Kinematic analysis of treadmill walking in healthy adults according to physical performance

Introduction Modified joint range of motion (ROM) and spatio-temporal gait parameters in elderly or obese healthy subjects have been found. Authors have hypothesized that these alterations may be due to a reduction in physical performance, especially for strength and flexibility (Daley, 2000; Wearing, 2006; Wert, 2010), but quantitative studies measuring the influence of physical performance on gait pattern are scanty. The aim of this study was to analyse the kinematics of treadmill walking of healthy adults to understand if strength and flexibility could affect gait parameters. Methods 20 healthy adults (age, 26.9±4.7 yr; BMI, 22±1.9 kg/m2; iMVC, 1458±458 N; Flexibility, 34.8±13.6 cm; PWS, 5.5±0.5 km/h) were recruited in the study. Isometric maximal voluntary contraction (iMVC) was measured by two force plates (Twin Plates, Globus, Italy) which were fixed onto the foot platform of a horizontal leg press (Technogym SpA, Gambettola, Italy). Flexibility was assessed by the V-sit and reach test. The preferred walking speed (PWS) was determined on a 50-m section of athletics track. A kinematic analysis was performed with an optoelectronic system (SMART-E, BTS, Italy) during a 10-min bout of treadmill walking at 5.5 km/h. The following parameters were computed: step length and width (m), step frequency (step/min), stance and swing phase durations (% cycle), double support time (% cycle), hip and knee extension (°) and hip and knee ROM (°). Results Significant associations, adjusted for age, height and weight, were identified between iMVC and step width (r=0.501, F=6.04, p=0.024), stance (r=0.537) and swing (r=-0.537) phase durations (F=7.28, p=0.015), double support time (r=0.639, F=12.43, p=0.002), and between Flexibility and step length (r=-0.547, F=7.68, p=0.013). Discussion Our data indicate that lower limb maximal strength and hamstring flexibility influence step length and width, stance and swing phase durations and double support time of treadmill walking, suggesting the necessity to attain and maintain adequate levels of both strength and flexibility even in a healthy adult population. References Daley MJ and Spinks WL. Sports Med. 2000;29:1-12. Wearing SC et al. Obes Rev. 2006;7:13-24. Wert DM et al. Phys Ther. 2010;90:977-85.