The present study deals with the effect of Mental Practice (MP) along with Physical Practice (PP) and physical practice alone in post stroke patients.
When analysis was done for demographic information of participants, no statistically significant difference was found showing that subjects are matched for baseline characteristics. There is no significant difference between pre FMA score in both the groups at baseline level. There is statistically significant difference within pre and post FMA score in both the groups, which shows that mental practice combine with physical practice and physical practice alone both are effective in post stroke patients.
When comparison was done between post FMA score in both the groups it was found that after 6 weeks of intervention experimental group has better prognosis than control group.
Although upper limb function improvements were seen in both the treatment group (physical practice alone or combined together with mental practice) in post stroke patients but it was seen in this study that when physical practice combined with mental practice (or mental imagery) in the treatment protocol, a greater amount of improvement in upper limb function was noted after 6 weeks of intervention. Therefore the null hypothesis is rejected and thus the alternate hypothesis is accepted.
The changes were found in this study clinically significant. Indeed after intervention, patients reported performing Activities of daily living (ADL’s) with their affected hands.
Finding of this study is supported by previous case report done by Stephen J Page et al. who suggested that that mental practice is a potentially useful method of practicing motor skills [24
Similar finding where functional improvements were also consistent with the speculations of Page, who suggested that functional outcome could be enhanced by mental practice and they were consistent with functional improvements observed in other mental practice studies [25
] suggested that mental practice is effective because it augments existing motor schema, subjects participating in a regimen combining mental practice and Physical practice showed large reductions in affected arm impairment as measured by the FMAS, and large increases in movement as measured by the ARAT [25
The reason behind better improvement in mental practice group is thought to provide its impact by atleast 2 independent but interrelated mechanisms. First, stroke patients have been shown for decades to not use their more affected arms, even when capable of doing, a phenomenon traditionally termed “hemiakinesia”, However, MP use was recently shown to increase affected arm use, thus overcoming this movement suppression phenomenon [29
The second hypothesized mental practice mechanism is use-dependent brain reorganization, in which new cortical areas are recruited to assist in movement of the affected arm. Results of Previous study show that this phenomenon occurs with a variety of task specific protocols, even of a brief duration, including mental practice, and that motor changes co-relate with cortical changes [30
Frequent practice of a skill causes improved motor performance. Mental practice, when combined with physical practice, has been shown to be even more effective in improving motor performance than physical practice alone. One viable hypothesis for this effect is that, during mental practice, concurrent activity occurs in the musculature and in the appropriate neuromotor pathways [32
This correlative neuromotor activity occurs with repetitive physical practice and is responsible for the motor performance improvements that individuals exhibit after mental practice. It was also believe that the patient's improvements between the pretests and the posttest occurred because the patient, through mental practice, was provided with additional practice of functional tasks using the affected arm.
On a physiological level, we believe that this practice caused priming of the motor cortex and appropriate activation of the neuromotor pathways, which resulted in the patient's improvements.
Another reason behind better recovery in experimental group may be due to additional feedback such as auditory which was provided, improves motor learning. Feedback can inform individuals about the accuracy and progress of their performance. In addition, feedback can motivate them by affecting their perceptions of competence and accomplishment [37
Jeannerod et al. implemented verbal information because current motor cognition theories, which suggest that language resonates with motor representations and activation of motor areas, can therefore be achieved through verbal route [38
Mental Practice itself functions as feedback and exerts a direct effect on the central nervous system. Because imagery and movement have been shown to be functionally equivalent, mental images like those used in MP could help in the process of engram formation. This image would then create a perception of motor performance that would activate the "automatic monitoring centre" and facilitate the consolidation of engram programming [39
In our opinion MP could be used to augment the frequency of repetition of movement at a cerebral level, with no increase in the physical demand for the patient. It could also be useful in maintaining the results achieved.