A comparison of trans-tibial amputee suction and vacuum socket conditions.
Daily volume loss of the stump leads to a poor fit of the prosthetic socket. A method of preventing this volume loss and maintaining a good fit was developed. A vacuum (-78 kPa) was drawn on the expulsion port of a total surface-bearing suction socket to hold the liner tightly against the socket. Stump volume of 10 trans-tibial amputees was measured prior to and immediately after a 30 minute walk with normal and vacuum socket conditions. Under the normal condition, the limb lost an average of 6.5% of its volume during the walk. In contrast, with the liner held tightly by vacuum, the limb gained an average of 3.7% in volume. It is believed that the difference observed between conditions resulted from a greater negative pressure developed during the swing phase of gait with the vacuum condition. X-rays revealed that the limb and tibia pistoned 4 mm and 7 mm less, respectively, under the vacuum condition. The combination of reduced pistoning and maintenance of volume is thought to account for the more symmetrical gait observed with the vacuum.
Board
W J
WJ
Department of Health, Physical Education and Sports Science, Saint Cloud State University, Minnesota 56301-4498, USA.
Street
G M
GM
Caspers
C
C
D000328:Adult; D000672:Amputation Stumps; D000674:Amputees / Q000534:rehabilitation*; D001186:Artificial Limbs; D001696:Biomechanical Phenomena; D015992:Body Mass Index; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D017755:Prosthesis Fitting; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D013977:Tibia / Q000601:surgery; D014618:Vacuum