Reliability of the Modified In-hand Manipulation Test and the Relationship Between In-hand Manipulation and Handwriting

Objectives: This study aimed at analyzing the test-retest and interrater reliabilities of the Test of In-Hand Manipulation-Modified (TIHM-M), as well as the relationship between in-hand manipulation and handwriting. Methods: We administered the TIHM-M twice, two days apart, and the Beknopte Beoordelingsmethode voor Kinder Handschriften (BHK) - Concise Assessment Method for children’s handwriting test once to 105 children (51 boys and 54 girls) aged 6.5 to 9.5 years in regular school. Speed and quality of in-hand manipulation and handwriting were recorded. We performed a Pearson correlation test for the relationship between the speeds and the qualities of the TIHM-M and the BHK. Results: Test-retest of the TIHM-M was excellent for the speed (ICC=0.84; 95% CI:0.73-0.90) and good for the quality (ICC=0.62, 95% CI:0.36-0.78). Interrater reliabilities for both speed (ICC= 0.87; 95% CI:0.78-0.92) and quality (ICC= 0.86, 95% CI:0.60-0.84) were also excellent. We found a significant relationship between the speeds of the TIHM-M and the BHK, but there was no significant relationship between the qualities of handwriting and the TIMH-M. Discussion: The TIMH-M assessed the speed and the quality of in-hand manipulations, and it had good reliability. Nevertheless, the relationship between in-hand manipulation and handwriting needs more investigation to be confirmed.