The CAT-CAM socket and quadrilateral socket: a comparison of energy cost during ambulation.
Twenty unilateral trans-femoral amputees fitted with either the Contoured Adducted Trochanteric-Controlled Alignment Method (CAT-CAM) socket (n = 10) or the quadrilateral (QUAD) socket (n = 10), and a "non-amputee" control group (n = 10) participated in the study. Subjects meeting the following criteria were studied: healthy males between the ages of 18 and 55 years, amputation due to non-vascular pathology, an unaffected sound limb, at least six months use of the test prosthesis, and a minimal stump length of 15 cm. Subjects ambulated in two randomized trials separated by 20 minutes of rest at 2 assigned speeds: a pace reflecting normal walking speed (97 m/min = 2.5 mph) or a slower speed (48.5 m/min = 1.25 mph). Heart rate (HR) and Oxygen uptake (VO2) measured during steady state walking were analyzed via two-way ANOVA. Differences among means were further analyzed using Tukey post hoc and simple effects tests. Significant differences were observed between the control group and CAT-CAM subjects with respect to VO2 (p < 0.05) and HR (p < 0.01) at the slower speed. The control group and subjects using the QUAD socket also differed with respect to VO2 (p < 0.01) and HR (p < 0.01) at the slower pace. Faster pace required more energy expenditure (p < 0.01) and produced higher HR (p < 0.01) than slower speeds. At faster pace, a significantly higher energy expenditure in the QUAD than the CAT-CAM group was observed (p < 0.01). It is concluded that ambulating at normal pace using the CAT-CAM socket design uses less energy than when using a QUAD socket design.
Gailey
R S
RS
Dept. of Orthopaedics and Rehabilitation, University of Miami School of Medicine, Florida.
Lawrence
D
D
Burditt
C
C
Spyropoulos
P
P
Newell
C
C
Nash
M S
MS
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000674:Amputees; D000704:Analysis of Variance; D001186:Artificial Limbs / Q000145:classification / Q000592:standards; D004526:Efficiency; D004734:Energy Metabolism; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D011474:Prosthesis Design; D016138:Walking