Table 1.

Summary of studies that have developed instrumented toys to quantitatively assess movement in young children.

Study	Design	Age group	Measures	Findings
Campolo et al. 2008 (28)	Instrumented ball toy sensorized with inertial units (accelerometer, magnetometer, and gyroscope) and custom-made force sensors (0–20 N)	6 months and above, intended for children suffering from autistic spectrum disorders	Applied force Spatial orientation and acceleration of object movement	Not formally tested with infant subjects
Cecchi et al. 2008 (29)	Instrumented rattle, sensorized with inertial units (accelerometer, magnetometer, and gyroscope) and binary contact sensors	9 months and above	Grip shape Spatial orientation and acceleration of movements	Preliminary test with three infants (24 months old) showed typical 3–4 finger grasp patterns
Cecchi et al. 2010 (34) Cecchi et al. 2010 (35) Serio et al. 2011 (32) Sgandurra et al. 2012 (36)	“Biomechatronic gym” (instrumented baby play gym) consisting of three toys (cow-toy, flower-toy, and ring-toy) integrated with visual and auditory stimuli. Toys contain piezo-resistive pressure sensors (0–5 psi) and force sensing resistors (0–20 N)	4–9 months old	Palmar (power) and precision grasp: applied pressure and force range Distinction between lateralized or centralized activity defined by position of toy during play with respect to midline	Tested longitudinally with seven infants: Central tasks: trend toward decreasing bimanual activity (and increasing unimanual activity) with increasing age for central tasks
				Lateral tasks: significant increase in contralateral action with increasing age
				Increase in occurrence of precision grasp and reduction in occurrence of power grasp with increasing age. Force applied during both grasp types increases with age
Klein et al. 2011 (30)	Instrumented block sorting toy, sensorized with force sensors, and infra-red proximity sensors	Age range not specified	Applied force on object lid as a function of shape and location	Tested with nine blind-folded healthy adult volunteers, showed significant performance improvement with learning
			Correct insertion of object, task completion time, number of mistrials, and percentage of time spent far from the target
Campolo et al. 2012 (31)	Instrumented block-box toy, sensorized with magneto-inertial sensors	12–36 months old	Tracking orientation during object placement	Tested with four healthy infants (14–25 months old) for acceptability
			Vertical and horizontal alignment errors and insertion time
Serio et al. 2012 (33)	Commercially bought horseshoe-shaped toy, sensorized with silicon chamber for pressure measurement (0–5 psi)	4–9 months old	Bimanual applied pressure during power grasp	Not formally tested with infant subjects