CHAPTER 42: BOX AND BLOCK TEST (BBT)

Description

The Box and Block Test (BBT) is a standardized measure of unilateral gross manual dexterity as well as various hand/finger grip functions such as the pincer grasp, three jaw chuck, pad to pad, and lateral prehension. The BBT is appropriate for a number of developmental and other conditions, such as stroke, where a person’s grasp or his or her ability crossing the midline may be of concern. During assessment, the subject is asked to pick up as many small, square, 2.5-cm blocks as possible from one compartment of a box and place them into another compartment in a 60 second time frame. The box, explained in detail by Mathiowetz, Volland, Kashman, and Weber (1985), when open forms two compartments with a partition in the middle that is high such that the subject must reach over the partition to place the blocks into the other side. The unit is typically constructed of plywood (1 cm) that in its open state is roughly 53 × 53 cm with 8.5-cm sides. In the middle of the open box is a 15-cm high partition. The box is designed to fold into an easy-to-use carrying case. The assessment comes with 150 cubes that are 2.5-cm squares, made of wood and colored blue, green, red, and yellow. Scoring involves the number of cubes moved from one compartment to the other in 60 seconds. The BBT can be completed and scored in less than 5 minutes.

Psychometrics

A study of test-retest reliabilities of 35 able-bodied subjects ranged from r = 0.90 right hand and 0.89 left; whereas reliabilities of 34 impaired subjects were r = 0.97 right and 0.96 left (Desrosiers, Bravo, Hébert, Dutil, & Mercier, 1994). A study of 27 occupational therapy student subjects found inter-rater reliability, using 2 raters, to be nearly identical for the right hand at 1.0 and for left hand 0.99 (Mathiowetz et al., 1985). Another inter-rater and intrarater reliability study of subjects with rheumatoid arthritis (RA; n = 60), using 2 raters, ranged from r = 0.92 to 0.97 and r = 0.91 to 0.95, respectively. The same study found dexterity scores of those with RA were lower when compared to controls for the dominant hand (54.87 vs 68.18), contralateral hand (52.65 vs 65.6), as well as with population-based normative scores; dominant hand (54.87 vs 80.02) contralateral hand (52.65 vs 77.23) (Ranjan, Raj, Kumar, Sandhya, & Danda, 2015). A study of 104 subjects aged 60 to 94 years found that correlations between the BBT and the Action Research Arm Test were significant (0.80; right hand and 0.82; left); whereas correlations between the BBT and the Functional Autonomy Measurement System—activities of daily living subsection and total score were moderate at 0.42 right and 0.54 left and 0.47 right and 0.51 left (Desrosiers et al., 1994). Standardized norms have been established for the BBT using a sample of 628 20- to 94-year-old subjects, which noted that test scores typically decrease with age evidenced by scores of the 20- to 24-year-old age group were 88.0 right and 83.4 left compared to the 70- to 74-years-old age group (68.6 right and 68.3 left) (Mathiowetz et al., 1985). A similar study of 360 subjects aged 60 years or older, also to establish standardized norms, obtained a mean score of 66.9 for the right hand and a mean of 66.3 for the left (Desrosiers et al., 1994).

Advantages

There is a significant amount of literature in support of its use in clinical practice and no special training or certifications are required to administer the BBT. There are also well-established norms available for the assessment across the lifespan in a number of studies. The assessment has remained relatively unchanged from its original description in 1957 and administration time is less than 5 minutes.

Disadvantages

The box when closed may be considered by some to be awkward. The BBT is also more expensive than some of the pegboard assessments described later in this section and its availability may be limited to only a few therapy outlets. The inherent reward from moving blocks from one place to another may be limited as well, and because the test requires rapid movements, may add a stress component not found in more routine tasks (Canny, Thompson, & Wheeler, 2009).

Administration

During assessment the subject is asked to pick and place as many blocks as possible from one box compartment into another over a small partition in 60 seconds. The individual is scored on how many blocks can be placed in the allotted time. The examiner’s manual has detailed instructions as well as standardized norms. Alternative scoring norms are available elsewhere.

Stay updated, free articles. Join our Telegram channel

Join