Rhythmic ability decline in aging individuals: The role of movement task complexity

Study aim: To investigate age-related changes in rhythmic reproduction ability in relation to the complexity of the adopted movement task. Material and methods: A Stereophotogrammetric system was used to quantify individual rhythmic performances through motion analysis. Seventeen younger adult (age: 34.8 ± 4.2 yrs) and sixteen older adult (age: 69.9 ± 3.8 yrs) sedentary individuals volunteered for this study. Participants were administered a rhythmic test, which included three different rhythmic patterns to be reproduced by means of finger-tapping, foot-tapping and walking. Number of correct reproductions, time delays and rhythmic ratios were assessed and submitted to analysis of variance. Results: For all rhythmic parameters, age-related differences emerged about rhythmic patterns and motor tasks. Older adults showed reduced accuracy as compared to their younger counterparts with a marked tendency to speed up beats reproduction (p < 0.05). Increased movement complexity negatively influenced rhythmic ability, with worst performances in the walking task (p < 0.05). Conclusions: Complexity of the motor reproduction worsen rhythmic ability. Future research should focus on how specific rhythmic training with progressive movement task complexity could contrast this age-related decline.

Exploring The Power Clean

The power clean and its variations are prescribed by strength and conditioning coaches as part of the ‘big three’ to develop “total body strength”. This article explores the application of the power clean and its variations to athletic performance and introduces strength and conditioning coaches to teaching progressions, with specific emphasis on developing the correct body positioning required for the power clean. Teaching components are addressed with special reference to taller athletes. It is recommended that strength and conditioning coaches teach the hang clean follow a progression model to decrease movement complexity when advancing athletes to the power clean.

Complexity of Body Movements during Sleep in Children with Autism Spectrum Disorder

Recently, measuring the complexity of body movements during sleep has been proven as an objective biomarker of various psychiatric disorders. Although sleep problems are common in children with autism spectrum disorder (ASD) and might exacerbate ASD symptoms, their objectivity as a biomarker remains to be established. Therefore, details of body movement complexity during sleep as estimated by actigraphy were investigated in typically developing (TD) children and in children with ASD. Several complexity analyses were applied to raw and thresholded data of actigraphy from 17 TD children and 17 children with ASD. Determinism, irregularity and unpredictability, and long-range temporal correlation were examined respectively using the false nearest neighbor (FNN) algorithm, information-theoretic analyses, and detrended fluctuation analysis (DFA). Although the FNN algorithm did not reveal determinism in body movements, surrogate analyses identified the influence of nonlinear processes on the irregularity and long-range temporal correlation of body movements. Additionally, the irregularity and unpredictability of body movements measured by expanded sample entropy were significantly lower in ASD than in TD children up to two hours after sleep onset and at approximately six hours after sleep onset. This difference was found especially for the high-irregularity period. Through this study, we characterized details of the complexity of body movements during sleep and demonstrated the group difference of body movement complexity across TD children and children with ASD. Complexity analyses of body movements during sleep have provided valuable insights into sleep profiles. Body movement complexity might be useful as a biomarker for ASD.

Impact of Distracting Emotional Stimuli on the Characteristics of Movement Performance: A Kinematic Study

It is well-documented that emotional stimuli impact both the cognitive and motor aspects of “goal-directed” behavior. However, how emotional distractors impact motor performance remains unclear. This study aimed to characterize how movement quality was impacted during emotional distractors. We used a modified oddball paradigm and documented the performance of pure movement. Participants were designated to draw a triangle or a polygon, while an emotional stimulus was presented. Speed was assessed using reaction time and movement time. The quality and precision of movement were assessed by calculating the accuracy and root-mean-square error (RMSE). Compared to drawings of triangles, polygons had higher accuracy under negative stimuli, but lower RMSE under positive stimuli. The results indicate that distracting emotional stimuli impact different aspects of movement quality, with movement complexity influencing accuracy under negative distractors and precision under positive distractors. This study provides further evidence that movement precision is an important feature of emotional embodiment that should be incorporated in future studies.

Longitudinal assessment of U-shaped and inverted U-shaped developmental changes in the spontaneous movements of infants via markerless video analysis

Various attempts have been made to elucidate the development patterns in the spontaneous movements of infants through longitudinal evaluations. Movement complexity has been found to demonstrate u-shaped changes in the measurements focusing on limb movements. However, researchers have not yet clarified how other characteristics, besides movement complexity, change over time. This paper presents a longitudinal evaluation of spontaneous movements in infants using evaluation indices calculated through markerless video analysis. Nine infants with corrected ages from $$-1$$ - 1 to 15 weeks participated in the experiments. We confirmed the change in indices over time using statistical methods. Index changes can be classified as positively correlated, u-shaped, inverted u-shaped, and uncorrelated. We also confirmed that the u-shaped and inverted u-shaped indices are negatively correlated. Furthermore, the principal component analysis revealed that the first principal component had the inverted u-shaped changes with the corrected age. These results suggest that it is important to synchronize the inverted u-shaped variations in the movement and velocity with the u-shaped changes in the movement complexity for infant development.