The Peabody Developmental Motor Scales–Third Edition (PDMS-3) is an early childhood motor development program that provides both in-depth assessment and training or remediation of gross and fine motor skills. The assessment measures interrelated motor abilities that develop early in life. The PDMS-3 can be used by occupational therapists, physical therapists, diagnosticians, early intervention specialists, adapted physical education teachers, psychologists, and others who are interested in examining the motor abilities of young children. 

Features 

• The subtests of the PDMS–3 were renamed to reflect a better understanding of the skills required by the items. The three gross motor subtests are now titled Body Control, Body Transport, and Object Control. The two fine motor subtests are now Hand Manipulation and Eye-Hand Coordination. 
  • Body Control: This subtest measures the ability to move the limbs and trunk, postural reactions, standing, bending, extending, stooping, balancing, jumping upward. It is an estimate of the child's ability to sustain control of his or her body within its center of gravity and retain equilibrium. 
  • Body Transport: This subtest measures the ability to make movements that propel the child from one location to another, such as rolling, crawling, creeping, walking, running, jumping forward and sideward, sliding, hopping, and skipping.  
  • Object Control: This subtest measures the ability to coordinate motor movements that require the incorporation of perception and movement, such as throwing, catching, bouncing, and kicking a ball.  
  • Hand Manipulation: This subtest measures the ability to move the hands and fingers (and arms as appropriate) to complete tasks and measure dexterity. This includes manipulation of objects such as blocks, cups, and drawing instruments. 
  • Eye-Hand Coordination: This subtest measures the ability to interpret visual stimuli in coordination with hand-finger movements. It is an estimate of the child's ability to integrate and use his or her visual perceptual skills to perform complex eye-hand coordination tasks. 
• The Examiner Record Booklets now contain complete administration and scoring instructions, allowing administration of the test without using the Examiner’s Manual. 
• The PDMS-3 norms are based on an all-new sample of 1,452 children who were tested from Spring of 2016 through Spring of 2021. 
• The demographic characteristics of the sample were stratified by age to conform to those of the projected U.S. under 5 years of age population for the year 2021 as reported in the ProQuest Statistical Abstract of the United States 2021 (ProQuest, 2021) and are thereby representative of the U.S. population. The demographic characteristics of the sample were also stratified by age for geographic region, race, ethnicity, gender, parent education, and household income. 
• New and extensive studies of test bias (both differential item functioning and subgroup comparison studies) were conducted, indicating the PDMS-3 possesses little or no bias regarding gender, race, or ethnicity. 
• New and extensive criterion-prediction validity studies were conducted to demonstrate the validity of the PDMS-3’s subtests and composites, including diagnostic accuracy and receiver operating characteristic/area under the curve (ROC/AUC) analyses. Diagnostic accuracy analyses are particularly rigorous techniques for establishing validity involving the computation of a test's sensitivity index, specificity index, and ROC/AUC. These studies indicate that the PDMS-3 is a highly valid measure of motor skills. 
• New studies of construct-identification validity, including studies of age differences, subgroup performance, relationship to language, relationship to social-emotional development, and relationship to adaptive behavior were conducted. Factor analyses of the test’s structure by age were also performed. These studies indicated that the PDMS-3’s internal structure is sound, and its results are valid for a wide variety of subgroups, as well as for a general population. 

Composites 

The PDMS-3 has three composites. These composites are derived from combining the results of the subtests to achieve stronger and better indices of performance. The scores of these composites are more reliable and valid than the subtests. 

• Gross Motor Index: This composite is a combination of the results of the Body Control, Body Transport, and Object Control (children 16 months and older) subtests, which measure the use of the large muscle systems. This index score represents the child's ability to use the large muscle systems to react to environmental changes, assume a stable posture when not moving, move from place to place, and catch, throw, and kick balls. 
• Fine Motor Index: This composite is a combination of the results of the Hand Manipulation and Eye-Hand Coordination subtests, which measure the use of the small muscle systems. This index score represents the child's ability to use his or her fingers, hands, and to some extent arms to grasp objects, stack blocks, draw figures, and manipulate objects. 
• Total Motor Index: This composite is formed by a combination of the results of the gross and fine motor core subtests. Because of this, it is the best estimate of overall motor abilities. 
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