Vacuum Forming

Vacuum Forming

Ben Wilson 

In an article I wrote in 1974 on vacuum forming of sheet plastics I erred in stating that the first reference to vacuum forming of sheet plastics in orthotics and prosthetics was a paper by Gordon Yates in 1968. I should have remembered that Dana Street presented this concept in Volume 1 of the Orthopedic Appliances Atlas for the fabrication of cervical orthoses. This is certainly an excellent example of how long it takes to get a technological development from the idea stage to fairly widespread application.

Fig. 1 Vacuum-forming a shank for a below-knee prosthesis using the hand-drape.

In the time since my article was published in "Orthotics and Prosthetics" vacuum forming of sheet plastics has been used more and more by private practitioners in both orthotics and prosthetics.

Although the educational programs, with a few exceptions, seem to have been very slow in teaching vacuum forming techniques, use of the technique seems to be expanding, owing in part to the several workshops sponsored by the American Academy of Orthotists and Prosthetists.

Every process and system has its limitations, and we all recognize that each design in orthotics and prosthetics represents a compromise, but as time goes on the gaps that engender compromise are narrowed as experience is gained.

Although the "Orthotics and Prosthetics Clinic Newsletter" has discussed several aspects of vacuum forming in the relatively recent past, in view of what seems to be a rapidly expanding program it seems appropriate that another survey be made concerning the uses of and problems encountered by the private practitioners.

A questionnaire on this subject is included in this issue. It will be appreciated greatly if each recipient will complete the enclosed form and add any comments he or she feels that will be helpful in improving service to patients.

Fig. 2. Vacuum-forming thigh section of knee-ankle-foot prosthesis using automatic machinery.

Fig. 3. Vacuum-forming a below-knee socket with use of a platen and form for holding plastic sheet.

References:

1. "Vacuum-Forming of Plastics in Prosthetics and Orthotics," A. Bennett Wilson, Jr., Orthotics and Prosthetics, Vol. 28, No. 1, March 1974.
2. "A Method for the Provision of Lighweight Aesthetic Orthopedic Appliances," Gordon Yates, Orthopaedics, 1:2:153-162, 1968.
3. "Plastic Braces," Dana M. Street; pp. 90-95 in Orthopaedic Appliances Atlas, Edwards Brothers, Ann Arbor, Michigan, 195.

Additional Bibliography:

1. "Fabrication and Application of Transparent Polycarbonate Sockets," Vert Mooney, M.D., Roy Snelson, Orthotics and Prosthetics, Vol. 26, No. 1, March 1972.

2. "Fabrication of Vacuum-Formed Sockets for Limb Prostheses," Roy Snelson, Orthotics and Prosthetics, Vol. 27, No. 3, September 1973.

3. "Report of Workshop on Below-Knee and Above-Knee Prostheses," Hector Kay, June D. Newman, Orthotics and Prosthetics, Vol. 27, No. 4, December 1973.

4. "The Use of Check Sockets in Lower-Limb Prosthetics," Samuel Hammontree, Roy Snelson, Orthotics and Prosthetics, Vol. 27, No. 4, December 1973.

5. "A Thermoplastic Structural and Alignment System for Below-Knee Prostheses," Hans Richard Lehneis, Orthotics and Prosthetics, Vol. 28, No. 4, December 1974.

6. "Development of a Thermoplastic Below-Knee Prosthesis With Quick Disconnect Feature," Charles H. Pritham, Orthotics and Prosthetics, Vol. 28, No. 4, December 1974.

7. "Vacuum-Formed Sockets in Prosthetics Education," Bernard C. Simons, Alan V. Dralle, Orthotics and Prosthetics, Vol. 29, No. 2, June 1975.

8. "Ultralight Prostheses for Below-Knee Amputees," A. Bennett Wilson Jr., Melvin L. Stills, Orthotics and Prosthetics, Vol. 30, No. 1, March 1976.

9. "Use of Thermoplastic Components in Temporary Prostheses," Charles H. Pritham, Ivan E. Letner, David Knighton, Orthotics and Prosthetics, Vol. 30, No. 4, December 1976.

10. "Applications of Transparent Sockets," S.I. Reger, I.E. Letner, CH. H. Pritham, M.D. Schell, and W.G. Stamp, Orthotics and Prosthetics, Vol. 30, No. 4, December 1976.

11. "Above-Knee Polypropylene Pelvic Joint and Band," Erich Fischer, Orthotics and Prosthetics, Vol. 30, No. 4, December 1976.

12. "A Lightweight Above-Knee Prosthesis with an Adjustable Socket," George Irons, Vert Mooney, Sandra Putnam, Michael Quigley, Orthotics and Prosthetics, Vol. 31, No. 1, March 1977.

13. "Welding Plastics," Neil R. Donaldson, Michael J. Quigley, Orthotics and Prosthetics, Vol. 31, No. 1, March 1977.

14. "Functional Partial-Foot Prosthesis," Gustav Rubin, Michael Danisi, Bulletin of Prosthetics Research, BPR 10-16, Fall 1977.

15. "A Functional Chopart Prosthesis," Gustav Rubin, Michael Danisi, Inter-Clinic Information Bulletin, Vol. 11, No. 6, March 1972.

16. "Vacuum-Forming Techniques & Materials in Prosthetics & Orthotics," Alex Artamonov, Inter-Clinic Information Bulletin, Vol. 11, No. 10, July 1972.

17. "A Foot Amputation Orthosis-Prosthesis," H.J. Ruben-stein, G.J. Sweeney, P. Strong, G. Durrett, Inter-Clinic Information Bulletin, Vol. 14, No. 4, April 1975.

18. "Partial Foot Amputation-A Case Study," Charles H. Pritham, Newsletter. . . Prosthetics and Orthotics Clinics, Vol. 1, No. 3, Summer 1977.

19. Manual for an Ultralight Below-Knee Prosthesis, A. Bennett Wilson, Jr., Charles H. Pritham, Melvin L. Stills, Rehabilitation Engineering Center, Moss Rehabilitation Hospital-Temple University-Drexel University (1977).

20. The Rancho Ultralight Below-Knee Prosthesis, Michael Quigley, George Irons, Neal Donaldson, Rehabilitation Engineering Center, Rancho Los Amigos Hospital County of Los Angeles, University of Southern California (1977).