This study aimed to explore turning characteristics in healthy young adults with a focus on differences in sex and the effects on body coordination and stepping characteristics when turning at different speeds. We expected there would be differences in whole-body coordination and stepping characteristics between the sexes with females having less coordination for the whole-body than males during turning.
The data showed that males and females had the same strategy used for turning 180° no matter how fast they turned. In addition, they used step duration and total number of steps to an equal extent regardless of difference in speeds as shown by non-significant differences in the step duration and total step. There were also no significant differences in other variables between the two groups. The only significant differences between the male and female groups were during fast turning for the leading foot onset, and in the slow speed for the step duration. The similarity of turning kinematic characteristics in our population regardless of sex are consistent with a previous study, specifically following the top-down sequence as analysed from segment onset latencies (32). Additionally, the segment onset latencies were similar to those in the younger adult group in the previous study (32). Regarding the significant difference in the leading foot onset between male and female at fast speed, the raw data from the male group also showed a faster speed than the female group. This finding might reflect the response to the visual or auditory stimuli used in this study. The motor cortex and motor planning would control those responses, which are represented by the reaction time. Importantly, based on a previous study, males had faster responses in comparison to females (33). However, it is important to note that generalizations about sex can vary depending on individual circumstances, and not all females or males may fit into these general observations.
When comparing between speeds within each group, the strategy of turning was found to be consistent with a previous study with regard to the top-down sequence and was dependent on the different speeds in both sexes (31). There were, however, significant differences in head, thorax, pelvis, and leading foot onset latencies, peak head on pelvis and step duration with turn speed regardless of sex. These findings indicate that the difference in sex may not influence those variables.
These findings are pertinent to segment onset latency and are consistent with previous studies indicating that different speeds during turning may impact on whole-body coordination and stepping characteristics regardless of any differences in sex (31). However, some characteristics including trailing foot onset latency, step size, and total number of steps may be influenced by sex which was highlighted by significant differences within the males only when comparing different turning speeds, with no such differences seen in the females. With regards to the step size, the result in the male group decreased, while the total step increased during slower turns, a finding consistent with a previous study. In contrast, the step size in the female group did not reduce during slower turns in comparison to the fast turns. In addition, participants within the female group showed a significant difference in peak head yaw velocity, which was not found in the male group. The pairwise comparisons found a significant difference among speeds within the female group between fast and slow speed, and moderate and slow speeds for peak head yaw velocity. The results in the female group are consistent with the previous study which found that peak head yaw velocity reduced during turning in a slow speed (31). This finding is not consistent with the results in the male group because the variability of difference between the speeds did not reach significance.
Thomas et al. (1998) found that familiar biological sex differences such as those in anthropometry, flexibility, or strength could not explain the distinctive movement patterns used by females when compared to their male counterparts. They suggested a potential role for sociocultural constraints on the stereotypical movement patterns of females, whereby forward inclination of the trunk is reduced compared to that of males in tasks that necessitate some bending of the trunk. This suggests a potential role for sociocultural constraints on the stereotypical movement patterns of females (34). Furthermore, it is essential to consider various factors that could contribute to this perception. For instance, females tend to have a lower centre of gravity compared to males due to differences in body composition (35-37). This can affect their balance and stability control. Additionally, hormonal changes during the menstrual cycle can also affect a woman's balance (38, 39). Fluctuations in hormone levels can also lead to changes in joint laxity and muscle coordination, potentially impacting the ability to maintain balance (39).
In addition to whole-body coordination and step characteristics, this study found a non-significant difference in the TUG test in relation to the risk of falls, which did not support our hypotheses. In this current study, there might be some bias due to the relatively narrow age range of the participants. Specifically, the average age for males was 21 years, and for females, it was 22 years. Therefore, the findings may not fully represent the broader population. Previous research suggests that muscle mass and strength tend to decrease between the ages of 30 and 80 (40). Another possible explanation may be that turning movements have most typically been characterized in terms of kinematics, muscle activation (electromyography), joint stiffness, and interjoint coordination in research into the movement process. However, due to the complexity of neuromuscular regulation, sex differences indicated by these measurements might conceivably emerge from peripheral, spinal, or central nervous system levels, as well as motor and/or perceptual domains (41).
The study into differences in sex with regards to turning needs to be expanded beyond biological factors to include environmental and sociocultural factors that influence motor skills. To investigate differences between females and males in healthy young adults, it may also be fruitful to consider participants on an individual basis, taking account of their skills, histories, strength, anatomical differences and cultural attitudes.
The limitation of this study is that we did not control the characteristics of the participants in terms of body weight, height, and body mass index. This might impact on the whole-body coordination and stepping characteristics. In addition, this sample had an average age of 20 years old with a very narrow standard deviation, which may not show the differences in physiology and other factors between males and females which may be seen in older adults.