Immediate effect of contactual hand-orientating response facilitation on wrist muscle activity in individuals with chronic stroke and severe motor deficits

Purpose: Contactual hand-orientating response (CHOR) is a fundamental component of the Bobath concept which has been reported to promote hand function. This study aimed to assess activity and co-activation during CHOR facilitation of extensor digitorum (ED) which represented wrist extensors, and flexor digitorum superficialis (FDS) which represented wrist flexors. Method: CHOR facilitation of the paretic hand in 18 patients with chronic stroke with severe upper limb motor deficits, active contraction in the non-paretic hand and 18 healthy individuals wrist extensor and flexor muscles were compared using surface electromyography. Results: The co-contraction index of wrist extensors and flexors in the paretic hand in patients with chronic stroke was significantly greater during CHOR facilitation than in the healthy individuals (mean (SD)=51.88 (6.02) and 46.75 (5.50), respectively), p=0.012). Significantly greater wrist flexor and extensor muscle activity was seen in the paretic hand during CHOR facilitation compared with resting (median=0.803 vs 0.133; median=0.856 vs 0.225, respectively) (p<0.001). Conclusion: CHOR facilitation appears to selectively enhance wrist extensor and wrist flexor activity in patients with stroke despite showing a greater co-activation. These findings support the immediate effect of movement facilitation to enhance muscle activity in patients with severe motor deficits post stroke.