Does data distribution change as a function of motor skill practice?
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Adolescent↗
Biomedical subjects
Jin H Yan
Publications and source records attributed to Jin H Yan.
Young girls' developmental skills in underarm throwing.
This paper concerns underarm throwing by girls 7 to 12 years of age. Each movement component by trained and untrained girls in underarm throwing or windmill softball pitching was examined. Movement characteristics of ball release, arm motion, trunk activity, and stepping were analyzed to capture experience- and age-related differences in underarm throwing. A total of 48 young girls participated: 25 untrained (age 9.7 yr.), 14 trained/league (age 10.9 yr.), and 9 trained/formal (10.4 yr.). Performance was videotaped individually and evaluated by three observers. Analyses suggest that, while age did not affect performance, the type of training experience influenced the girls' performance on each of the four movement components. The wrist and trunk were identified as showing the most significant progression with experience. The findings have important implications about changes during acquisition of underarm throwing skills.
Axilla↗
Physical activity, physiological, and psychomotor performance: a study of variously active older adult men.
This research examined varying levels of physical activity and psychomotor and physiological function in variously active older men. Very active moderately active, and low active participants were tested on simple (SRT) and choice reaction time (CRT), coincidence-anticipation timing (CAT), and VO2max. No significant differences for age or height were found, although percentage of fat, and weight were statistically different. Active groups were leaner and lighter. VO2max was significantly different between groups, as physically active groups yielded geater values. SRT and CAT also yielded significantly different results with more active participants showing better performance. No between-groups significant differences resulted for CRT. Generally, increased levels of physical activity were related to superior physiological outcomes and improved psychomotor peformance.
Aged↗
Developmental differences in children's ballistic aiming movements of the arm.
An experiment was conducted to examine the change in the relation between programming and "on-line" correction as a developmental explanation of children's arm movement performance. Each of 54 children in three age groups (5, 8, and 10 yr.) completed two types of rapid aiming arm movements in the longitudinal plane on the surface of a digitizer. Percent primary submovements and timing variability were dependent variables. Analysis suggested that the 5-yr.-olds used "on-line" monitoring during the arm movement and did not perform the movement sequence as a functional unit. Compared with 8- and 10-yr.-olds, the 5-yr.-olds planned a smaller portion of movements, executed the arm movements with more variability in time to peak velocity. The 8- and 10-yr.-olds appeared to plan their movements and execute the sequence as a unit. The developmental implications were discussed.
Age Factors↗
Arm movement control: differences between children with and without attention deficit hyperactivity disorder.
The purpose of this study was to examine performance differences in arm movement control (programmingvs. "on-line" control) between children with and without attention deficit hyperactivity disorder (ADHD). Twenty children (10 with ADHD and 10 without ADHD) from the ages of 8 to 13 years participated in the study. On the surface of a digitizer, each participant completed three types of aiming arm movements (10 trials for each) and 10 baseline trials (without accuracy requirement). Multivariate analyses of variance with repeated measures were used to analyze the variables of reaction time, movement time, normalized jerk, intersegment-interval (ISI), and movement timing. Children with ADHD appeared to use "on-line " monitoring during the arm movement and did not perform the entire movement sequence as afunctional unit. They executed the arm movements more slowly, had greater variability in movement timing, and demonstrated longer ISIs than their counterparts. Children with ADHD had multiple peaks in the velocity profiles. Children withoutADHD, however, appeared to program their entire arm movements and execute the sequence as a unit. Their velocity profiles were symmetrical with a single peak, and the movement segments were temporally coordinated. Thesefindings suggested that cognitive functions are important resources for controlling rapid aiming arm movements. Children with ADHD might rely more on visual feedback during the movements, which resulted in slower and more variant movement outcomes than children who did not have ADHD.
Adult↗
Practice effects on motor control in healthy seniors and patients with mild cognitive impairment and Alzheimer's disease.
This research was designed to test the hypothesis that motor practice can enhance the capabilities of motor control in healthy controls (NC) and patients with a diagnosis of probable Alzheimer's disease (AD) and mild cognitive impairment (MCI), and consequently results in better motor performance. Approximately half of the subjects in the NC (n = 31), AD (n = 28), and MCI (n = 29) either received or did not receive practice on a task of fast and accurate arm movement with a digitizer. Changes in movement time (MT), movement smoothness (jerk), and percentage of primary submovement (PPS) were recorded and compared among the three groups across six blocks of trials (baseline and five training sessions). For all subjects, practice improved motor functions as reflected by faster and smoother motor execution, as well as a greater proportion of programming control. Compared to unaffected matched controls, AD and MCI subjects exhibited a greater reduction in movement jerk due to practice. Movement time and PPS data revealed that motor practice appeared to reduce the use of "on-line" correction adopted by the AD or MCI patients while performing the aiming movements. Evidently, their arm movements were quicker, smoother, and temporally more consistent than their untrained peers. The findings of this study shed light on how MCI and AD may affect motor control mechanisms, and suggest possible therapeutic interventions aimed at improving motor functioning in these impaired individuals.
Aged↗