All information from the previous posts are current regarding the TGMD-2 and the development of the TGMD-3.  The TGMD-2 has been revised and is currently finalizing the normative data. Publication of the TGMD-3 is expected to occur soon.

One study assessing the reliability and validity of the TGMD-3 was located and is summarized below.

Article Summary

Allen, K. A., Bredero, B., Van Damme, T., Ulrich, D. A., & Simons, J. (2017). Test of Gross Motor Development-3 (TGMD-3) with the Use of Visual Supports for Children with Autism Spectrum Disorder: Validity and Reliability. Journal of Autism and Developmental Disorders. https://doi.org/10.1007/s10803-016-3005-0

The purpose of the article was to test the validity and reliability of screening children with autism spectrum disorder (ASD) using the Test of Gross Motor Development-3 (TGMD-3) with visual aides.  The study aimed to test the ability of the TGMD-3 to assess motor skills in children age 3-10 and to test the inclusion of visual aides to a gross motor skills assessment in children with ASD.  The study was conducted in Australia and used a convenience sampling of 14 children with ASD and a snowball sampling of 21 typically developing children between the ages of 4 and 10. The authors administered the TGMD-3 on the study population of children with ASD using only verbal and physical cues and a second TGMD-3 assessment with visual cue cards for task instruction. The tests were performed on consecutive days, the sequence of tasks was randomized and half the study population started with the TGMD-3 with visual cues and the other half started with the TGMD-3 with only verbal and physical cuing. The typically developing children group only received the TGMD-3 assessment with verbal and physical cuing.  The testing protocol included consistent room setup, color coordinated task stations, and a familiarity period for ASD participants to be introduced to the testing environment and staff. Children with ASD were allocated 45 minutes to complete testing while children in the typically developing group were allocated 30 minutes to complete the motor skills assessment. All TGMD-3 trials included in the study were videotaped and a video analysis software (Dartfish Version 7.0) was used to produce raw scores for TGMD-3.

Statistical analysis of the results was performed to test the reliability and validity of the TGMD-3. Internal consistency at acceptable levels was reported with all groups and subsets of the TGMD-3 except the ball skills subtest in the typically developing children group. Excellent levels of agreement for the test-retest, interrater and intrarater reliability were also reported in the both the typically developing children group and the children with ASD group using both the traditional protocol and the visual aides protocol.

The authors note large standard error measurements in the study and state that it can be expected in this study population, but limits the results’ generalizability. The authors also note limitation of some continued confusion with visual aides within the ASD group. They suggest that less confusing instruction illustrations with the least amount of verbiage is ideal. Some of this confusion was also attributed to developmental differences within the study age range of 4-10; however, it may be possible to improve upon the picture cards used in this study. It is noted that normative data for the TGMD-3 for the general population are still being collected and are not available. The small sample size also limits the generalizability of the findings, but was realistic for such a randomized controlled trial.

The TGMD-3 locomotor subset, ball skills subset, and overall scores of the traditionally developing children were significantly higher than children with ASD with using the TGMD-3 traditional protocol and matched for chronological age and sex. This supports the use of the TGMD-3 to identify children with motor skills deficits. Additionally, a statistically significant difference was shown in the children with ASD group between the scores using the TGMD-3 traditional protocol and the TGMD-3 visual aide protocol.  This supports the inclusion of visual aide methods for task instruction in order to understand and assess true gross motor performance in children with ASD. The results of this study support the use of TGMD-3 visual aide protocol as a valid and reliable gross motor skills assessment for children with ASD and support the inclusion of visual instruction to enhance task understanding in this population.