Action Observation

Action observation therapy has been used in the treatment of patients with neurological disorders, such as stroke and SCI (Peng et al. 2019). In action observation therapy, patients are asked to observe motor actions carried out by another individual and then attempt to perform the same task themselves (Peng et al. 2019). As an example, patients may watch a video clip that shows an individual stretching out their hand to pick up a cup and then try to attempt the movement themselves (Borges et al. 2018). This process is thought to enhance rehabilitation through the mirror neuron system by activating central representations of actions to increase cortical excitability in the primary motor cortex (Peng et al 2019; Kim & Kim 2015). A few studies have evaluated the efficacy of action observation therapy in motor relearning following stroke and found some benefits in upper limb function (Kuk et al. 2016; Zhu et al. 2015; Sale et al. 2014; Ertlet et al. 2007). However, few studies have investigated the efficacy of action observation therapy in SCI patients.

The methodological details and results from one post test are outlined in Table 5.

Author Year

Country
Research Design

Score
Total Sample Size

Methods Outcome
Scandola et al. 2014

Italy

Post Test

N=48

Population: Tetraplegic group (n=16): Mean age: 45.9±14.5 yr; Gender: males=10, females=6; Mean Spinal Cord Independence Measure-III (SCIM-3): 33.4±16.8; Level of injury: AIS A=8, AIS B=8; Severity of Injury: C4-C6; Mean time since injury: 13.3±10.9 yr.  Paraplegic group (n=16): Mean age: 50.0±13.2 yr; Gender: males=12, females=4; Level of injury:  AIS A=14, AIS B=2; Severity of Injury: T1-L4; Mean time since injury: 18.5±12.4 yr.

Healthy controls (n=16): Mean age: 43.1±16.9 yr; Gender: males=8, females=8.

Intervention: Induction of the Rubber Hand Illusion (RHI) through synchronous multisensory visuo-tactile bodily stimulation (cheek and rubber hand vertically aligned with real hand) to determine the correlation with plastic remapping.

Outcome Measures: 6-item questionnaire; Illusion Related Questions (IRQ), Illusion Control Questions (ICQ), Big-Five Inventory (BFI-10), Tellegen Absorption Scale (TAS).

1.     Three-way interaction between number of drifts, group and stimulation-type and body part was significant (p=0.02).

2.     Tetraplegic group showed significantly greater values in IRQ than ICQ responses in hand-synchronous (p=0.0001), hand-asychronous (p=0.026), and face-synchronous conditions (p=0.024).

3.     In the paraplegic group, significant values found in IRQ over ICQ responses in hand-synchronous (p<0.0001) and hand-asychronous (p=0.0002); whereas in healthy group only found significance in hand-synchronous condition (p<0.0001).

4.     No statistically significant correlations were found between drifts or questionnaire responses and the TAS, the BFI-10, the SCIM-3 and the NLI.

Discussion

There is very limited evidence to support action observation as a rehabilitative therapy for individuals with SCI. The results from Scandola et al. (2014) demonstrate significant improvements in feelings of hand ownership, however, the functional relevance of this remains unclear. As such, further research is necessary to determine the efficacy of action observation therapy in SCI.

Conclusion

There is level 4 evidence (from one post-test study: Scandola et al. 2014) that showed that the induction of the rubber hand illusion through synchronous multisensory visuo-tactile bodily stimulation resulted in ownership of the hand.