Ergometric evaluation of pathological gait

Abstract

At each step of walking, the center of gravity of the body moves up and down and accelerates and decelerates forward with a combined movement that allows an appreciable transfer (R) between gravitational potential energy and kinetic energy, as occurs in a pendulum. The positive work and power to lift the center of gravity, to accelerate it forward, and to maintain its motion in a sagittal plane, the amount of R, the maximal height reached during each step by the center of gravity, and the step length and frequency are all determined by a microcomputer a few minutes after a subject walks on a force platform. This method is applied to the analysis of pathological gait in the attempt to measure quantitatively the alteration of the normal locomotory movement of the center of gravity. The strides of the patient are compared with the strides of normal subjects; in addition, the movement of the center of gravity of the patient during the stance on the affected limb is compared with the movement of the center of gravity during the stance on the unaffected limb, thus giving an index of the asymmetry of locomotion.

Hip, Knee, and Ankle Osteoarthritis Negatively Affects Mechanical Energy Exchange

“…This study had numerous limitations. The participants walked across multiple force plates rather than a single large surface, which required a more complicated analysis, but a previous study [27] and the asymptomatic individuals in that study and in the current study provide results similar to those in other studies [4][5][6][7]13] and appear to provide valid measures of recovery in asymptomatic individuals, indicating that this method can be applied to this population. Using this method would allow for this type of analysis to be completed in many standard gait laboratories using multiple force plates rather than a single long force plate.…”

“…Considerable data exist examining energy recovery in asymptomatic young people [4][5][6][7]18] and an older population [18], and we wanted to ensure that our methods yielded results consistent with these studies before we explored energy recovery in patients with OA. In addition, the asymptomatic cohort was included to obtain a relative measure of the effect of OA in any joint and to be able to provide a reference recovery value for comparison.…”

“…The center of mass during normal walking on a relatively stiff leg follows the cycle of an inverted pendulum allowing stored gravitational potential energy of the center of mass at midstance to be converted to kinetic energy to further drive the center of mass forward and upward [4][5][6][7][13][14][15]. The efficiency of energy exchange (% recovery) between potential energy and kinetic energy can be as much as 70% during preferred-speed walking [4][5][6][7].…”

“…The efficiency of energy exchange (% recovery) between potential energy and kinetic energy can be as much as 70% during preferred-speed walking [4][5][6][7]. When energy exchange is efficient, it can reduce the amount of muscular effort needed to accelerate and decelerate the center of mass [4-7, 11, 12, 14, 15, 19].…”

“…However, the effect of OA in all three major lower extremity joints on the mechanical work of the center of mass is poorly understood. Although calculation of energy recovery is a long-standing technique that has been applied to studies of nonhuman animals and asymptomatic humans [4][5][6][7]15], only a few studies have examined gait in subjects older than 45 years and gait as affected by disorders [10,13,18], and those who have examined OA have examined the effect of knee OA on recovery [11,27]. There is little information regarding the effect of hip and ankle OA on recovery, although it can be predicted from models of energy recovery [4][5][6][7]27].…”