Tests & Measures: A Resource for Pediatric Physical Therapy Practitioners

Test of Gross Motor Development – 2 (TGMD-2)

I. Descriptive Information

A. Title, Edition, Dates of Publication and Revision

1. Test of Gross Motor Development-2 (TGMD-2)
2. 2^nd edition
3. Published in 2000
4. The TGMD-2 has recently been revised, and the 3^rd edition of this test is expected to be published this year (2015).

B. Author(s)

1. Dale A. Ulrich, PhD

C. Source (publisher or distributor, address)

1. Published and distributed by ProEd, Inc.
2. Address: 8700 Shoal Creek Blvd, Austin, TX, 78757-6897

D. Costs (booklets, forms, kit)

1. The complete kit, including the Examiner’s Manual and 50 Profile/Examiner Record Booklets can be purchased for $126.00 from http://www.proedinc.com/customer/productView.aspx?ID=1776.

E. Purpose

1. The TGMD-2 is the most commonly-used means for assessing the gross motor skills of children in the US between the ages of 3 to 10 or 11 years old. While it was already popular in elementary schools, the CDC recently (2012) made this test a requirement for all 3-5 year olds participating in the National Youth Fitness Survey.
2. Specifically, the test assesses twelve different tasks within two realms of motor development: 1) locomotor (run, gallop, hop, leap, horizontal jump, slide) and 2) object control (striking a stationary ball, stationary dribble, catch, kick, overhand throw, underhand roll) domains.

F. Type of Test (eg, screening, evaluative; interview, observation, checklist or inventory)

1. The TGMD-2 is a norm-referenced discriminative test that requires the observation of 12 different gross motor skills divided into 6 locomotor and 6 object control tasks.
2. The test is ideally administered on an individual basis but may be administered in small group settings.

G. Target Population and Ages

1. 3-10 or 11 years old
2. The CDC recommends this test be administered to all 3-5 year-old children participating in the National Youth Fitness Survey.

H. Time Requirements – Administration and Scoring

1. The test takes between 15 and 20 minutes to complete and score, though this time may vary with the child’s abilities.
2. Scores are recorded simultaneously with task performance and completion.
3. Scores can either be “0” (failed attempt) or “1” (successful completion) for each performance criterion within each motor skill.

 II. Test Administration

A. Administration

1. Prior to administering the test, the examiner must ensure the participant is appropriately clothed (rubber-soled sneakers are tied, no baggy clothes).
2. Hand and foot dominance must be determined prior to testing. This can be achieved by giving the participant a high five and asking him or her to kick a ball, respectively.
3. The following administration protocol has been established to ensure accuracy in data collection and reporting:
   1. Examiner accurately demonstrates and verbally explains the desired task to the participant prior to asking the participant to perform the task.
   2. The child gets one practice trial to ensure understanding of the expected task.
   3. If the child demonstrates a lack of understanding of the requested task, the examiner must offer a second demonstration.
   4. Assess two test trials, recording the appropriate performance criterion score for each trial.

B. Scoring (see attached file for scoring charts: TGMD-2 Scores Conversion Tables)

1. Each task has a specific set of behavioral components comprising the performance criteria for each skill. Each criterion within each gross motor skill receives a score of either “1” for successful completion or “0” for a failed attempt.  Should a child refuse to participate in a task, the examiner would mark the “did not participate” box on the software program.
2. The scores of “0” or “1” are applied for each performance criterion for both trials performed for each skill. These scores are then summed to generate a raw skill score based on each component of each motor skill.
3. Adding the skill scores of the six specific movement tasks under each domain yields a raw subtest score for the locomotor and object control categories.
4. The raw subtest score is converted to a standard score, percentile, and age equivalent based on algorithms outlined in the appendices of the Examiner’s Manual and included in the attached file.
5. Standard scores for both subtests are added and converted to an overall Gross Motor Quotient.

C. Type of information, resulting from testing (e.g. standard scores, percentile ranks)

1. The TGMD-2 yields standard, numeric scores.
2. For greater clinical value, these scores may be converted to percentiles, age equivalents, or a Gross Motor Quotient (sum of locomotor and object control subtest scores).

D. Environment for Testing

1. The 2^nd edition of the TGMD has been modified to allow its administration in confined spaces, such as mobile classrooms. A hallway or open space with a straight path of at least 28’ and a square area of at least 15 square feet is required to complete all components of the test.
2. A space measuring 60’ x 30’ is recommended for ease of test administration.
3. A wall at which a ball may be kicked and thrown should also be present in the space to reduce time spent fetching balls after each test.

E. Equipment and Materials Needed

1. The TGMD-2 requires a variety of equipment that is readily available in clinical or physical education settings including: cones, masking tape, 4-5″ beanbags, plastic bat, Nerf ball, batting tee, 8-10″ plastic playground ball or soccer ball, 4″ plastic ball, and a tennis ball.

F. Examiner Qualifications

1. It is recommended that the TGMD-2 be administered by kinesiologists, general and special physical educators, psychologists, occupational therapists, or physical therapists, as these professionals have experience in observing movement skills and identifying impairments.
2. All administrators must possess and be familiar with the instructions outlined in the Examiner’s Manual. This manual will also serve as the script used during test administration to ensure consistent and accurate directions are provided to all participants.  All data is input into a computerized Integrated Survey Information System (ISIS).
3. It is recommended that all examiners receive supervised practice in administering and interpreting the test to ensure accuracy of data collection.

G. Psychometric Characteristics

1. Evidence of Reliability
   1. Overall, the TGMD-2 is reported to be a test that yields results in which examiners can be confident due to the low level of test error it possesses. The reliability of the TGMD-2 has been reported based on three different sources of error variance:
      1. Content Sampling (internal consistency): reflects the degree of similarity among the skills tested; reliability coefficients > 0.8 and low standard error measures suggest the TGMD-2 is a reliable test; studies of various population subgroups (i.e. different genders, races, and ethnicities) yield similar findings suggesting the TGMD-2 is a reliable test.
      2. Time Sampling: a test-retest method conducted on 75 subjects indicated a high magnitude of correlation (≥ 0.88) between the two trials, suggesting the TGMD-2 is a reliable test in terms of its stability over time.
      3. Interscorer/Intrascorer Differences: Strong intertester reliability (0.98) was supported through a study comparing the scores assigned by two independent examiners.  Further studies on a larger sample size of examiners may be useful in assuring consistency in scoring among administrators.  Similarly, strong intratester reliability has been demonstrated via consistency of scorers in assigning appropriate and comparable scores when similar performances are demonstrated by different subjects.

2. Evidence of Validity
   1. The validity of the TGMD-2 has been reported through the following three components. While different studies focusing on various populations have yielded slight differences in validity measures, all studies consistently support that the test yields strong validity and is deemed a valid instrument for assessing gross motor skill development in children.
      1. Content-Description: Three independent content experts independently and unanimously determined that the 12 motor skills assessed via the TGMD-2 accurately and appropriately represent the fundamental gross motor skills expected of the target age group. Furthermore, an item analysis suggested the included tasks satisfy item discrimination and difficulty criteria.
      2. Criterion-Prediction: To determine criterion-prediction validity, a test is compared to another, well-respected test intended to measure the same outcomes.  The TGMD-2 was compared to the Basic Motor Generalizations subtest of the Comprehensive Scales of Student Abilities.  Because of the moderate to strong correlation between these measures, the TGMD-2 has been deemed to be efficacious in predicting a child’s performance in specific movement tasks.
      3. Construct-Identification: Studies support the validity of the TGMD-2 in 5 different constructs: 1) differentiation between ages based on performance, 2) differentiation between groups based on performance (i.e. a group of subjects with developmental disabilities would be expected to score lower than typically-developing peers), 3) correlation between individual task performance scores and the overall score, 4) correlations between subtests, and 5) appropriateness of selected skills within each domain of motor development and skill performance.

3. Level of Measurement
   1. The TGMD-2 yields interval level data, as a score of zero for a performance criterion does not always represent a complete inability to carry out a task as partial completion is still characterized as a failed attempt.
4. Responsiveness
   1. There is no published statistical data reporting internal and external responsiveness of the TGMD-2 at this time.

H. Standardization/normative data

1. Normative data has been comprised based on a sample of 1208 children from 10 states.
2. Norms are included in the Examiner’s Manual that testers receive when the kit is purchased.

 III. Summary Comments

A. Strengths

1. Tests a variety of skills within two different performance domains of gross motor development.
2. Detailed guide outlines very specific instructions for test administration to ensure repeatability of tests.
3. Each motor skill is broken down into various performance criteria which aids in identifying the specific movement component(s) that may be lacking in a child.
4. Requires easy-to-obtain equipment, most of which would already be available in school/clinic settings.
5. May be administered in a relatively short amount of time.
6. Includes norm-referenced values.
7. Ease of administration due to familiarity of tasks.
8. Offers multiple means to present the scores.
9. Norms are based on a large sample size (n = 1208) deemed representative of the entire US school-aged population.

B. Weaknesses

1. Somewhat extensive set-up to ensure all the materials are organized, space is appropriately cleared, etc.
2. Performance criterion scores are either “0” or “1”, meaning there is no room to account for partial completion of a task or inconsistency of performance across trials.
3. Scores do not identify the underlying cause explaining why a child may be performing at a lower level than would be predicted for his or her age.
4. Numerous confounding variables cannot be accounted for, including such factors as the participant’s motivation, emotional state, and levels of prior exposure to and practice of the gross motor skills.
5. Affords no special accommodations for non-ambulatory children.
6. Assigning the scores of “0” or “1” to the performance criteria requires a certain degree of subjective interpretation of performance.

C. Clinical Applications

The results of the TGMD-2 have vast clinical applications, including the following:

1. Identification of children who may be behind their peers in gross motor skill development, thus suggesting a need for adaptive or special services in physical education in an effort to remediate the limitations and prevent lifelong involvement;
2. Serving as a guideline in designing motor development programs and IEPs to specifically address the skills in which a patient’s performance may be lacking;
3. A means for tracking the child’s improvements over the course of a motor development program or IEP;
4. A foundation for understanding the extent of a child’s ability to perform fundamental motor skills that will serve as building blocks in the later development of sport-specific movement abilities;
5. Early intervention to address movement limitations that could contribute to social alienation later in life;
6. Serving as a guideline for goal setting.

References:

I was fortunate to be able to gather most of this information via access to a PDF of the examiner’s manual found at the following link: http://33202576.weebly.com/uploads/1/4/6/8/14680198/tgmd-2-2.pdf

The CDC has also published a reference to this test in conjunction with its National Health and Nutrition Examination Survey.  It may be found at the following link: http://www.cdc.gov/nchs/data/nnyfs/TGMD.pdf

Article Summary:

Cohen K, Morgan PJ, Plotnikoff RC, Callister R, & Lubans DR.  Fundamental movement skills and physical activity among children living in low-income communities: a cross-sectional study.  Int J Behav Nutr Phys Act 2014; 11(1): 49-57.

The purpose of this study was to assess the correlations between fundamental movement skill competency and duration of moderate-to-vigorous physical activity (MVPA) observed in low-income, primary school children in Australia.  Four hundred and sixty students were enrolled in the study and wore accelerometers for 7 consecutive days to track daily physical activity.  During school days, researchers specifically keyed in on MVPA levels during lunchtime, recess, and a 3-hour window after school, as these critical periods have previously been shown to be able to contribute to upwards of 65% of a child’s recommended daily physical activity.  Motor skill competency was tested on one occasion using the Test of Gross Motor Development-2 (TGMD-2), which assesses twelve different locomotor and object-control skills.  Secondary outcome measures recorded included participant height, weight, and demographics to ensure differences could not be attributed to confounding factors related to these variables.  Results of the study found that children accumulate roughly 50% of their daily MVPA during the critical periods defined.  Additionally, competency in locomotor skills was positively correlated with total daily and after-school MVPA, whereas object-control skill competency was positively related to total, lunchtime, recess, and after-school MVPA.  In general, children with higher competency scores within both realms of the TGMD-2 participate in longer periods of MVPA after school, a finding the authors attribute to a greater tendency to be active due to confidence generated from demonstrated abilities that allows more inclusive participation in sports-specific activities.  Similarly, more competent children engage in roughly 5% more MVPA during physical education classes compared to less competent peers due to the fact that higher skill competency allows the children to achieve a higher level of activity.  At this time, the precise relationship between motor skill competency and physical activity is unclear.  In particular, researchers are uncertain if higher competency yields greater levels of participation or if greater participation contributes to improved competency.  Either way though, researchers cite the findings of this study as valid evidence supporting the need for schools to ensure the availability of facilities and equipment throughout the school day so children may engage in activity while simultaneously having means to improve skill competencies.

This study has several strengths including: 1) the use of a comprehensive tool such as TGMD-2 to assess movement competency, 2) objectively tracking physical activity levels, 3) employing a large sample size, and 4) adjusting all results to eliminate a potential confounding influence from factors like patient height, weight, and demographics.  Despite these strengths, there are several limitations as well including: 1) underestimation of accelerometer data with certain types of activity, like swimming and non-ambulatory activity and 2) an inability to ascertain whether there is a causal relationship between skill competency and physical activity levels.  However, the results do resoundingly suggest that physical activity levels are increased when children demonstrate higher levels of movement competency.  With such knowledge, schools should emphasize making physical activity possible during breaks during the day, in an effort to promote adequate skill development that may contribute to higher levels of lifelong physical activity participation.

 

 

 

 

One response to “Test of Gross Motor Development – 2 (TGMD-2)”

1. achristian5 says:

   March 15, 2015 at 8:10 pm

   Validity and reliability are so important and having the looked at in great detail really helps the administrator place value on the test.

   Log in to Reply