancer development2.

Growing awareness of radiation hazards led to increased scrutiny and regulation of shoe-fitting fluoroscopes in the 1950s. Milwaukee became one of the first cities to regulate these machines in 1950, while Pennsylvania took the lead in banning them outright in 19571. By 1960, 34 states had prohibited their use1. The decline of these devices was not solely due to regulations, however. As public knowledge about radiation risks increased, the marketing appeal of the fluoroscopes diminished, with well-informed customers becoming wary of the technology1. By the 1970s, shoe-fitting fluoroscopes had largely disappeared from retail stores, marking the end of an era in which radiation exposure was casually integrated into everyday commercial activities23.