CHAPTER 45: MINNESOTA MANUAL DEXTERITY TEST (MMDT) AND MINNESOTA RATE OF MANIPULATION TEST (MRMT)

Description

The Minnesota Manual Dexterity Test (MMDT) and the Minnesota Rate of Manipulation Test (MRMT) are considered large board assessments typically used to measure eye-hand coordination as well as gross motor arm quality and hand dexterity opposed to the fine motor quality of some of the pegboard assessments discussed prior. Both are relatively quick outcome measures that utilize similar hardware (i.e., a long board with holes in which blocks must be placed or displaced from the holes using various techniques). In particular, the original version MRMT consists of 2 wooden boards, 81.2-cm long, 22.9-cm wide, and 2.7-cm thick that rest on top of each other (Surrey et al., 2003). Each board has 60 holes, 3.8 cm in diameter and 1.3 cm deep and designed to fit inside the holes are 60 cylindrical blocks, 3.5 cm in diameter and 2.2 cm high (Surrey et al., 2003). The cylindrical blocks are yellow on one side and orange on the other side. The newer MMDT dimensions consist of one plastic accordion-style collapsible board that is 85.4-cm long, 22.8-cm wide only 0.5-cm thick (Surrey et al., 2003). The collapsible board also has 60 holes, 3.9 cm in diameter and 0.5-cm deep. The same number of cylindrical blocks (60) fit into the holes and measure 3.7 cm in diameter and 1.9-cm high (Surrey et al., 2003). The cylindrical blocks are red on one side and black on the other side. During assessment of both boards the person’s abilities are scored relative to speed and correctness in completing a combination of 3 basic tasks: (1 to 2) placing or displacing the discs and (3) variations of turning the discs, such as, how quickly a subject can pick up each disc with one hand, turn them over into the other hand and replace them back into the hole on the board (Tajmir & Carnahan, 2013). The older MRMT has 5 distinct subtests with well-established referenced norms for placing, turning, displacing, one-hand turning and placing, and two-hand turning and placing. The newer MMDT manual only formally has directions for the placing and turning tests; however, the manual makes numerous references to the original MRMT and its norms, thus it is assumed that the 5 tests can be completed with the newer MMDT board as well. Time to complete all of the subtests is less than 15 minutes

Psychometrics

An MRMT study of 118 subjects treated surgically by a hand surgeon found that inter-rater reliability using 2 independent raters was moderate at r = 0.75 (Gloss & Wardle, 1982). Whereas a study by Jurgensen, (1943) showed that a 2 trial test-retest reliability for placing was r = 0.87, turning 0.91, 1-hand turning and placing 0.95, and 2-hand turning and placing 0.94; while a 4 trial reliability for placing was r = 0.93, turning 0.95, 1-hand turning and placing 0.98, and 2-hand turning and placing 0.97 representing highly significant consistencies. Desrosiers, Hébert, and Bravo (1997) found that test-retest reliability of the MMDT subtests ranged from r = 0.79 to 0.88 and correlation coefficients with the Box and Block Test and the Purdue Pegboard Test were moderate at –0.63 and –0.67, respectively. The same study, using only the common placing and turning test when comparing the MMDT with MRMT, found that the 2 were highly correlated at 0.85, 0.95, and 0.95 for right hand, left hand, and turning tests; however, it was also determined that the time required to complete MMDT tasks were longer than that of the MRMT. A study by Surrey et al. (2003) generally concurred with those results of 233 subjects aged 18 to 70 years that yielded statistically significant longer performance times for the MMDT (i.e., placing: MMDT 49.96 seconds vs. MRMT 45.58 seconds and turning subtests: MMDT 62.58 seconds and MRMT 61.23 seconds).

Advantages

There is a large amount of research pertaining to the subtests of both the MRMT and MMDT assessments and available normative data has been derived from large cohorts of people across the lifespan. Testing procedures and scoring have remained stable and relatively unchanged since the 1940s for the MRMT subtests which are often used in the newer MMDT as well. Alas, the MMDT may be considered more refined because it is made of plastic, is sleeker, and is able fold like an accordion into a briefcase. Neither test requires any special training.

Disadvantages

The original MMRT, constructed of wood, can be large and awkward and both tests require a lot of space due to the size of the boards when opened, 81 cm by 22 cm (31 inches x 9 inches) or greater, and since the test is completed in the standing position taller/shorter people may have difficulty with the recommended table height of 28 to 32 inches found in both assessments. Finally, there is less direct research pertaining to the newer MMDT.

Stay updated, free articles. Join our Telegram channel

Join