The relationship between energy cost and the center of gravity trajectory during sit-to-stand motion

Abstract

[Purpose] The purpose of this study was to examine the relationship between jerk cost and the formation of the center of gravity trajectory during sit-to-stand motion with asymmetrical foot placement. [Subjects] Nineteen male volunteers were included (age: 21 ± 1 years). [Methods] The subjects moved from a sitting position to a standing position under two different foot placement conditions: (1) 0 degrees of dorsiflexion on the non-dominant side and 20 degrees of dorsiflexion on the dominant side (P1) and (2) 20 degrees of plantarflexion on the non-dominant side and 20 degrees of dorsiflexion on the dominant side (P2). Two standing conditions were used: (1) natural movement and (2) instructed movement, with instructions to increase weight bearing on the non-dominant side. The center of gravity trajectory and its jerk cost were calculated at each axis: front and back (jerk-x), right and left (jerk-y), and vertical (jerk-z). [Results] Jerk-x and jerk-y were significantly larger during instructed movement than natural movement in both P1 and P2. Jerk-z was not significantly different between instructed and natural movement in P1 or P2. [Conclusion] These results indicate that energy cost influences the formation of the center of gravity trajectory during sit-to-stand motion with asymmetrical foot placement.

Motor coordination during body rotation while standing in healthy participants

“…However, Fukuda et al also reported that the relationships between motor coordination and the craniocervical and thoracolumbar joints and the thoracolumbar and pelvic joints were non-linear. Consistent with the report by Fukuda et al 13 ) , we also believe that the craniocervical joint underwent the largest angular changes while in the standing position, possibly as a motor strategy selected for minimizing energy costs 1 ) . That is, tensile force generated by muscle moment is necessary for the initial body rotation.…”

“…Movements requiring multi-joint motor coordination, such as walking, standing, and turning, occur frequently in daily life. Efficient locomotion patterns are realized as a result of multi-joint motor coordination guided by the principle of conservation of energy cost 1 ) in the execution of specific tasks, such as the forward reach 2 ) , squat 3 , 4 , 5 ) , and maintenance of a tandem stance 6 , 7 ) . In the field of physical therapy, deviations from a normal manner established for each type of movement due to disease are used to estimate the degree of dysfunction; therefore, understanding motor coordination between adjacent joints is essential for clinical reasoning.…”

Motor strategy for rapid gait initiation under conditions of limited center of pressure control

“…Forward tilt pattern was selected by all participants at AP-N and MP-N (Table 1). Previous research revealed motor pattern of activity of daily living (ADL) is taken motor pattern to minimize the energy cost7,8,9 ) . Thus, the forward tilt pattern was used the most frequently at N to minimize the energy cost by the generation of the COG-COP moments arm.…”