Table 2.

Overview of commonly-used accelerometers

Name	Manufacturer	Type*	Size and weight	Cost†	Placement	Epoch length	Memory capacity	What it provides	Validity/reliability‡
Actigraph Model 7164 [formerly CSA, MTI]	Actigraph LLC Pensacola, FL	Uniaxial	5.1×41×1.5 cm 45.5 g	N/A for purchase	Usually hip, also ankle/wrist	Records activity in 5 s to 1 min. epochs	Records up to 22 d of data when using 1 min. epochs	Activity counts Energy expenditure	Welk et al., 2000 Welk et al., 2004 Freedson et al., 1998 Hendelman et al., 2000 Crouter et al., 2006 Rothney et al., 2008a,b Moeller et al., 2008 McClain et al., 2007 Esliger and Tremblay, 2006
Actical	Mini-Mitter Sunriver, OR	Uniaxial; Omni-directional	2.8×2.7×1.0 cm 17.5 g	$950 w/software $450 per unit	Wrist, hip, or ankle	Records epochs from 15 s to 1 min.	Stores up to 45 d of data using 1 min. epochs	Activity counts Step counts Energy expenditure	Welk et al., 2004 Crouter et al., 2006 Rothney et al., 2008a,b Esliger and Tremblay, 2006 Esliger et al., 2007 Heil, 2006 Klippel NJ, 2003
Actiwatch AW16 or AW64	Mini-Mitter Sunriver, OR	Uniaxial; Omni-directional	2.8×2.7×1.0 cm 16 g	$1966 w/software $985 per unit	Hip or wrist	Records epochs 15 s to 15 min	AW16 records up to 11 d of data using 1 min. epochs; AW64 up to 45 d	Activity counts Sleep quality	Chen et al., 2003 Gironda et al., 2007
Actitrac	IM Systems Baltimore, MD	Biaxial	5.6×3.8×13 cm 34 g	$799 per unit $399 for software $99 for cable	Wrist	Records epochs 2 s to 2 min	Records up to 44 d of data when using 1 min. epochs	Activity counts	Welk et al., 2003
Biotrainer	IM Systems Baltimore, MD	Biaxial	7.6×5×2.2 cm 51.1 g	$199 per unit $199 for software $99 for cable	Hip	Records activity in 15 s to 5 min. epochs	Records up to 22 d of data when using 1 min. epochs	Activity counts Converted into ‘g’ units or kilocalories expended	Welk et al., 2000 Welk et al., 2003
GT1M Actigraph	Actigraph LLC Pensacola, FL	Biaxial	33×3.7×1.8 cm 27 g	$335 per unit $349 for software	Hip or waist	Records activity in epochs of 1 s to several minutes	Records up to 378 d of data when using 1 min. epochs	Activity counts Step counts Energy expenditure Sleep quality	Corder et al., 2007 Rothney et al., 2008a,b
Actiwatch Spectrum	Mini-Mitter Sunriver, OR	Uniaxial; Omni-directional	49×3.7×1.4 cm 29.8 g	$1599 per unit $399 for reader/charger unit	waist	Records activity in 15 s to 1 min. epochs	Records up to 36 d of data when using 1 min. epochs	Activity counts sleep quality
Actiwatch 2	Mini-Mitter Sunriver, OR	Uniaxial; Omni-directional	4.4×23×1 cm 16.1 g (with band)	$999 per unit $299 reader	waist	Records activity in 15 s to 1 min. epochs	Records up to 30 d of data when using 1 min. epochs	Activity counts Sleep quality
RT3-Triaxial Research Tracker [formerly R3D]	Stayhealthy Inc. Monrovia, CA	Triaxial	7.1×5.6×2.8 cm 65.2 g	$200 per unit $300 for docking station	Hip or waist	Records activity in 1 s to 1 min. epochs	Records up to 7 d of data when using 1 min. epochs	Activity counts for each plane: vertical, horizontal, mediolateral Energy expenditure	Rothney et al., 2008a,b Esliger and Tremblay, 2006 Powell and Rowlands, 2004

Note. s = seconds; min = minutes, d = days.

^*Uniaxial refers to accelerometers which measure acceleration in one plane, usually vertical to the ground. Omni-directional refers to a single beam accelerometer that detects acceleration primarily in one plane but also incidentally in two others. Biaxial and triaxial refer to accelerometers which measure acceleration in two or three planes respectively.

^†price quotes as of August, 2008.

^‡Adult population articles concerning physical activity only.