Several studies have addressed the use of augmented feedback such as biofeedback with spinal cord injured populations.  Van Dijik et al. (2005) conducted a systematic review of RCTs on the effect of augmented feedback on motor function of the affected upper extremity in rehabilitation patients. Much of the information about augmented feedback comes from the motor learning literature where it has been noted that feedback combined with practice is a potent variable for affecting motor skill learning (Newell 1991; Schmidt & Lee 1999).  There are two types of performance-related information or feedback.  The first type of feedback, task intrinsic or inherent feedback, is sensory-perceptual information and is a natural part of performing a skill.  The second type of feedback is augmented feedback or information-based extrinsic or artificial feedback.  Augmented feedback refers to enhancing task intrinsic feedback with an external source (Schmidt & Lee 1999; Magill 2001), such as a therapist or device (biofeedback or timer) (van Dijik et al. 2005).  It has been suggested that augmented feedback may have practical implications for rehabilitation therapy since re-acquisition of motor skills is an important part of functional motor recovery (Winstein 1991; Kilduski and Rice 2003; Jarus 1994; Jarus and Ratzon 2005).

The ability to use intrinsic feedback to guide performance is impaired in patients with cognitive and perceptual impairments (Flinn & Radomski 2002). In persons who are compromised by neurological sensory impairments, augmented feedback is important (Sabari 2001). 

Asystematic review (van Dijik et al. 2005) found three randomized clinical controlled trials which studied augmented feedback in the SCI population (Klose et al. 1993; Klose et al. 1990 and Kohlmeyer et al.1996).  In our literature search we were able to find an additional two other studies with lower level of evidence that studied augmented feedback applications.

Table: Augmented Feedback on Motor Functions

Discussion

All of the studies concluded that there was no evidence of the effectiveness of the use of augmented feedback to improve arm function in rehabilitation. 

van Dijik et al. (2005) in their systematic review recommended the following be considered in future research in this area:

• future studies need to focus on content, form and timing of the augmented feedback to clarify its importance  in rehabilitation
• studies should recognize the difference between performance and learning effects concerning reacquisition of motor skills by re-examining the study population after a follow up period

Conclusion 

• There is level 1a evidence (from 2 RCTs) that augmented feedback is not effective in improving upper limb function in tetraplegia.

• Augmented feedback does not improve motor function of the upper extremity in SCI rehabilitation patients.