Background: Leg length discrepancy (LLD) leads to many musculoskeletal disorders and affects daily activities such as walking. In the majority of the population, mild LLD is a common condition. Nevertheless, it is still controversy among researchers and clinicians on the effects of mild LLD during gait, and available studies have largely overlooked this issue. Objects: The purpose of the present study is to investigate the effects of mild LLD on the gait parameters and trunk acceleration. Methods: A total of 15 female and male participants with no evidence of LLD of >.5 ㎝ participated in the present study. All participants walked under the following two conditions: (1) The non-LLD condition, where the participants walked in shoes of the same heel height; (2) A mild LLD condition induced by wearing a 1.5 ㎝ higher heel on the right shoe. The GAITRite system and tri-axial accelerometer were used to measure gait parameters and trunk acceleration. To compare the variation of each variable, a paired t-test was performed. Results: Compared to the non-LLD condition, step time and swing phase were significantly increased in the mild LLD condition, while stance phase, single support phase, and double support phase significantly decreased in the short limb (p<.05). In the long limb of the mild LLD condition, single support phase significantly increased, while swing phase significantly decreased (p<.05). Furthermore, significant decrease in the gait velocity and cadence in the mild LLD condition were observed (p<.05). In the comparison between both limbs in the mild LLD condition, the step time and swing phase of the short limb significantly increased compared with the long limb, while step length, stance phase, and single support phase of the long limb significantly increased compared with the short limb (p<.05). Additionally, trunk acceleration of all directions (anterior-posterior, medial-lateral, vertical) significantly increased in the mild LLD condition (p<.05). Conclusion: The results of the present study demonstrate that mild LLD causes altered and asymmetrical gait patterns and affects the trunk, resulting in inefficient gait. Therefore, mild LLD should not be overlooked and requires adequate treatment.

It is suggested that carbohydrate metabolites may involve in the development of morula to blastocyst but many of the mechanisms are not unmasked. Two-cell stage embryos were collected and examined the effects of lactate on the development of blastocyst in vitro. The expression profiles of lactate dehydrognase (Ldh) genes and aquaporin (Aqp) genes were analyzed with RT-PCR. The successful development from morula to blastocyst was dependent on lactate concentrations. The expression profiles of Ldh genes were changed by the lactate concentration. Ldha was expressed in morula stage at 10 mM lactate, and in blastocyst stage at lactate free condition. Ldhb was expressed in morula stage at 10 mM and 20 mM lactate, and in blastocyst stage at 10 mM lactate. Aqp genes were also showed different expression patterns by the lactate concentrations. Aqp3 was expressed in hatching embryo at 120 hr post hCG administration (hph) which was cultured in BWW medium and lactate free condition. Aqp7 was expressed in hatching embryos at 120 hph which was cultured at 10 mM lactate condition. Also Aqp8 was expressed in hatching embryo at BWW and 20 mM lactate condition. Aqp9 was expressed in morula at BWW and 10 mM lactate condition, and in blastocyst at BWW. Based on these results, it is suggested that concentration of lactate in the medium and the level of lactate synthesis in embryo is critical factor for blastocoels formation. In addition it is suggested that LDH may involve the AQPs expression in embryos