Table 2.

Virtual coach actions related to state transitions and also permanence in the same state

State transition no.	Rules	Actions
1	$Stat{e}_{\mathit{prev}}=o$  $State=o$ $Time>t{h}_{\mathit{pos}}$	Patient not well-positioned: VC suggests body repositioning; position rectangle in red color.
2	$Stat{e}_{\mathit{prev}}=\mathcal{S}/\{o,e,tg\}$  $State=o$	Patient moves away from correct position: VC suggests body re-positioning; position rectangle in red color.
3	$Stat{e}_{\mathit{prev}}=o$  $State=i$	Patient well-positioned: position rectangle in green color; VC gives exercise directions.
4	$Stat{e}_{\mathit{prev}}=i$  $State=e$	Exercise beginning: VC displays target position marker (green).
5	$Stat{e}_{\mathit{prev}}=\mathcal{S}/\{o,i,tg\}$  $State=e$	Patients stops moving: VC proposes movement repetition.
6	$Stat{e}_{\mathit{prev}}=e$  $State=n$	The VC starts evaluating patient’s performance and asks one to reach the target position.
7	$Stat{e}_{\mathit{prev}}=\{tr,se,td,n\}$  $State=\{tr,se,td,n\}$ $Time>t{h}_{\mathit{tg}}$	Patient takes too much time reaching the target position: VC encourages patient to reach the target.
8	$Stat{e}_{\mathit{prev}}=\{tr,se,td,n\}$  $state=tg$	Patient reaches the target: VC praises the patient; target position marker in blue color.
9	$Stat{e}_{\mathit{prev}}=\{tr,se,td,n\}$  $State=tr$	Patient describes trunk rotation: VC suggests posture correction; it displays trunk compensation marker (red).
10	$Stat{e}_{\mathit{prev}}=\{tr,se,td,n\}$  $State=se$	Patient describes shoulder elevation: VC suggests correction; VC displays shoulder compensation marker (red).
11	$Stat{e}_{\mathit{prev}}=\{tr,se,td,n\}$  $State=td$	Patient describes displaces the torso: VC suggests posture correction; VC displays trunk compensation marker (red).