Force Output is more Variable in Patients with Peripheral Arterial Disease
Advisor Information
Sara Myers
Location
Dr. C.C. and Mabel L. Criss Library
Presentation Type
Poster
Start Date
7-3-2014 1:00 PM
End Date
7-3-2014 4:00 PM
Abstract
Peripheral arterial disease (PAD) is a vascular disease characterized by atherosclerosis in the lower extremity resulting in pain in the legs known as claudication. PAD patients have altered baseline gait including abnormal ankle moment and power [1-6]. An insufficient ability of the plantarflexors to generate force may be a key contributor. PAD patients have reduced muscular strength and power and the ankle, knee and hip, reduced cross-sectional area of muscle, reduced nerve conduction velocity, and a decrease in type II (fast-twitch) muscle fibers [6,7]. While much work has been done investigating muscular strength, little work looks beyond peak maximal muscular strength. Walking however, is not a task requiring maximal effort. Therefore, this study investigated more comprehensive variables of muscular function including average, timing, and variability measures of force profiles. Eight patients with PAD and eight age-matched controls performed isometric plantarflexion using a dynamometer. Two maximal trials of isometric plantarflexion were performed for ten seconds. PAD patients performed testing while in claudication pain. Dependent variables included peak torque, time to peak torque, average torque, and standard deviation of torque during the defined linear region. Significant differences between controls and PAD patients were discovered at peak torque, average torque during the linear region, and standard deviation of torque during the linear region. Patients with PAD were not able to generate as much maximum force during isometric plantarflexion as healthy controls. Furthermore, during the linear region, patients with PAD generated lower and more variable torque.
Force Output is more Variable in Patients with Peripheral Arterial Disease
Dr. C.C. and Mabel L. Criss Library
Peripheral arterial disease (PAD) is a vascular disease characterized by atherosclerosis in the lower extremity resulting in pain in the legs known as claudication. PAD patients have altered baseline gait including abnormal ankle moment and power [1-6]. An insufficient ability of the plantarflexors to generate force may be a key contributor. PAD patients have reduced muscular strength and power and the ankle, knee and hip, reduced cross-sectional area of muscle, reduced nerve conduction velocity, and a decrease in type II (fast-twitch) muscle fibers [6,7]. While much work has been done investigating muscular strength, little work looks beyond peak maximal muscular strength. Walking however, is not a task requiring maximal effort. Therefore, this study investigated more comprehensive variables of muscular function including average, timing, and variability measures of force profiles. Eight patients with PAD and eight age-matched controls performed isometric plantarflexion using a dynamometer. Two maximal trials of isometric plantarflexion were performed for ten seconds. PAD patients performed testing while in claudication pain. Dependent variables included peak torque, time to peak torque, average torque, and standard deviation of torque during the defined linear region. Significant differences between controls and PAD patients were discovered at peak torque, average torque during the linear region, and standard deviation of torque during the linear region. Patients with PAD were not able to generate as much maximum force during isometric plantarflexion as healthy controls. Furthermore, during the linear region, patients with PAD generated lower and more variable torque.