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[Purpose] This study examined the kinematic and kinetic characteristics of one-leg standing (OLS) of subjects with functional ankle instability (FAI). [Subjects] The study group consisted of 11 patients (9 males, 2 females) with FAI only on one side. [Methods] The subjects transitioned to the OLS stance after taking a side step towards either (the affected or unaffected) side. The kinematic and kinetic data of the body segments were collected using a motion analysis system and two force plates. [Results] A comparison of the measurements showed that the integral value of the internal hip abduction moment (IHM) of the following limb, the integral value of the IHM of the leading limb, angular displacement of the hip and trunk during OLS, the angular velocities of the trunk and hip during OLS were greater on the affected side than on the unaffected side during OLS, and the absolute value of the minimum value of the ground reaction force in the medial-lateral direction (Fx) on the leading limb was greater on the affected side than on the unaffected side during OLS. Furthermore, the motion time was significantly prolonged on the affected side than on the unaffected side during OLS. [Conclusion] These results suggest that the following limb is used to control the center of mass during OLS to avoid force on the affected side. To compensate, subjects performed postural control dependent on the trunk and hip movements; thus, the complete motion required more time on the affected side. [ABSTRACT FROM AUTHOR]

[Purpose] The purpose of this study was to identify the most appropriate location of an accelerometer used for gait analysis. [Subjects] Fifteen healthy male volunteers participated in this study. [Methods] The trunk acceleration and ground reaction force (GRF) during normal walking were measured using accelerometers attached at the level of the tenth thoracic vertebrae (Th10), third lumbar vertebrae (L3) and second sacral vertebrae (S2). Cross-correlation coefficient (CC) were used to determine how reasonable GRF values estimated using accelerometers on the trunk were. The CCs of GRFs in the vertical (VT), anterior-posterior (AP) and mediolateral (MR) directions were compared between the 3 locations. [Results] The CCs in the VT and AP directions at L3 were significantly higher than those at the other 2 locations. However, the CC in the ML direction was low in all locations. [Conclusion] The pattern of trunk acceleration at the level of L3 was similar to that of GRF. [ABSTRACT FROM AUTHOR]

[Purpose] The aim of this study was to clarify the characteristics of external knee adduction moment of knee osteoarthritis (KOA) sufferers using principal component analysis. [Subjects] The subjects were 19 limbs of 10 women with KOA and 10 limbs of 10 middle-aged women without knee joint pain. [Method] The movement task was gait initiation, and we calculated the external knee adduction moment of the stance limb using a 3D motion analysis system and a force plate. Then, we performed a between group comparison of the principal components obtained by principal component analysis of the temporal changes in external knee adduction moment during gait initiation. [Results] In the between group comparison of the first three principal components, we found a significant difference between the KOA group and the controls only for the first principal component. [Conclusion] In this study, we revealed that the external knee adduction moment of KOA sufferers is consistently large from the start of gait initiation. Accordingly, it is necessary to consider the status of lower limb alignment during standing, as it is one of the factors influencing the magnitude of external knee adduction moment of KOA patients. [ABSTRACT FROM AUTHOR]

[Purpose] The purpose of this study was to compare external knee adduction moment of gait initiation and steady-state gait in people with knee osteoarthritis and normal adults. [Subjects and Methods] Ten females with severe bilateral knee osteoarthritis (KOA) and 9 female healthy adults (HA) performed gait initiation and steady-state gait. External knee adduction moment of the stance limb was measured using 3D motion analysis and force plates. [Results] The results show only a main effect of group, not a main effect of task. [Conclusion] External knee adduction moment was similar between gait initiation and steady-state gait. [ABSTRACT FROM AUTHOR]

[Purpose] The purpose of this study was to investigate if the use of a headsupport and inclination angle of the head and neck would influence the shear force on the buttocks in a comfortable chair sitting posture. [Methods] Thirteen healthy males, mean age 21.2 ± 0.9 years, without any pathologies in the leg and/or trunk participated in this study. Experiments were conducted under six conditions, i.e. head extension angle 0 degrees, 20 degrees, and 40 degrees with or without a headsupport. The shear force on the buttocks was measured using a force plate. For statistical analysis, a two-factor factorial ANOVA was used with the level of significance set at p<0.05. [Results] The shear force increased as inclination angle of the head and neck increased without a headsupport, but it did not change much with a headsupport. There was a significant interactive effect between with or without the headsupport and the inclination angle of the head and neck on the shear force on the buttocks (p=0.012). [Conclusion] The results suggest that level of shear force applied to the buttocks depends on whether the patient is sitting on a chair with or without a headsupport, and that use of a headsupport is effective for decreasing the shear force on the buttocks. [ABSTRACT FROM AUTHOR]

Sit-to-walk (STW) motion is a series of motions in which subjects stand up from chair and initiate gait. We researched the relationships between the STW motion and the muscle strength of the knee (extension / flexion), balance tests, and fall experiences of elderly people living at home. The subjects were 18 men (mean age 73.9 ±5.3 years). The subjects were instructed to perform STW motion as fast as possible. Balance tests were evaluated with the Timed Up and Go test (TUG test), functional reach test, and maximal step length. In the results, some relationships were confirmed between the biomechanical characteristics of STW and muscle strength or balance tests. Subjects who spent longer performing the TUG test and who had fall experiences rose until they were standing almost upright before initiating gait. [ABSTRACT FROM AUTHOR]