Table 1.

State-of-the-art perturbation training techniques.

Perturbation technology/system	Perturbating principle	Direction of perturbation	Anticipatory strategy	Portability	Parameter reproducibility	Resultant of perturbation action	Cited articles
Motorized waist pulls	Lateral fall perturbation	Bi	Yes	Yes	Yes	Compensatory stepping	Borrelli et al. [4], Yungher et al. [5], Young et al. [6]
Rubber sheet with motor	Platform beneath pulled	Uni	No	Yes	Yes	Compensatory stepping	Weerdesteyn et al.[7]
Lean and release	Cable release	Uni	No	Yes	Yes	Compensatory stepping	Schinkel-Ivy et al. [8], Mansfield et al. [9], Chan et al. [10], Inness et al. [11], Rydalch et al. [12], Inness et al. [13], Lakhani et al. [14]
Tether release	Cable release	Uni	No	Yes	Yes	Compensatory stepping	Van Liew et al. [15], Legg et al. [16], Cortes et al. [17]
Radboud falls simulator	Motorized platform	Multi	Yes	No	Yes	Compensatory stepping	Schinkel-Ivy et al. [18], de Kam et al. [19]
Foam	Foam density	Multi	No	Yes	No	Adjusting weight-bearing joints	Huang et al. [20]
Biodex	Platform inclines	Multi	Yes	No	Yes	Adjusting weight-bearing joints	Gusi et al. [21], Nel et al. [22]